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  • richardmitnick 12:15 pm on March 5, 2017 Permalink | Reply
    Tags: , , , , , Nautilus   

    From Nautilus: “Gravity’s Kiss – The third ripple. 

    Nautilus

    Nautilus

    3.5.17
    Harry Collins

    Gravity’s Kiss by Harry Collins, is published by the MIT Press.

    LIGO bloc new
    Caltech/MIT Advanced aLigo Hanford, WA, USA installation
    Caltech/MIT Advanced aLigo Hanford, WA, USA installation
    Caltech/MIT Advanced aLigo detector installation Livingston, LA, USA
    Caltech/MIT Advanced aLigo detector installation Livingston, LA, USA

    VIRGO Collaboration bloc
    VIRGO Gravitational Wave interferometer, near Pisa, Italy
    VIRGO Gravitational Wave interferometer, near Pisa, Italy [not yet operational]

    Cornell SXS, the Simulating eXtreme Spacetimes (SXS) project
    Cornell SXS, the Simulating eXtreme Spacetimes (SXS) project

    Gravitational waves. Credit: MPI for Gravitational Physics/W.Benger-Zib
    Gravitational waves. Credit: MPI for Gravitational Physics/W.Benger-Zib

    Gravitational waves are finding their way to the general public. There is massive television news coverage with never a doubt expressed; gravitational waves have simply “been detected”—exciting but no more dubious than, say, the moon landing. What is happening is that gravitational waves are being “domesticated” in the same way as black holes or the Higgs have been domesticated. Everyone knows what a black hole is—it is a feature of everyone’s day-to-day life embedded in a “semantic net” that includes “the cosmos,” “the big bang,” “Stephen Hawking,” “brilliant scientists,” “Einstein,” “space,” “alternative universes,” “time travel,” “worm-holes,” “astronomy,” “rockets,” and “being sucked into things”—and this is in spite of the fact that, before The Event, no black hole had been observed except by inference. As for the Higgs, everyone knows that it was found by the huge and brilliant team at CERN, but, familiar as it is, no one knows what it is. I know it is the last piece in the jigsaw puzzle of the particle “zoo” known as the standard model, but what I have is “beer-mat knowledge,” good for answering questions in Trivial Pursuit but that’s about it. On the other hand, the fact that we can imagine encountering questions about black holes and the Higgs while playing Trivial Pursuit is one of the things that makes them real: all this familiar knowledge makes stuff real. The moon landing, note, is pretty real for everyone but, just as in the case of what is building in respect of The Event, there are conspiracy theories about that too; and, just as in this case, you have to stray from the mainstream to find them.

    On Friday I gather a good selection of the United Kingdom print newspapers; they are big contributors to the domestication process. The Guardian is a broadsheet for the left-liberal middle classes and its news section is 38 pages long. It gives the story the lead and whole of page 11. It had also given it the whole of page 3 on Wednesday, building the story on the rumors. On Saturday, The Guardian’s regular political cartoon features the Syrian peace talks represented as some kind of funny-looking celestial object with the caption: “Not gravitational waving but gravitational drowning.” Thus do gravitational waves spread into the ordinary language.

    1
    EXTRA! EXTRA!Newspaper front pages from around the world.
    Courtesy of LIGO

    The Independent has a similar readership to The Guardian but has a smaller tabloid format with 72 pages. It gives the story the entire page 1 and pages 6–8; it opines that this is “one of the greatest achievements in human history.”

    The Telegraph is another broadsheet, with 38 pages in its news section. It is a right-wing, patriotic paper for the educated. It makes gravitational waves the second story on page 1, leading with:

    A British scientist who was pivotal in the project to detect gravitational waves could not celebrate the momentous discovery with colleagues because he is suffering from dementia.

    This, of course, is Ron Drever. The paper also gives up pages 10 and 11 to the story.

    Martin Rees, the Astronomer Royal, writes columns in The Independent and the Telegraph. He opines that this is of similar importance to the discovery of the Higgs; most other commentators say it is much more important than the Higgs, but Rees has long been said by gravitational wave physicists to be less than enthusiastic about the enterprise.

    The Daily Mail is a “little Englander” tabloid with 92 pages serving those with strong right-wing opinions. It gives the story half of page 10, mistakenly claiming that Einstein predicted that colliding stars would generate gravitational waves that could be detected on Earth, whereas he actually thought they would remain completely undetectable.

    The Mirror is a left-leaning tabloid with 80 pages. It gives the story most of page 21 but says that LIGO was invented by Thorne and Weiss, missing out on Drever.

    The Sun is a tabloid with 60 pages that began its life by publishing photographs of topless models on the notorious “page 3” (now dropped). The only science I could find was on the bottom third of page 15, head-lined: “Top Prof Dies in Rubber Suit with Dog Lead Round Neck.” The “Top Prof” does not seem to have been one of the gravitational wave team.

    The Guardian website of February 12 includes a hilarious cartoon—one of a series called “First Dog on the Moon,” which anticipates one of my major sociological theses. The fourth panel of the cartoon opines:

    Obviously we can’t see these waves—the only way we know they are real is by using another extremely sensitive device which detects scientists having feelings of excitement.

    The excitement evoked in scientists by a gravitational wave is calibrated using the marginally smaller effect of a cheese salad sandwich as a standard candle.

    Later I will discover that my major thesis about social construction, which turns on pointing out that no gravitational waves were seen but merely a few numbers that were interpreted as gravitational waves, has been thoroughly anticipated (albeit on a strange, flat-earther YouTube channel that appears to treat conspiracy theories as an art form). It claims scientists have not seen gravitational waves, nor has their machine seen gravitational waves, but that the machine produces lots of glitchy noises out of which they have picked one and interpreted it as a gravitational wave.

    A member of the LIGO team has put together a collection of newspaper front pages from around the world. And, as though to put an indelible stamp on the soon to be taken for granted nature of this exotic phenomenon, in the United States the discovery is presented on Saturday Night Live and The Tonight Show, and, on Saturday, February 13, the humorous U.S. radio show A Prairie Home Companion devotes about five minutes to gravitational waves. Gravitational waves have arrived!

    The physicists continue to do my job for me by gathering more indications of the domestication of gravitational waves. On February 16, a French (presumably humorous) website normalizes the waves in contemporary fashion by calling for a ban on them and the distribution of protective helmets. This is a Google translation from the French with my minor edits:

    “For a Moratorium on Gravitational Waves

    Bringing together hundreds of independent researchers, the “Collective for a moratorium on gravitational waves” (COMOG) sent us this platform. We publish it verbatim in our columns:

    In recent days, highlighting the “gravitational waves” continues to make the press headlines. Everyone welcomes this alleged “scientific breakthrough,” which was published in the Physical Review Letters, a journal under orders of the nuclear lobby.

    Now, our collective, consisting of independent researchers who wish to remain anonymous for their own reasons, is concerned about the apparent toxicity of gravitational waves.

    To date, there is in fact no serious study establishing the actual safety of these waves. That is why we propose an action plan of four points.

    1. We recall, first, that the oscillations of the curvature of space-time can present health risks found, especially on the neurological system of employees too long exposed to the gravitational waves. It is appropriate in this case to call for the government to strictly enforce the Labour Code, to limit the time of exposure to gravitational waves, and equip the wage earners with protective helmets.

    2. To these health risks are added, as often environmental, of deleterious economic effects. The curvature of space-time is likely to cause untoward inconvenience, especially in the field of transport and travel. An example: If space-time is curved in the wrong direction when one performs a trip from Paris to Bordeaux, the journey can last more than 25 hours, according to our estimates. Gravitational waves expose the French economy to serious danger that cannot be underestimated.

    3. It appears that the production of gravitational waves calls for masses of matter and energy that are absolutely astounding: black holes, neutron stars, washing machines, etc. We ask that the environmental and climate impact of gravitational waves be measured in France by an independent body and a carbon footprint be determined as quickly as possible.

    4. As a result, we ask Ségolène Royal, Minister of Environment, Energy and the Sea, responsible for international relations on the climate, to apply the constitutional principle of precaution, and to take by decree related measures that are defined and recommended in principle 15 of the Rio Declaration. It seems to us urgent that France decide on a moratorium on gravitational waves.

    If the government does not abide by these basic precautions, peaceful COMOG teams will be forced to resort to direct action. Within six months, we will proceed to the systematic dismantling of gravitational wave antennas. Our teams of volunteer harvesters shall uproot the plants of space-time curvatures. Finally, we will not hesitate to leave Paris to set up a zone to defend Proxima Centauri, even against the advice of the prefect.

    We call upon our fellow citizens to join our fight. Gravitational waves, no thank you!”

    On February 18, the Huddersfield Daily Examiner (Huddersfield is a town in North England with a football club—“Huddersfield Town”—all about as provincially English as can be) carries a story about the “Huddersfield Town Supporters Association” (HTSA). It includes:

    Our HTSA column last week touched upon the subject of regional supporters groups and their recent cosmic rise in popularity. The Laser Interferometer Gravitational-Wave Observatory (LIGO) can probably demonstrate whether this is due to colliding Black Holes over Bexleyheath.

    And Barack Obama had tweeted on February 11:

    Einstein was right! Congrats to @NSF and @LIGO on detecting gravitational waves—a huge breakthrough in how we understand the universe.

    At the forthcoming American Physical Society (APS) meeting, Dave Reitze, the director of LIGO, will present a slide showing a woman wearing a dress patterned with the waveform, an Australian competition swimmer with the waveform on his swim-cap, and a New York advertisement for apartments.

    2
    Fashionably wavy. More domestication of gravitational waves. No image credits.

    I attend two meetings in March: a general relativity 100th anniversary meeting at Caltech and the LIGO-Virgo collaboration meeting in Pasadena. Of course, the cat is now out of the bag so a big topic at the Caltech meeting is The Event. I follow Barry Barish onto the platform; he describes the technicalities and I talk about the way small science and big science had combined to create this possibility, with Barish bringing about the necessary transformation, and I talk about what it meant for me as a sociologist to be confronted by such a sudden and certain result. At neither meeting is there any criticism but the LVC is selling huge numbers of T-shirts and polo shirts with the waveform of The Event printed or embroidered on them: The waveform is becoming an icon! Many more such garments will be sold at the April APS meeting.

    At the March meeting of the APS—a much larger meeting than the April meeting I am going to attend—a group of physicists who have nothing to do with LIGO or gravitational waves performed a song based on the Neil Diamond/Monkees’ “I’m a Believer.” The lyrics are as follows:

    “I’m a LIGO Believer.” Lyrics: Marian McKenzie. Tune: “I’m a Believer,” by Neil Diamond (courtesy Marian McKenzie).

    I thought waves of gravity were fairy tales—fine for dilettantes, but not for me.
    What’s the use of searching?
    Noise is all you’ll find.
    I don’t want to clutter up my mind—

    [Chorus:] Then I saw the graph—Now I’m a believer!
    You can laugh, and hold me in scorn.
    I’m convinced, oooh, I’m a believer
    In Weiss, Reitze, Drever, Gonzalez, and Thorne!

    Einstein spoke of grav wave propagation.
    Weber tried to find them on the moon.
    BICEP2 announced them,
    Then said “Never mind.”
    —Do you wonder I was disinclined?

    [Sing chorus] [instrumental interlude] and repeat”

    The whole song can be seen and heard on YouTube.

    3
    surfing the googleEnormous spike in interest in gravitational waves around February 11. No image credit.

    What about social media? Google Trends (see chart above) shows the huge spike in interest in gravitational waves around the February 11 press conferences by tracking hits on Google. Unfortunately, we have only the normalized trend, the scale having a maximum of 100, not absolute numbers.

    4
    Breaking the internet. The enormous spike in interest in gravitational waves compared to hits for Kim Kardashian.

    Gravitational waves are not, however, about to take over the popular imagination. The chart above shows the same spike in comparison to Google hits for Kim Kardashian, the reality TV star. Gravitational waves’ enormous spike is a mere 2 percent as high as Kardashian’s peak performance and only about 5 percent as high as her average day-to-day score. Aside from the spike, gravitational waves score zero when compared to Kardashian’s average.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Welcome to Nautilus. We are delighted you joined us. We are here to tell you about science and its endless connections to our lives. Each month we choose a single topic. And each Thursday we publish a new chapter on that topic online. Each issue combines the sciences, culture and philosophy into a single story told by the world’s leading thinkers and writers. We follow the story wherever it leads us. Read our essays, investigative reports, and blogs. Fiction, too. Take in our games, videos, and graphic stories. Stop in for a minute, or an hour. Nautilus lets science spill over its usual borders. We are science, connected.

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  • richardmitnick 10:11 am on March 1, 2017 Permalink | Reply
    Tags: , , , , , MOND - Modified Newtonian Dynamics, Mordehai Milgrom, Nautilus,   

    From Nautilus: “The Physicist Who Denies that Dark Matter Exists” 

    Nautilus

    Nautilus

    3.1.17
    Oded Carmeli

    1
    Mordehai Milgrom Credit: Weizmann Institute

    Maybe Newtonian physics doesn’t need dark matter to work, but Mordehai Milgrom instead.

    He is one of those dark matter people,” Mordehai Milgrom said about a colleague stopping by his office at the Weizmann Institute of Science. Milgrom introduced us, telling me that his friend is searching for evidence of dark matter in a project taking place just down the hall.

    “There are no ‘dark matter people’ and ‘MOND people,’” his colleague retorted.

    “I am ‘MOND people,’” Milgrom proudly proclaimed, referring to Modified Newtonian Dynamics, his theory that fixes Newtonian physics instead of postulating the existence of dark matter and dark energy—two things that, according to the standard model of cosmology, constitute 95.1% of the total mass-energy content of the universe.

    This friendly incident is indicative of (“Moti”) Milgrom’s calmly quixotic character. There is something almost misleading about the 70-year-old physicist wearing shorts in the hot Israeli summer, whose soft voice breaks whenever he gets excited. Nothing about his pleasant demeanor reveals that this man claims to be the third person to correct Newtonian physics: First Max Planck (with quantum theory), then Einstein (with relativity), now Milgrom.

    This year marks Milgrom’s 50th year at the Weizmann. I visited him there to learn more about how it feels to be a science maverick, what he appreciates about Thomas Kuhn’s The Structure of Scientific Revolutions, and why he thinks dark matter and dark energy don’t exist.

    What inspired you to dedicate your life to the motion of stars?

    I remember very vividly the way physics struck me. I was 16 and I thought: Here is a way to understand how things work, far beyond the understanding of my peers. I was drawn to the beauty of finding deeper reasons for events, to the aesthetics of discovering hidden symmetries. It wasn’t a long-term plan. It was a daily attraction. I simply loved physics, the same way other people love art or sports. I never dreamed of one day making a major discovery, like correcting Newton.

    I had a terrific physics teacher at school, but when you study textbook material, you’re studying done deals. You still don’t see the effort that goes into making breakthrough science, when things are unclear and advances are made intuitively and often go wrong. They don’t teach you that at school. They teach you that science always goes forward: You have a body of knowledge, and then someone discovers something and expands that body of knowledge. But it doesn’t really work that way. The progress of science is never linear.

    How did you get involved with the problem of dark matter?

    Toward the end of my Ph.D., the physics department here wanted to expand. So they asked three top Ph.D. students working on particle physics to choose a new field. We chose astrophysics, and the Weizmann Institute pulled some strings with institutions abroad so they would accept us as postdocs. And so I went to Cornell to fill my gaps in astrophysics.

    After a few years in high energy astrophysics, working on the physics of X-ray radiation in space, I decided to move to yet another field: The dynamics of galaxies. It was a few years after the first detailed measurements of the speed of stars orbiting spiral galaxies came in. And, well, there was a problem with the measurements.

    To understand this problem, one needs to wrap one’s head around some celestial rotations. Our planet orbits the sun, which, in turn, orbits the center of the Milky Way galaxy. Inside solar systems, the gravitational pull from the mass of the sun and the speed of the planets are in balance. By Newton’s laws, this is why Mercury, the innermost planet in our solar system, orbits the sun at over 100,000 miles per hour, while the outermost plant, Neptune, is crawling at just over 10,000 miles per hour.

    Now, you might assume that the same logic would apply to galaxies: The farther away the star is from the galaxy’s center, the slower it revolves around it; however, while at smaller radiuses the measurements were as predicted by Newtonian physics, farther stars proved to move much faster than predicted from the gravitational pull of the mass we see in these galaxies. The observed gap got a lot wider when, in the late 1970s, radio telescopes were able to detect and measure the cold gas clouds at the outskirts of galaxies. These clouds orbit the galactic center five times farther than the stars, and thus the anomaly grew to become a major scientific puzzle.

    One way to solve this puzzle is to simply add more matter. If there is too little visible mass at the center of galaxies to account for the speed of stars and gas, perhaps there is more matter than meets the eye, matter that we cannot see, dark matter.

    2
    MOND in the MakingMilgrom’s notes from 1981. On the left, each line represents the data from a separate galaxy. On the right is the MOND prediction, which is the line going through the data points.
    Mordehai Milgrom

    What made you first question the very existence of dark matter?

    What struck me was some regularity in the anomaly. The rotational velocities were not just larger than expected, they became constant with radius. Why? Sure, if there was dark matter, the speed of stars would be greater, but the rotation curves, meaning the rotational speed drawn as a function of the radius, could still go up and down depending on its distribution. But they didn’t. That really struck me as odd. So, in 1980, I went on my Sabbatical in the Institute for Advance Studies in Princeton with the following hunch: If the rotational speeds are constant, then perhaps we’re looking at a new law of nature. If Newtonian physics can’t predict the fixed curves, perhaps we should fix Newton, instead of making up a whole new class of matter just to fit our measurements.

    If you’re going to change the laws of nature that work so well in our own solar system, you need to find a property that differentiates solar systems from galaxies. So I made up a chart of different properties, such as size, mass, speed of rotation, etc. For each parameter, I put in the Earth, the solar system and some galaxies. For example, galaxies are bigger than solar systems, so perhaps Newton’s laws don’t work over large distances? But if this was the case, you would expect the rotation anomaly to grow bigger in bigger galaxies, while, in fact, it is not. So I crossed that one out and moved on to the next properties.

    I finally struck gold with acceleration: The pace at which the velocity of objects changes.

    We usually think of earthbound cars that accelerate in the same direction, but imagine a merry-go-round. You could be going in circles and still accelerate. Otherwise, you would simply fall off. The same goes for celestial merry-go-rounds. And it’s in acceleration that we find a big difference in scales, one that justifies modifying Newton: The normal acceleration for a star orbiting the center of a galaxy is about a hundred million times smaller than that of the Earth orbiting the sun.

    For those small accelerations, MOND introduces a new constant of nature, called a0. If you studied physics in high school, you probably remember Newton’s second law: force equals mass times acceleration, or F=ma. While this is a perfectly good tool when dealing with accelerations much greater than a0, such as those of the planets around our sun, I suggested that at significantly lower accelerations, lower even than that of our sun around the galactic center, force becomes proportional to the square of the acceleration, or F=ma2/a0.

    To put it in other words: According to Newton’s laws, the rotation speed of stars around galactic centers should decrease the farther the star is from the center of mass. If MOND is correct, it should reach a constant value, thus eliminating the need for dark matter.

    What did your colleagues at Princeton think about all this?

    I didn’t share these thoughts with my colleagues at Princeton. I was afraid to come across as, well, crazy. And then, in 1981, when I already had a clear idea of MOND, I didn’t want anyone to jump on my wagon, so to speak, which is even crazier when you think about it. Needless to say,” he laughs, “no one jumped on my wagon, even when I desperately wanted them to.

    Well, you were 35 and you proposed to fix Newton.

    Why not? What’s the big deal? If something doesn’t work, fix it. I wasn’t trying to be bold. I was very naïve at the time. I didn’t understand that scientists are just as swayed as other people by conventions and interests.

    Like Thomas Kuhn’s The Structure of Scientific Revolutions.

    I love that book. I read it several times. It showed me how my life’s story has happened to so many others scientists throughout history. Sure, it’s easy to make fun of people who once objected to what we now know is good science, but are we any different? Kuhn stresses that these objectors are usually good scientists with good reasons to object. It is just that the dissenters usually have a unique point of view of things that is not shared by most others. I laugh about it now, because MOND has made such progress, but there were times when I felt depressed and isolated.

    What’s it like being a science maverick?

    By and large, the last 35 years have been exciting and rewarding exactly because I have been advocating a maverick paradigm. I am a loner by nature, and despite the daunting and doubting times, I much prefer this to being carried with the general flow. I was quite confident in the basic validity of MOND from the very start, which helped me a lot in taking all this in stride, but there are two great advantages to the lingering opposition to MOND: Firstly, it gave me time to make more contributions to MOND than I would had the community jumped on the MOND wagon early on. Secondly, once MOND is accepted, the long and wide resistance to it will only have proven how nontrivial an idea it is.

    By the end of my sabbatical in Princeton, I had secretly written three papers introducing MOND to the world. Publishing them, however, was a whole different story. At first I sent my kernel paper to journals such as Nature and Astrophysical Journal Letters, and it got rejected almost off-hand. It took a long time until all three papers were published, side by side, in Astrophysical Journal.

    The first person to hear about MOND was my wife Yvonne. Frankly, tears come to my eyes when I say this. Yvonne is not a scientist, but she has been my greatest supporter.

    The first scientist to back MOND was another physics maverick: The late Professor Jacob Bekenstein, who was the first to suggest that black holes should have a well-defined entropy, later dubbed the Bekenstein-Hawking entropy. After I submitted the initial MOND trilogy, I sent the preprints to several astrophysicists, but Jacob was the first scientist I discussed MOND with. He was enthusiastic and encouraging from the very start.

    Slowly but surely, this tiny opposition to dark matter grew from just two physicists to several hundred proponents, or at least scientists who take MOND seriously. Dark matter is still the scientific consensus, but MOND is now a formidable opponent that proclaims the emperor has no clothes, that dark matter is our generation’s ether.

    So what happened? As far as dark matter is concerned, nothing really. A host of experiments searching for dark matter, including the Large Hadron Collider, many underground experiments and several space missions, have failed to directly observe its very existence. Meanwhile, MOND was able to accurately predict the rotation of more and more spiral galaxies—over 150 galaxies to date, to be precise.

    All of them? Some papers claim that MOND wasn’t able to predict the dynamics of certain galaxies.

    That’s true and it’s perfectly fine, because MOND’s predictions are based on measurements. Given the distribution of regular, visible matter alone, MOND can predict the dynamics of galaxies. But that prediction is based on our initial measurements. We measure the light coming in from a galaxy to calculate its mass, but we often don’t know the distance to that galaxy for sure, so we don’t know for certain just how massive that galaxy really is. And there are other variables, such as molecular gas, that we can’t observe at all. So yes, some galaxies don’t perfectly match MOND’s predictions, but all in all, it’s almost a miracle that we have enough data on galaxies to prove MOND right, over and over again.

    Your opponents say MOND’s greatest flaw is its incompatibility with relativistic physics.

    In 2004, Bekenstein proposed his TeVeS, or Relativistic Gravitational Theory for MOND. Since then, several different relativistic MOND formulations have been put forth, including one by me, called Bimetric MOND, or BIMOND.

    So, no, incorporating MOND into Einsteinian physics is no longer a challenge. I hear this statement still made, but only from people who parrot others, who themselves are not abreast with the developments of the last 10 years. There are several relativistic versions of MOND. What remains a challenge is demonstrating that MOND can account for the mass anomalies in cosmology.

    Another argument that cosmologists often make is that dark matter is needed not just for motion within galaxies, but on even larger scales. What does MOND have to say about that?

    According to the Big Bang theory, the universe began as a uniform singularity 13.8 billion years ago. And, just as in galaxies, observations made of the cosmic background radiation from the early universe suggest that the gravity of all the matter in the universe is simply not enough to form the different patterns we currently see, like galaxies and stars, in just 13.8 billion years. Once again, dark matter was called to the rescue: It does not emit radiation, but it does engage visible material with gravitation. And so, starting from the 1980s, the new cosmological dogma was that dark matter constituted a staggering 95 percent of all matter in the universe. That lasted, well, right until the bomb hit us in 1998.

    It turned out that the expansion of the universe is accelerating, not decelerating like all of us originally thought. Any form of genuine matter, dark or not, should have slowed down acceleration. And so a whole new type of entity was invented: Dark energy. Now the accepted cosmology is that the universe is made up of 70 percent dark energy, 25 percent dark matter, and 5 percent regular matter.

    But dark energy is just a quick fix, the same as dark matter is. And just as in galaxies, you can either invent a whole new type of energy and then spend years trying to understand its properties, or you can try fixing your theory.

    Among other things, MOND points to a very deep connection between structure and dynamics in galaxies and cosmology. This is not expected in accepted physics. Galaxies are tiny structures within the grand scale of the universe, and those structures can behave differently without contradicting the current cosmological consensus. However, MOND creates this connection, binding the two.

    This connection is surprising: For whatever reason, the MOND constant of a0 is close to the acceleration that characterizes the Universe itself. In fact, MOND’s constant equals the speed of light squared, divided by the radius of universe.

    So, indeed, to your question, the conundrum pointed to is valid at present. MOND doesn’t have a sufficient cosmology yet, but we’re working on it. And once we fully understand MOND, I believe we’ll also fully understand the expansion of the universe, and vice versa: A new cosmological theory would explain MOND. Wouldn’t that be amazing?

    What do you think about the proposed unified theories of physics, which merge MOND with quantum mechanics?

    These all hark back to my 1999 paper on ‘MOND as a vacuum effect’, where it was pointed out that the quantum vacuum in a universe such as ours may produce MOND behavior within galaxies, with the cosmological constant appearing in the guise of the MOND acceleration constant, a0. But I am greatly gratified to see these propositions put forth, especially because they are made by people outside the traditional MOND community. It is very important that researchers from other backgrounds become interested in MOND and bring new ideas to further our understanding of its origin.

    And what if you had a unified theory of physics that explains everything? What then?

    You know, I’m not a religious person, but I often think about our tiny blue dot, and the painstaking work we physicists do here. Who knows? Perhaps somewhere out there, in one of those galaxies I spent my life researching, there already is a known unified theory of physics, with a variation of MOND built into it. But then I think: So what? We still had fun doing the math. We still had the thrill of trying to wrap our heads around the universe, even if the universe never noticed it at all.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Welcome to Nautilus. We are delighted you joined us. We are here to tell you about science and its endless connections to our lives. Each month we choose a single topic. And each Thursday we publish a new chapter on that topic online. Each issue combines the sciences, culture and philosophy into a single story told by the world’s leading thinkers and writers. We follow the story wherever it leads us. Read our essays, investigative reports, and blogs. Fiction, too. Take in our games, videos, and graphic stories. Stop in for a minute, or an hour. Nautilus lets science spill over its usual borders. We are science, connected.

     
  • richardmitnick 2:48 pm on February 18, 2017 Permalink | Reply
    Tags: , , Nautilus,   

    From Nautilus: “Dark Matter May Show Quantum Effects on a Galactic Scale” 

    Nautilus

    Nautilus

    2.18.17
    David “Doddy” Marsh

    This weird type of dark matter would also puff up galaxies and make stars age prematurely.

    1
    Microwave cavity in the ADMX axion detection experiment at the University of Washington. Credit: ADMX.

    U Washington ADMX
    U Washington ADMX

    An axion is a theoretical particle named after a laundry detergent. As particles go, it is a strange one. Its mass is tiny—somewhere between one trillionth the mass of the proton and one billion-trillion-trillionth. It is so lightweight, in fact, that it doesn’t even behave as a particle, but as a wave that could straddle a galaxy. It is also feeble—its influence extends over an almost absurdly short distance, a millionth of what the Large Hadron Collider is able to discern. These short distances stem from the possible relation between axions and very high energy physics, possibly even quantum gravity.

    When I first heard of the axion, I had no idea it would become my life’s work. I was a new grad student looking for a starter project, and I came across a paper with such a peculiar title that I couldn’t help but read it: “String Axiverse.” It was written by a group of people including John March-Russell, a theoretical physicist in my department at Oxford. Speaking to John and cosmologist Pedro Ferreira (who both later became my Ph.D. advisors), I realized that the axion was just what I wanted to work on: a fascinating theoretical construct, but with direct connection to the exciting modern progress in cosmology.

    An unknown particle that may exist in profusion: the axion is an ideal candidate for dark matter. But it is a very different beast than we’re used to thinking about, requiring us to go about the search for dark matter in a different way.

    The Nobelist Frank Wilczek gave the axion its name because it cleaned up a problem in the Standard Model of particle physics. In the 1970s, he and others puzzled over a mismatch between the two forces that govern atomic nuclei: the strong and weak nuclear forces. The strong force has a symmetry in its workings that the weak lacks, even though, a priori, there is no reason it should. Helen Quinn and Robert Peccei proposed that the force is not innately symmetrical, but develops this symmetry under the action of a new field akin to the Higgs field. The axion particle is a remnant of this field.

    To play its role, the axion must be extremely lightweight. For our current theories, that is awkward, because it creates an enormous gulf between this particle and all the others. But the low mass is entirely natural in string theory, our leading candidate for a unified theory of nature. String theory predicts there is not just one type of axion, but there are typically 30 or more different kinds, and it predicts that their masses are spread out over a wide range. Some therefore must be lightweight. String theory is often criticized for not making testable predictions, but that’s not quite right, because the theory does predict axions. Although I wouldn’t claim that discovering lots of axions would be evidence for string theory, I think it is fairly safe to say that, according to almost any theory other than string theory, it would be surprising if we discovered large numbers of them.

    ______________________________________________________________________
    If axion dark matter exists, it is completely invisible to a conventional experiment.
    ______________________________________________________________________

    Axions are like other candidates for dark matter in that they are dark—they have no electric charge and therefore do not emit or absorb light—and interact very weakly with ordinary matter. But there the resemblance stops. Compare it to the most commonly discussed type of dark matter, the WIMP, or weakly interacting massive particle.

    It is a so-called thermal relic, which, according to theory, is produced the same way as protons, neutrons, and atomic nuclei: from the collisions between particles in the hot, dense, early universe. Given the amount of missing mass that astronomers infer, this production mechanism for WIMPs sets their mass and interaction strength: 100 times the mass of the proton (hence “massive”) with an interaction strength roughly equal to the weak nuclear force (hence “weakly interacting”). These would be lumbering particles, and that is just what astronomers need to explain the distribution of galaxies. If they exist, we should be able to detect them in particle detectors similar to those we use to detect neutrinos, and we should even be able to produce them ourselves by mimicking those hot, dense conditions in the Large Hadron Collider.

    CERN/LHC Map
    CERN LHC Grand Tunnel
    CERN LHC particles
    LHC at CERN

    Axions, in contrast, have a different origin story. Their production is determined not by the temperature of the plasma in the early universe, but gravitationally, by the expansion of space in the big bang. This production mechanism sets their mass and interaction strength, which are vastly different from those of WIMPs.

    Big Bang to today
    Big Bang to today. http://www.sun.org/encyclopedia/a-short-history-of-the-universe

    Axions would interact with ordinary matter to a limited degree, but only by a unique set of interactions. For this reason, if axion dark matter exists, it is completely invisible to a conventional experiment such a WIMP detector or even the Large Hadron Collider.

    The poster-child axion direct-detection experiment is ADMX, which operates at the University of Washington and relies on a concept invented by Pierre Sikivie in 1983. Though “dark”, axions do interact with electromagnetism in other ways and, in the presence of a magnetic field, can metamorphose into photons or vice versa. ADMX attempts to perform the metamorphosis inside a microwave radio-frequency cavity like those used in radar equipment and microwave relay stations. So far ADMX have observed nothing, but it is sensitive only to axions whose wavelengths are comparable to the size of the cavity, and it has still not completed its full search program. Proposed experiments such as MADMAX and CASPEr would probe a much wider range of wavelengths.

    In principle, axions might have shown up in experiments intended for other purposes. With colleagues at the University of Sussex, the Swiss Federal Institute of Technology, and the University of New South Wales, as well as two talented grad students, Nicholas Ayres and Michał Rawlik, I have been digging through the archives of the nEDM experiment, which ran for a number of years at the Institut Laue-Langevin in France and is now at the Paul Scherrer Institute in Switzerland. It has been measuring neutrons, which would oscillate in a particular way if a galactic axion wave happened to pass through it, and we are reanalyzing the data to look for this signal.

    ______________________________________________________________________________________

    In this field, there’s room for young theorists such as me to make headway.
    ______________________________________________________________________________________

    If axions exist, stars would produce them naturally. Some of the photons produced during nuclear fusion in the core could metamorphose into axions, and they would escape the star more readily than photons do. This would drain the star of energy and cause it to age faster. Astronomers have been combing through star clusters for stars that look older than they actually are, and they have found no evidence of extra cooling. This null result sets limits on how strongly axions can interact with the constituents of stars.

    With my colleagues Dan Grin and Renée Hložek, I have also been searching for axions in cosmological data. Their wavelike properties might give them away. Over distances smaller than the axion wavelength, multiple axion waves would overlap and interfere with one another, causing them to exert an outward pressure and puff up galaxies. And indeed astronomers do find that galaxies are less clumpy than WIMPs should cause them to be (although there are many possible explanations for this, not just axions). My colleagues and I have been exploring this idea further by combining galaxy data with cosmic microwave background radiation measurements, as well as conducting simulations of galaxy formation with axion dark matter.

    Finally, axions would alter what happened during cosmic inflation, the primeval period when the universe was expanding at a breakneck rate. Cosmologists generally think the inflationary process created a torrent of gravitational waves, but if dark matter is made of axions, it would have generated very few. So, the discovery of primordial gravitational waves could be taken as falsification of the axion idea, at least in a wide range of models. (If we ever detected both axion dark matter and these gravitational waves, then something would be wrong with standard inflationary theory.)

    Only a small band of devotees have given much thought to axions. That makes it a fun field to be working in. There’s room for young theorists such as me to make headway and feel like we’re adding to the understanding of the community, which is much harder to do in a more mature field such studying WIMPs.

    It should be said that there is room in the universe for both axions and WIMPs. Both have a firm grounding in fundamental physics and in cosmology, and both may exist out there. For me, one of the benefits of thinking about axions is that they force to think beyond WIMPs. If all we ever do is study and simulate WIMPs because it is relatively easy, as a community we run the risk of confirmation bias, where WIMPs always come up trumps because they are all we know. Thankfully, that doesn’t seem to be how the field of dark-matter research is going. People are exploring a huge range. Dark matter is out there and discovering it is just a matter of time. When we do discover it, whatever it is, it will revolutionize our ideas of particle physics and cosmology.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Welcome to Nautilus. We are delighted you joined us. We are here to tell you about science and its endless connections to our lives. Each month we choose a single topic. And each Thursday we publish a new chapter on that topic online. Each issue combines the sciences, culture and philosophy into a single story told by the world’s leading thinkers and writers. We follow the story wherever it leads us. Read our essays, investigative reports, and blogs. Fiction, too. Take in our games, videos, and graphic stories. Stop in for a minute, or an hour. Nautilus lets science spill over its usual borders. We are science, connected.

     
  • richardmitnick 12:33 pm on December 11, 2016 Permalink | Reply
    Tags: Alfred Einstein, Ernst Mach, , Michele Besso, Nautilus,   

    From Nautilus: “When Einstein Tilted at Windmills” 

    Nautilus

    Nautilus

    December 1, 2016
    By Amanda Gefter

    1
    Illustrations by Jasu Hu

    The young physicist’s quest to prove the theories of Ernst Mach.

    When they met, Einstein wasn’t Einstein yet. He was just Albert Einstein, a kid, about 17, with a dark cloud of teenage angst and a violin. Michele Besso was older, 23, but a kindred spirit. Growing up in Trieste, Italy he had shown an impressive knack for mathematics, but he was kicked out of high school for insubordination and had to go live with his uncle in Rome.

    2

    Einstein could relate. At the Swiss Polytechnic, where he was now a student, his professors resented his intellectual arrogance, and had begun locking him out of the library out of spite.

    Their first encounter was on a Saturday night in Zurich, 1896. They were at Selina Caprotti’s house by the lake for one of her music parties. Einstein was handsome—dark hair, moustache, soulful brown eyes. Besso was short with narrow, pointed features and a thick pile of coarse black hair on his head and chin. Einstein had a look of cool detachment. Besso had the look of a nervous mystic. As they chatted, Einstein learned that Besso worked at an electrical machinery factory; Besso learned that Einstein was studying physics. Perhaps they recognized something in each other then: They both wanted to get to the truth of things.

    Besso would go on to become a sidekick, of sorts, to Einstein—a sounding board, as Einstein put it, “the best in Europe,” asking the right questions that would inspire Einstein to find the right answers. At times, though, he would seem to be something more—a collaborator, perhaps, making suggestions, working through calculations.

    At other times he’d be the perfect fool—a schlemiel, Einstein called him. Like the time Besso was sent on a job to inspect some newly installed power lines on the outskirts of Milan but missed his train and then forgot to go the following day. On the third day he finally made it to his destination, but by that time he’d completely forgotten what he was supposed to be doing there in the first place. He sent a postcard to his boss: “Instructions should be wired.”

    If Besso never seemed to know quite what he was doing, it wasn’t for a lack of smarts. “The great strength of Besso resides in his intelligence,” Einstein would write, “which is out of the ordinary, and in his endless devotion to both his moral and professional obligations; his weakness is his truly insufficient spirit of decision. This explains why his successes in life do not match up with his brilliant aptitudes and with his extraordinary scientific and technical knowledge.”

    Still other times, Besso would play the role of Einstein’s conscience—urging him to work things out with his future wife, Mileva, or to be a better father to his sons. Besso took care of those sons on Einstein’s behalf when Mileva was sick. “Nobody else is so close to me, nobody knows me so well,” Einstein would write in 1918.

    But there was something uncanny about Besso. Over the coming years, he would always show up at exactly the right moment, the perfect deus ex machina, handing Einstein books, innocently offering suggestions, prodding him, goading him, nudging him onto the right path, as if he had a plan. “I … watch my friend Einstein struggle with the great Unknown,” he would write, “the work and torment of a giant, of which I am the witness—a pygmy witness—but a pygmy witness endowed with clairvoyance.”

    That Saturday night, though, all of that lay in the future. For now, they became fast friends—best friends, really. They talked for hours on end. For his first act of camaraderie, Besso handed Einstein two books, insisting that he read them. They were the works of Ernst Mach, the final actor in this three-man play.

    Perhaps you’ve heard of Ernst Mach. Mach 1, Mach 2, Mach 3, that Mach.

    3
    Ernst Mach

    His name is a unit of speed, and—despite his beard—a brand of razors. He was a physicist, a physiologist, a philosopher. A little bit of everything, really. You could find the young Mach in the Austrian countryside carefully observing nature—staring at a leaf or a shadow or a cloud with the utmost concentration and scrutiny, then scrutinizing his scrutinizing, noting his every sensory glitch and glimmer, building a taxonomy of tricks that our eyes can play. He collected bugs and butterflies. He tested the reactions of various materials—in trying to see whether camphor would ignite, he burned off his eyelashes and eyebrows. But it was when he was 15 years old that a single moment changed everything.

    “On a bright summer day in the open air, the world with my ego suddenly appeared to me as one coherent mass of sensations,” he later wrote. He felt, in that moment, there was no reality sitting “out there,” independent of his sensations, and likewise that there was no self sitting “in here,” independent of its sensations. He grew certain that there could be no real difference between mind and matter, between perceiving subject and perceived object. “This moment was decisive for my whole view,” he wrote.

    From that day forward, he vehemently rejected any form of dualism: the idea that the external world was made up of substantial material objects—things—while the mind was made of something else, so that the world we experience in consciousness is a mere copy of an actual world that lies forever hidden from us. Instead he grew convinced that mind and matter were made of the same basic ingredient. It couldn’t be a physical ingredient, he argued, because how would bare matter ever give rise to subjective experience? But it couldn’t be a mental ingredient either, he said, because he was certain that the self was equally an illusion. The only way to unite mind and matter, he decided, was to presume that they were made not of objective atoms, and not of subjective qualia, but of some neutral thing, an “element,” he called it, which in one configuration would behave as material substance and in another as immaterial mentation, though in itself it would be neither and nothing.

    “There is no rift between the psychical and the physical, no inside and outside, no “sensation” to which an external “thing,” different from sensation, corresponds,” he wrote. “There is but one kind of elements, out of which this supposed inside and outside are formed—elements which are themselves inside or outside, according to the aspect in which, for the time being, they are viewed.” These elements “form the real, immediate, and ultimate foundation.”

    Mach’s view—neutral monism, it would later be called—required that every single aspect of reality, from physical objects to subjective sensations, be purely relational, so that whether something was “mind” or “matter” was determined solely by its relations with other elements and not by anything inherent to itself. It was a radical idea, but it seemed plausible. After all, Mach said, science is based on measurement, but “the concept of measurement is a concept of relation.” What we call length or weight, for instance, is really the relation between an object and a ruler, or an object and a scale.

    It dawned on Mach, then, that if we could rewrite science solely in terms of what can measured, then the world could be rendered entirely relational—entirely relative—and the mind and universe could be unified at last. But that was going to require a new kind of physics.

    By 1904, Don Quixote had become one of Einstein’s favorite books.

    Two years earlier, an unemployed Einstein had put an ad in the newspaper offering physics tutoring for three francs an hour, and a philosophy student named Maurice Solovine had shown up at his door. They started talking about physics and philosophy and didn’t stop; the whole tutoring thing never even came up. Soon Conrad Habicht, a mathematics student, joined the conversation, and the three young bohemians formed something of a book club for highbrowed degenerates. They read works of philosophy and literature and discussed them, sometimes until one in the morning, smoking, eating cheap food, getting rowdy and waking the neighbors. They met several nights a week. In mockery of stuffy academia, they dubbed themselves the Olympia Academy.

    Besso was in Trieste working as an engineering consultant, but he came when he could, and as Einstein’s closest friend, he was made an honorary member of the Academy. Under Besso’s influence, the Olympians read and discussed Mach. Eventually Einstein landed a job at the Patent Office in Bern, and in 1904 he got Besso a job in the same office, so they could work side by side. In the evenings, the Academy read Don Quixote. It struck a chord with Einstein—later, when his sister Maja lay dying, he would read it to her. As for the Olympia boys, who can say whether they noticed it then: how Besso had become the Sancho Panza to Einstein’s Quixote. When Solovine and Habicht left, it was just Einstein and Besso, walking home together from the patent office, discussing the nature of space and time and, as always, Mach.

    Mach’s plan to unite matter and mind required that every last bit of world be rendered relative, with nothing left over. But there was one stubborn obstacle standing in the way: According to physics, all motion was defined relative to absolute space, but absolute space wasn’t defined relative to anything. It just existed, self-defined, like the basement level of reality—it wouldn’t budge. Mach knew of this obstacle, and it rankled. He criticized Newton’s “conceptual monstrosity of absolute space”—the idea of space as a thing unto itself. But how to get around it?

    For years it had been bugging Einstein that all attempts on an observer’s part to determine whether or not he was at rest relative to absolute space were doomed to fail. For every experiment he could think of, nature seemed to have a clever trick up its sleeve to hide any evidence of absolute motion. It was so downright conspiratorial that one might suspect, as Einstein did, that absolute space simply didn’t exist.

    Following Mach’s lead, Einstein wanted to assert that motion was not defined by reference to absolute space, but only relative to other motion. Unfortunately, the laws of physics seemed to suggest otherwise. The laws of electromagnetism, in particular, insisted that light had to travel at 186,000 miles per second regardless of the observer’s frame of reference. But if all motion was relative, the light’s motion would have to be relative too—traveling 186,000 miles per second in one reference frame and some other speed in another, in blatant violation of electromagnetic law.

    So Einstein went to see Besso. “Today I come here to battle against that problem with you,” he announced when he arrived.

    They discussed the situation from every angle. Einstein was ready to give up, but they hammered away.

    The next day, Einstein returned. “Thank you,” he said. “I’ve completely solved the problem.” Within five weeks, his Theory of Special Relativity was complete.

    What magic words had Besso uttered in that fateful conversation? It seems he reminded Einstein of Mach’s central idea: a measurement is always a relation.

    Einstein and Besso discussed this—what two quantities we compare in order to measure time. “All our judgments in which time plays a part are always judgments of simultaneous events,” Einstein realized. “If, for instance, I say, ‘That train arrives here at 7 o’clock,’ I mean something like this: ‘The pointing of the small hand of my watch to 7 and the arrival of the train are simultaneous events.”

    But how does one know that two events are simultaneous? Perhaps you’re standing still and you see two distant lights flash at precisely the same moment. They’re simultaneous. But what if you had been moving? If you happened to be moving in the direction of flash A and away from flash B, you’d see A happen first, because B’s light would take ever so slightly longer to reach you.

    Simultaneity is not absolute. There’s no single “now” in which all observers live. Time is relative. Space, too.

    It all dawned on Einstein then: It was possible for all observers to see light moving at exactly 186,000 miles per second regardless of their own state of motion. The light’s speed is a measure of how much distance it covers in a given amount of time. But time changes depending on your state of motion. So even if you’re moving relative to the light, time itself will slow down precisely long enough for you to measure light’s speed at the very one required by Maxwell’s equations.

    Einstein’s 1905 paper On the Electrodynamics of Moving Bodies introduced the world to the theory of relativity, in which time and space can slow and stretch to account for an observer’s relative motions. It included no references whatsoever, but it ended with this final paragraph: “In conclusion I wish to say that in working at the problem here dealt with I have had the loyal assistance of my friend and colleague M. Besso, and that I am indebted to him for several valuable suggestions.”

    Einstein proudly sent his work to Mach, and seemed almost giddy when Mach responded with his approval. “Your friendly letter gave me enormous pleasure,” Einstein replied. “I am very glad that you are pleased with the relativity theory … Thanking you again for your friendly letter, I remain, your student, A. Einstein.”

    Einstein had a long way to go, however, to see Mach’s vision through. The problem was that special relativity only relativized motion for observers moving at a constant speed. The question of accelerated observers—those who were changing speed or rotating—was far trickier. Within special relativity, there was no way to blame the force that comes with acceleration on relative motion. Absolute space lingered.

    In 1907, Einstein made a breakthrough. It was the happiest thought of his life, he would later say: In small regions of space, an observer would be unable to tell whether he was accelerating or at rest in a gravitational field. This suggested that it might be possible to do away with the absolute nature of acceleration—and with it absolute space—once and for all. Gravity, it seemed, was the secret ingredient that made all motion relative, just as Mach had wanted. And that gave a whole new meaning to the very nature of gravity: The path of an accelerated observer through spacetime traces a curve, so if acceleration was equivalent to gravity, then gravity was the curvature of spacetime. It would be some time before Einstein brought his General Theory of Relativity to fruition, but for now, he knew he was on the right track.

    Excited, Einstein wrote a letter to Mach informing him of his progress and the publication of his newest paper. A new theory of gravity was underway, he said, and as soon as he could prove it correct, “your inspired investigations into the foundations of mechanics … will receive a splendid confirmation.” In other words: I’ve done what you wanted. He published his theory of general relativity in 1915; the next year, Mach died.

    Einstein wrote a long and moving obituary, glowing with praise for Mach’s scientific vision, with its central point, as Einstein wrote, that “physics and psychology are to be distinguished from each other not by the objects they study but only by the manner of ordering and relating them.” He argued that Mach himself was close to coming up with the theory of relativity, and wrote, with palpable admiration and innocence, that Mach “helped me a lot, both directly and indirectly.”

    That, however, was the apogee of the kinship between Einstein and Mach’s philosophy. Einstein would eventually disavow the pure relativism of his mentor, and even to split from his Sancho. The rift begins with a most unlikely event: words from beyond the grave.

    In 1921, Mach’s book The Principles of Physical Optics was published posthumously, and contained a preface written by the author around 1913, shortly after Einstein had sent him the early paper on general relativity.

    “I am compelled in what may be my last opportunity, to cancel my views of the relativity theory,” Mach wrote. “I gather from the publications which have reached me, and especially from my correspondence, that I am gradually becoming regarded as the forerunner of relativity … I must as assuredly disclaim to be a forerunner of the relativists …”

    Mach had likely seen what Einstein would only later come to terms with—that the so-called general theory of relativity did not live up to its name. General relativity was an unprecedented intellectual feat—but it didn’t make everything relative, as Mach had dreamed. In the final version of the theory, the equivalence between acceleration and gravitation, which had seemed to make all motion relative, turned out to hold only for infinitesimally small regions of space. Patching together local regions into one big universe produced misalignments at their edges, like flat tiles on a round globe. The misalignments revealed the curvature of spacetime—a global geometry that couldn’t be transformed away by a mere change in perspective. Each local region—a self-consistent, relative world—turned out to be the tiny tip of an enormous, four-dimensional iceberg, forever hidden from sight and decidedly not relative.

    It must have been an unsettling feeling for Einstein—watching his theory gather steam and speed away from him, proving the very thing he had set out to disprove. The problem was that, according to the theory, spacetime geometry was not fully determined by the distribution of matter in the universe, so that even if you removed everything observable, some extra ingredient still remained—spacetime itself, dynamic yet absolute. It created an unbridgeable divide between the physical world and the mind, inviting, in its realist stance, a whiff of pure belief, even mysticism—the belief in a four-dimensional substratum, the paper on which reality is drawn, though the paper itself is invisible.

    Einstein continued to push Mach’s view for several years after publishing general relativity in 1915, living in total denial of the fact that his own theory went against it. He tried everything under the sun to mold his theory into the shape of Mach’s philosophy—making the universe finite but unbounded, adding a cosmological constant—but it just wouldn’t fit. “The necessity to uphold [Mach’s principle] is by no means shared by all colleagues,” he said, “but I myself feel it is absolutely necessary to satisfy it.”

    So when Einstein first read Mach’s preface, it must have stung. We can hear his hurt in a comment he made at a lecture in Paris in 1922, shortly after Mach’s preface was published. Mach was un bon mecanicien, Einstein said bitterly, but a “deplorable philosophe.” He would no longer claim that his theory was one of Machian relativism, and by 1931 he would abandon Mach’s views completely. “The belief in an external world independent of the perceiving subject is the basis of all natural science,” he wrote. When asked how he could believe in anything beyond our sensory experience, he replied: “I cannot prove my conception is right, but that is my religion.” And in 1954, a year before his death: “We ought not to speak about the Machian Principle anymore.”

    What Mach had never known—couldn’t have known—was that his true devotee had never been Einstein. It was Besso.

    Besso, that pygmy witness endowed with clairvoyance, saw exactly where Einstein’s departure from Mach would soon lead him astray: in the realm of quantum mechanics.

    As Einstein came to grips with Mach’s rejection of relativity, the world of physics was rocked by quantum theory, a revolution Einstein had helped to spark but now refused to join. While he was making peace with an absolute spacetime—an absolute reality—quantum mechanics was rendering the world even more relative. The theory suggested that the outcomes of measurements could be defined only in relation to a given experiment: An electron might be a wave relative to one measuring apparatus and a particle relative to another, though in itself it was neither and nothing. In the words of Niels Bohr, the purpose of the theory was “to track down, so far as it is possible, relations between the manifold aspects of our experience”—relations and nothing more. In other words, quantum theory picked up Mach’s program right where Einstein left off, a point that both Bohr and Besso were quick to emphasize.

    When Einstein, complaining about a colleague’s work, joked to Besso that, “He rides Mach’s poor horse to exhaustion,” Besso replied, “As to Mach’s little horse, we should not insult it; did it not make possible the infernal journey through the relativities? And who knows—in the case of the nasty quanta, it may also carry Don Quixote de la Einsta through it all!”

    “I do not inveigh against Mach’s little horse,” Einstein responded, “but you know what I think about it. It cannot give birth to anything living.”

    The truth was, Einstein’s belief in a hidden reality had lain dormant for years, ever since he was a little boy—4, maybe 5—and his father had come to his bedside and handed him a compass. Einstein had held it in his hand, and found himself trembling in awe. The way the needle quivered, tugged northward by some invisible force, overwhelmed him with the feeling that “something deeply hidden had to be behind things.” Now he glimpsed it again in the mathematics of general relativity. With Mach’s approval moot, the awe he’d felt as a boy returned to him. When Besso tried to steer him away—toward Mach, toward the quantum— Einstein reproached his faithful squire: “It appears that you do not take the four-dimensionality of reality seriously.”

    The reinvention of Einstein as a young iconoclast who embraced Mach’s view and ran with it, determined to create a theory of pure relativity despite his natural realist leanings—was it actually Besso’s doing? Had the squire steered his master? In the short story “The Truth About Sancho Panza,” Franz Kafka suggests that this reversal is, in fact, the key to Cervantes’ tale. Don Quixote, he wrote, was Sancho Panza’s own creation, an alter ego invented to carry out some inner vision Panza himself was ill equipped to face. “I owe to you the scientific synthesis that without such a friendship one would never have acquired—at least, not without expending all one’s personal forces,” Besso wrote to Einstein—as if to say, thanks for working out that theory for me. But the synthesis was incomplete. Having guided Einstein to water, Besso appears to have failed to make him drink.

    Besso never gave up on luring Einstein back to Machian relativity. But Don Quixote had abandoned the knighthood for good, leaving Sancho to fend off the windmills for himself. In Princeton, New Jersey, his hair now white and wild, Einstein sat at a cluttered desk and struggled with reality while physics marched on without him. In Geneva, Switzerland, in the University mathematics library, his wiry beard now blanched with time, Besso sat hunched over his own pile of books, and worked—quietly, mysteriously—alone.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Welcome to Nautilus. We are delighted you joined us. We are here to tell you about science and its endless connections to our lives. Each month we choose a single topic. And each Thursday we publish a new chapter on that topic online. Each issue combines the sciences, culture and philosophy into a single story told by the world’s leading thinkers and writers. We follow the story wherever it leads us. Read our essays, investigative reports, and blogs. Fiction, too. Take in our games, videos, and graphic stories. Stop in for a minute, or an hour. Nautilus lets science spill over its usual borders. We are science, connected.

     
  • richardmitnick 8:14 am on October 6, 2016 Permalink | Reply
    Tags: Kate Marvel, Nautilus, ,   

    From Nautilus: Women in STEM – “The Parallel Universes of a Woman in Science” Kate Marvel 

    Nautilus

    Nautilus

    October 6, 2016
    Kate Marvel

    In physics and in life, choice and possibility play against each other.

    1
    Kaye Blegvad

    I spent years in graduate school where terrified students would desperately try to make small talk with Stephen Hawking in the corridors. There were few other women and no one else who was not brilliant, or at least capable of convincingly acting the part. When we walk by one professor he averts his eyes and, facing the wall, mutters fervently and kneads his sweaty palms. We assume he is religious. As it turns out, he is simply frightened of women.

    It is fortunate for him that there are so few of us. Another professor is reluctant to advise girls who will only get married and leave the field. Another refers to all women as Anna, what, in physics, we call a simplifying assumption. It doesn’t matter anyway.

    The women speak to the department chairman, a litany of small complaints: An elderly Fellow tried to kiss me. Someone grabbed me, I don’t know who, they all laughed about it. Do we belong here? He sits back and shakes his head and says, helplessly, what do you want me to do?

    In another universe we are terrifying and brazen, Amazons with steel breastplates. In this one, though, we are scared and tired and wary of wandering hands. The other girls are brilliant: They are required to be. I am stupid and 22 and in love with the famous young professor. He loves me too, until he doesn’t.

    The equations I study are like old friends to me; you can think of them as illustrations, maybe, or small, restful breaks between recognizable words. Here is one:

    3

    This is fairness in geometric form, the shape formed when everything is the same distance from the center. Mathematics liberates us from physical space. Increase n to add dimensions: point, line, circle, sphere. Go further: Embed curved hyperspheres in higher dimensional space. We can simplify complicated things, then complicate them further.

    But sometimes things are simple. Look closely enough at a curved surface and it appears flat. You move
    in straight lines down simple paths. Our everyday experiences are described by simple, familiar laws: inertia, force, reaction, f = ma.

    So I show up every day, unwanted but noticed. There are simple narratives for girls like me: tried, used, found wanting. I feel like a white rabbit after the snow retreats in early spring. There is a gentlemen’s agreement between us: Leave, and we will let you go. I graduate, barely, and go back to California. The sun shines, I am happy, and the universe goes on without me. Examined closely enough, everything is mundane.

    Nature abhors a vacuum; physicists love one. We have rich vocabularies to describe different flavors of emptiness. There are false vacuums, classically stable but subject to the strangeness of quantum mechanics. These are universes ever prone to decay. The rot proceeds by bubble: True vacuum nucleates inside the false one, making a sphere of baby universe. Inside the bubble the constants of nature take new values. The laws are the same inside and out, but followed differently. We create worlds inside worlds, let others fall away.

    Here is a fundamental law: We cannot go backward in time. And why would I? Sixteen, too skinny, angry at the world, and hoping not to be called to the board to solve equations. Refusing to learn times tables to 12. Dreams that do not require competence in basic algebra.

    But the world is not lacking in teenage aspiring actresses, and there is no shortage of prettier women hungry to play Wife, Girlfriend, Hot Girl 2. In drama class, we wait to be noticed. In astronomy class, we discuss the origin and fate of the universe. I can know more, if I am willing to learn to love the frightening grammar of equations. I have never felt stage fright, but math makes me nervous.

    Slowly, though, I learn quantum mechanics and particle physics and turn in problem sets at the last minute. My grades are C’s, then A’s, then top in the class. This is who I am now. I win a scholarship, a prestigious one, to graduate school. I stumble.

    It may be time for another equation:

    4

    It’s named after a dead white man, Austrian enough to merit an umlaut. Schrödinger’s equation: Is it a particle or a wave, neither or both? Psi is the wave function that exists everywhere and nowhere, in all possible universes and some impossible ones too. It takes no form and has no character until it is observed and forced to collapse into reality. There are many worlds and everything we know exists in them all.

    There are many universes in which my husband and I never meet, but it’s hard to think of one in which I love him as much as here. In some bubble universe, the worst one, his face merges with that of the young professor, so different from him, and they look in opposite directions like a god on a Roman coin. In this one he is kind, likes animals, and makes joyful art that no one wants to pay for.

    He comes with me when I leave graduate school. I take a job back home in California, and the shame and guilt at leaving physics dissipate like midday fog. I cling to the edges of science, dabbling in arms control, energy policy, network modeling, before finding work in the physics of climate change. There is something beautiful in the mess of air and water moving together and apart on a rotating sphere. There are useful and interesting problems to solve. There is a French woman in the office next door who is brilliant and friendly and pregnant with her second child, and we are all happy for her.

    We are not geniuses, although the kindly man in the office down the hall has a MacArthur grant. There is no Einstein or Feynman, just petabytes of data and rapidly melting ice caps. I make mistakes and say stupid things and am allowed second, third, fourth chances.

    After four years I start to forget the nasal whine of a hostile question and the blood sport of talks to aggressive audiences. I tell stories, funny ones, from grad school: the Fellow who ate only pickles, the night we got drunk and threw breadcrumbs at the Holbein portrait of Henry VIII. I laugh with my new colleagues and feel secure, protected, worth listening to. The sun streams through the double glazed windows onto the cheap gray-white desks and particleboard walls, and I believe I am happy.

    And then we get married, and my husband is offered his dream job.

    Here is Noether’s Theorem, named for the woman who discovered it:

    5

    It tells us that physics rests on symmetries: The sameness of a perfect sphere viewed from every vantage point means something fundamental is preserved on it. Conservation laws of energy, momentum, and charge all arise from fundamental symmetries of nature. It is tempting to impose moral dimensions on this: Invariance means fairness, fairness means the preservation of important things. Symmetries are beautiful. But they are not eternal.

    I stand on a hill between two identical valleys. Both possibilities are equally open to me so long as I remain undecided. Choice destroys this: Moving downward toward one valley means moving away from the other. Possibilities are closed. The symmetry is broken.

    When my husband is offered a position at an art college far away he does not hesitate. We go. I quit my job, pack the car, sweep the bougainvillea petals from the porch for the last time. New York City is a morass of garbage and sweating, hostile flesh. It feels strange, a different flavor of unhappiness. I talk to senior scientists, angling for a job, feeling awkward and uncomfortable. Anna, says the voice in my head, you got married and left. What a waste. What a shame.

    In another universe my anger expands, dark enough to counteract gravity. Planets are blown into dust. We choose to stay. Or we go, and the snow piles thrown up by the New York cars are dazzlingly white and sweet as spun marzipan. There is no winter. There are days where I don’t cry.

    There are worse things, of course, in this world and others. He deserves happiness, and has it. I find work eventually. I like my new colleagues. What does it matter that I feel precarious, awkward, always neglecting something important? Here, I am a wife, and I will do what my mother and grandmothers and all other wives do. He worries, fusses, is helpful around the house. What do you want me to do?

    I saved the best equation for last. It’s my favorite, probably everyone else’s too. Here it is:

    6

    These (and I’m afraid there are many of them contained in one elegant package) are the Einstein field equations, the core of general relativity. Force equals mass times acceleration, but mass itself is now situated in the universe, all universes, and warps space and time by its very existence. We can go backward in time to a singular point, where all symmetries are unbroken. We can determine the trajectories, pasts, and futures of objects, of planets, of this universe and others, almost exactly. Almost.

    Something accelerates the expansion of the universe, ripping space apart faster, again, than the speed of light. We name it and do not know what it is. We describe it, prosaically perhaps, as Dark Energy, and it is as mysterious as it is powerful. It feels wrong, a cheat that exists only in an equation. What do we understand it to be? Intrusive gravity, perhaps, from another universe, or the decayed remnants of someone else’s vacuum. It creates new horizons, new curtains beyond which we cannot see. It carries us further and further away from our neighbors, from each other, from what we know. We will never see each other again. We are never apart.

    See the full article here .

    Please help promote STEM in your local schools.

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    Welcome to Nautilus. We are delighted you joined us. We are here to tell you about science and its endless connections to our lives. Each month we choose a single topic. And each Thursday we publish a new chapter on that topic online. Each issue combines the sciences, culture and philosophy into a single story told by the world’s leading thinkers and writers. We follow the story wherever it leads us. Read our essays, investigative reports, and blogs. Fiction, too. Take in our games, videos, and graphic stories. Stop in for a minute, or an hour. Nautilus lets science spill over its usual borders. We are science, connected.

     
  • richardmitnick 8:50 am on September 1, 2016 Permalink | Reply
    Tags: , , , How Much More Can We Learn About the Universe?, , Nautilus,   

    From Nautilus: “How Much More Can We Learn About the Universe?” Lawrence M. Krauss 

    Nautilus

    Nautilus

    September 1, 2016
    Lawrence M. Krauss

    1
    Jackie Ferrentino

    As a cosmologist, some of the questions I hear most frequently after a lecture include: What lies beyond our universe? What is our universe expanding into? Will our universe expand forever? These are natural questions to ask. But there is an even deeper question at play here. Fundamentally what we really want to know is: Is there a boundary to our knowledge? Are there fundamental limits to science?

    The answer, of course, is that we don’t know in advance. We won’t know if there is a limit to knowledge unless we try to get past it. At the moment, we have no sign of one. We may be facing roadblocks, but those give every indication of being temporary. Some people say to me: “We will never know how the universe began.” “We can never know what happened before the Big Bang.” These statements demonstrate a remarkable conceit, by suggesting we can know in advance the locus of all those things that we cannot know. This is not only unsubstantiated, but the history of science so far has demonstrated no such limits. And in my own field, cosmology, our knowledge has increased in ways that no one foresaw even 50 years ago.

    2
    ON A CLEAR DAY YOU CAN’T SEE FOREVER: The farthest you see, in principle, is 45.3 billion light-years. Although that represents a direct limitation on our knowledge, it doesn’t keep us from grasping the basic workings of nature. NASA / Bill Ingalls

    his is not to say that nature doesn’t impose limits on what we can observe and how we can observe it. For example, the Heisenberg uncertainty principle constrains what we can know about the motion of a particle at any time, and the speed of light restricts how far we can see or travel in a given interval. But these limits merely tell us what we cannot observe, not what we cannot eventually learn. The uncertainty principle hasn’t gotten in the way of learning the rules of quantum mechanics, understanding the behavior of atoms, or discovering that so-called virtual particles, which we can never see directly, nevertheless exist.

    The observation that the universe is expanding does imply a beginning, because if we extrapolate backward, then at some point in the distant past, everything in our observable universe was co-located at a single point. At that instant, which now goes by the name of the Big Bang, the laws of physics as we know them break down, because general relativity, which describes gravity, cannot be successfully integrated with quantum mechanics, which describes physics on microscopic length scales. But most scientists do not view this as a fundamental boundary to knowledge, because we expect that general relativity will have to be modified as part of a consistent quantum theory. String theory is one of the major ongoing efforts to do so.

    Given such a theory, we might be able to answer the question of what, if anything, came before the Big Bang. The simplest possible answer is perhaps also the least satisfying. Both special and general relativity tie together space and time into a single entity: spacetime. If space was created in the Big Bang, then perhaps time was as well. In that case, there was no “before.” It simply wouldn’t be a good question. This is not the only possible answer, though, and we will need to await a quantum theory of gravity and its experimental confirmation before we will have any confidence in our reply.

    Then there is the question of whether we can know what lies beyond our own universe, spatially. What are the boundaries of our universe? Again, we can hazard a guess. If our spacetime arose spontaneously—which, as I argued at length in my last book, A Universe from Nothing, seems the most likely possibility—then it probably has zero total energy: The energy represented by matter is exactly offset by the energy represented by gravitational fields. Put simply, something can arise from nothing if the something amounts to nothing. Right now, the only universe that we can verify has zero total energy is a closed universe. Such a universe is finite yet unbounded. Just like you can move around the surface of a sphere forever without encountering any boundaries, the same may be true of our universe. If we look far enough in one direction, we would see the back of our heads.

    In practice, we cannot do that, probably because our visible universe is only part of a much larger volume. The reason has to do with something called inflation. Most universes that arise spontaneously with microscopic size will re-collapse in a microscopic time, rather than endure for billions of years. But, in some, empty space will be endowed with energy, and that will cause the universe to expand exponentially fast, at least for a brief period. We think that such a period of inflation occurred during the earliest moments of our Big Bang expansion and prevented the universe from re-collapsing immediately. In the process, the universe puffed up in size to become so great in extent that, for all intents and purposes, it would now appear flat and infinite—like a cornfield in Kansas that looks infinite despite being located on the huge sphere we call Earth. This is why we don’t see the backs of our heads when we look up in space, even though our universe may be closed on its largest scales. In principle, though, we could see the whole thing if we waited long enough, as long as inflation hadn’t resumed in our visible universe, and is not occurring elsewhere in regions of space we cannot observe.

    As for the possibility that regions we cannot yet observe, or may never observe, may be inflating, in fact our current theories suggest that this is the most likely possibility. If we consider the phrase “our universe” to refer to that region of space with which we once could have communicated or with which we one day may communicate, then inflation generally creates other universes beyond ours. Inflation may have been brief within our volume of space, but the rest of space expands exponentially forever, with isolated regions like ours occasionally decoupling from the expansion, just as isolated ice patches can form on the surface of fast-moving water when the temperature is below freezing. Each such universe had a beginning, pegged to the time when inflation ended within its spatial volume. In this case, the beginning of our universe may not have been the beginning of time itself—further reason to doubt whether the Big Bang represents an ultimate limit to our knowledge.

    3
    COLLIDING GALAXIES: Such cosmic commotion will one day cease to occur, and observers in the distant future may never realize how dynamic our universe once was. NASA

    Depending on the processes that cause each universe to decouple from the background space, the laws of physics might be different in each one. We have come to call this collection of possible universes a “multiverse.” The idea of a multiverse has gained traction in the scientific community not only because it is motivated by phenomena like inflation, but also because the possibility of many different universes, each with its own laws of physics, might explain various seemingly inexplicable fundamental parameters of our universe. Those parameters are simply the values that randomly arose when our universe was born.

    If other universes are out there, they are separated from ours by huge distances and recede at super-light relative velocities, so we can never detect them directly. Is the multiverse then just metaphysics? Does verifying the possible existence of a multiverse thus represent a fundamental boundary to our knowledge? The answer is: not necessarily. Although we may never see another universe directly, we can still test the theory that may have produced it empirically—for example, by observing gravitational waves that inflation would produce. This would allow us in principle to test the detailed nature of the inflationary process that resulted in our universe. These waves are similar to the gravitational waves recently discovered by LIGO, but differ in their origin. They come not from cataclysmic events such as the collisions of massive black holes in distant galaxies, but from the earliest moments of the Big Bang, during the putative period of inflation. If we can detect them directly—as we might be able to do in a variety of experiments that are now looking for the signature they would leave in the cosmic microwave background radiation left over from the Big Bang—we can probe the physics of inflation and then determine whether eternal inflation is a consequence of this physics. Thus, indirectly, we could test whether other universes must exist, even if we cannot detect them directly.

    In short, we have discovered that even the very deepest metaphysical questions—which previously we might have imagined would never be empirically addressable, including the possible existence of other universes—may in fact be accessible, if we are clever enough. No limits to what we may learn from the application of reason combined with experimental observation are yet known.

    A universe without limits is appealing and motivates us to continue searching. But can we be confident there will be no limits to our knowledge, ever? Not quite.

    Inflation does place a fundamental limit on knowledge—specifically, knowledge of the past. It essentially resets the universe, destroying potentially all the information about the dynamical processes that preceded it. The rapid expansion of space during inflation severely dilutes the contents of any region. So it may have wiped out traces of, for example, magnetic monopoles, a type of particle that theory suggests the very early universe produced in profusion. That was one of the original virtues of inflation: It reconciled the fact we have never seen such particles with predictions of their production. But in getting rid of a discrepancy, inflation erased aspects of our past.

    Worse, the erasure may not be over. We are apparently living in another period of inflation right now. Measurements of the recession of distant galaxies indicates that the expansion of our universe is currently speeding up, not slowing down, as it would be if the dominant gravitational energy resided in matter or radiation, and not in empty space. We currently have no understanding of the origin of this energy. Each of the potential explanations suggests fundamental limits to the progress of knowledge and even to our very existence.

    The energy of empty space could suddenly disappear if the universe undergoes some kind of phase transition, a cosmic version of steam condensing into liquid water. If that were to happen, the nature of fundamental forces might change, and all the structures we see in the universe, from atoms on up, might become unstable or disappear. We would disappear along with everything else.

    But even if the expansion continues, the future is still rather dismal. Within about 2 trillion years—which may seem like a long time on human scales, but is not so long on cosmic scales—the rest of the universe will disappear from our view. Any observers who evolve on planets around stars in this distant future will imagine that they live on a single galaxy surrounded by an eternal empty space, with no signs of acceleration or even any evidence of an earlier Big Bang. Just as we have lost sight of monopoles, they will be blind to the history that we readily see. (To be sure, they may have access to observable phenomenon we do not yet have access to, so we shouldn’t feel too superior.)

    Either way, we should enjoy our brief moment in the sun and learn what we can, while we can. Work harder, graduate students!

    See the full article here .

    Please help promote STEM in your local schools.

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    Welcome to Nautilus. We are delighted you joined us. We are here to tell you about science and its endless connections to our lives. Each month we choose a single topic. And each Thursday we publish a new chapter on that topic online. Each issue combines the sciences, culture and philosophy into a single story told by the world’s leading thinkers and writers. We follow the story wherever it leads us. Read our essays, investigative reports, and blogs. Fiction, too. Take in our games, videos, and graphic stories. Stop in for a minute, or an hour. Nautilus lets science spill over its usual borders. We are science, connected.

     
  • richardmitnick 10:06 am on August 7, 2016 Permalink | Reply
    Tags: , , Nautilus, We Should Not Accept Scientific Results That Have Not Been Repeated   

    From Nautilus: “We Should Not Accept Scientific Results That Have Not Been Repeated” 

    Nautilus

    Nautilus

    Jul 29, 2016
    Ahmed Alkhateeb

    1
    Photograph by Tony Buser / Flickr

    A few years ago, I became aware of serious problem in science: the irreproducibility crisis. A group of researchers at Amgen, an American pharmaceutical company, attempted to replicate 53 landmark cancer discoveries in close collaboration with the authors. Many of these papers were published in high-impact journals and came from prestigious academic institutions. To the surprise of everyone involved, they were able to replicate only six of those papers—approximately 11 percent.

    As expected, this observation had wide reverberations throughout the scientific community. The inability to independently replicate scientific findings threatens to undermine trust in the institution of science.

    Yet, as an experimental biologist, my initial reaction to this crisis was dismissive. I reaffirmed to myself that science is self-correcting, and that wrong ideas have a place within scientific discourse. After all, this is the very characteristic that distinguishes science from other human endeavors and gives it its nobility.

    But as it turns out, irreproducibility in itself was not the problem—rather, it was its extent, which is becoming more apparent due to the exponential rise in scientific output (over 1.1 million scientific papers were indexed in PubMed in 2015). Widespread irreproducibility is often misconceived as intentional fraud—which does occur, and is documented by websites like Retraction Watch. But the majority of irreproducible research stems from a complex matrix of statistical, technical, and psychological biases that are rampant within the scientific community.

    The institutionalization of science in the early decades of the 20th century created a scientific sub-culture, with its own reward systems, behaviors, and social norms. The rest of society sees this sphere a bit differently: Scientists are portrayed as selfless individuals who are solely motivated by curiosity and a hunger for knowledge. However, the existence of the irreproducibility crisis implies that other motives may also exist.

    The first question to ask, in addressing the problem of irreproducibility, is: Why do scientists do science? This question itself is the subject of an entire academic discipline. Sociologists of science have consistently identified “public recognition” as scientists’ primary motivating factor. Of course, other drivers do exist, such as puzzle solving, knowledge building, and financial gain. But recognition seems to represent the common, essential driver.

    Scientists’ behavior on an individual level is consistent with this view. We are obsessed with discovering things first, affiliating with prestigious institutions, publishing in recognized journals, getting cited by the masses, winning awards, and standing on stages. Scientists, like the rest of humanity, crave attention and respect by their peers and role models. The inability of scientists to admit this fact is understandable: The implication that their motives are self-serving can diminish the nobility of their work.

    The well-recognized sociologist Robert Merton has pointed out that scientists’ need for recognition may stem from their need to be assured that what they know is worth knowing, and that they are capable of original thought. In this view, recognition is necessary for intellectual confidence.

    The nature of scientific motivation is also evident in scientific reward systems. These rewards often come in some form of validation, such as awards, titles, and press coverage, which are then translated into career advancement and opportunities for greater prestige. Guidelines for promotion in several academic centers where I have worked have listed “Broader reputation than local area” as one of two promotion criteria for associate professors. In other words, the promotion of an assistant professor to an associate professor requires them to be famous within their field.

    Currently, publishing in prestigious journals and being extensively cited represent the height of recognition in the scientific community. These two metrics imply quality, but have long been proven to be hollow. Papers in high impact journals, for example, suffer from irreproducibility at almost the same rate as those in lower impact journals. And those high-profile papers that are retracted are cited considerably both before and after their retraction.

    The inconvenient truth is that scientists can achieve fame and advance their careers through accomplishments that do not prioritize the quality of their work. If recognition is not based on quality, then scientists will not modify their behaviors to select for it. In the culture of modern science, it is better to be wrong than to be second.

    This does not mean that quality is completely neglected. The Nobel Prize—the most coveted form of recognition—is associated with scientific discoveries of the highest caliber. But for the tens of thousands of scientists fighting over shrinking research budgets, winning less visible awards becomes an obsession, needed for promotions and grants.

    Today, the majority of the assessment metrics for quality in modern science is based on citations, such as impact factor and h-index. Conceptually, citations represent a good approximation of quality; however, they are greatly influenced by the sociological dynamics of the scientific community and can, thus, be gamed. For example, peer reviewers can ask authors to cite their papers as an implied condition for favorable critique. Also, journal editors encourage citation of relevant papers published in the same journal to drive up its impact factor. Interestingly, savvy scientists often add citations to their papers preemptively to appease potential reviewers and editors.

    The gaming of these metrics should not be viewed as merely a consequence of a flawed publishing model, but as a reflection of academic motives. So introducing new publishing platforms, or changes in the peer-review process—such as the innovations pioneered by F1000 and PLOS ONE—although very important and timely, may not lead to broad changes in behavior and thus may not improve reproducibility. That will only happen when outcomes become more closely aligned with the most coveted reward: recognition.

    To make the desire for recognition compatible with prioritizing good science, we need quality metrics that are independent of sociological norms. Above all, objective quality should be based on the concept of independent replication: A finding would not be accepted as true unless it is independently verified.

    Distinguishing between replicated and un-replicated studies would change how science is reported and discussed, increase the visibility of both strong and weak papers, incentivize scientists to only publish findings they have confidence in, and discourage publishing for the sake of publishing. Institutions would want to hire faculty with stellar qualitative records to build trust with industrial and governmental funders. Funding agencies would be inclined to support grants whose hypotheses are built on strong premises, and are submitted by investigators and institutions both known for quality. The public would become more skeptical of un-replicated science, preventing the wide adoption of false scientific ideas.

    Of course, the transition to an institutionalized process to assess replication-based quality will require structural changes. First, scientists would need to be incentivized to perform replication studies, through recognition and career advancement. Second, a database of replication studies would need to be curated by the scientific community. Third, mathematical derivations of replication-based metrics would need to be developed and tested. Fourth, the new metrics would need to be integrated into the scientific process without disrupting its flow.

    But these changes are all feasible and desirable. It is our responsibility as scientists to create transparency on how academic science is incentivized, produced, and evaluated. As Brian Nosek and colleagues from the Center of Open Science once said, “Openness is not needed because we [scientists] are untrustworthy; it is needed because we are human.”

    See the full article here .

    Please help promote STEM in your local schools.

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    Welcome to Nautilus. We are delighted you joined us. We are here to tell you about science and its endless connections to our lives. Each month we choose a single topic. And each Thursday we publish a new chapter on that topic online. Each issue combines the sciences, culture and philosophy into a single story told by the world’s leading thinkers and writers. We follow the story wherever it leads us. Read our essays, investigative reports, and blogs. Fiction, too. Take in our games, videos, and graphic stories. Stop in for a minute, or an hour. Nautilus lets science spill over its usual borders. We are science, connected.

     
  • richardmitnick 7:43 am on July 17, 2016 Permalink | Reply
    Tags: , Brian Eno, Music, Nautilus, ,   

    From Nautilus: “Brian Eno Plays the Universe” 

    Nautilus

    Nautilus

    July 7, 2016
    Stephon Alexander
    Illustration by Ric Carrasquillo

    1

    A physicist explains what the composer has in common with the dawn of the cosmos.

    Everyone had his or her favorite drink in hand. There were bubbles and deep reds, and the sound of ice clinking in cocktail glasses underlay the hum of contented chatter. Gracing the room were women with long hair and men dressed in black suits, with glints of gold necklaces and cuff links. But it was no Gatsby affair. It was the annual Imperial College quantum gravity cocktail hour. Like the other eager postdocs, this informal meeting was an opportunity to mingle with some of the top researchers in quantum gravity and hopefully ignite a collaboration, with a drink to sooth our nerves. But for me this party would provide a chance encounter that encouraged me to connect music with the physics of the early universe.

    The host was dressed down in black from head to toe—black turtleneck, jeans, and trench coat. On my first day as a postdoctoral student at Imperial College, I had spotted him at the end of a long hallway in the theoretical physics wing of Blackett Lab. With jet-black wild hair, beard, and glasses, he definitely stood out. I said, “Hi,” as he walked by, curious who he was, and with his “How’s it going?” response, I had him pegged. “You from New York?” I asked. He was.

    My new friend was Lee Smolin, one of the fathers of a theory known as loop quantum gravity, and he was in town considering a permanent job at Imperial. Along with string theory, loop quantum gravity is one of the most compelling approaches to unifying Einstein’s general relativity with quantum mechanics. As opposed to string theory, which says that the stuff in our universe is made up of fundamental vibrating strings, loop quantum gravity focuses on space itself as a woven network of loops of the same size as the strings in string theory.

    Lee had offered up his West Kensington flat for the quantum gravity drinks that evening to give the usual annual host, Faye Dowker, a break. Faye enjoyed being the guest lecturer that evening. Bespectacled, and brilliant, she was also a quantum gravity pioneer. While Professor Dowker was a postdoc she studied under Steven Hawking, working on wormholes and quantum cosmology, but her specialty transformed into causal set theory. After a couple of hours, the contented chatter gave way to Faye as she presented her usual crystal-clear exposition of causal sets as an alternate to strings and loops. Like loop quantum gravity, causal sets are less about the stuff in the universe and more about the structure of spacetime itself. But instead of being woven out of loops, spacetime is described by a discrete structure that is organized in a causal way. The causal-set approach envisions the structure of space analogous to sand on a beachhead. If we view the beachhead from afar, we see a uniform distribution of sand. But as we zoom in, we can discern the individual sand grains. In a causal set, spacetime, like a beach made up of sand, is composed of granular “atoms” of space-time.

    Scattered into the quantum gravity mixer were those working primarily on string theory, like the American theorist, Kellogg Stelle, who was a pioneer of p-branes, as well as one of my postdoc advisors. In mathematics, a membrane is a two-dimensional extended object—that is, it takes up space. A p-brane is a similar object in higher dimensions.

    The strings of string theory can collectively end on p-branes. And coming at quantum gravity from yet another route, there was Chris Isham, the philosophical topos theory man who played with mathematical entities that only “partially exist.” Postdocs studying all avenues of quantum gravity filled in the gaps between the big brains in the room. It wasn’t exactly a gathering of humble intellect. It was scenes like that, that made me feel like I didn’t have the chops, the focus, to sit behind a desk in a damp office manipulating mathematical symbols for hours like the others. Fortunately, Chris had shown he believed in my abilities to make a contribution to cosmology by encouraging me to get out of the office and get more involved with my music. Working on physics ideas and calculations in between sets, at the jazz dives of Camden town, I found myself trying hard to believe that it would give me a creative edge in my research. But something was about to change.

    While Faye gave her living-room lecture, I honed in on someone else I had noticed throughout the evening. Dressed in black like Lee, he had a strong face and a gold tooth that shone every time someone engaged him in conversation. The way he listened to Faye, with such focus, I assumed he was a hardcore Russian theorist. It turned out he had come with Lee. When Lee noticed I was still hanging around after the talk, he invited me to join them as Lee walked his gold-toothed friend back to his studio in Notting Hill Gate. I was curious what research this friend was going to churn up and what school of quantum gravity he’d slot into. I had to work to keep pace with the animated duo as we walked along well-lit high streets, dipping in and out of dark London mews. This guy was no regular physicist, I soon realized. Their conversation was unprecedented. It started with the structure of spacetime and the relativity of time and space according to Einstein. That wasn’t the strange part. Soon, they were throwing commentary around on the mathematics of waves and somehow kept coming back to music. This gold-toothed wonder was getting more intriguing by the minute.

    That was my first encounter with Brian Eno. Once we reached his studio, we exchanged phone numbers, and he generously lent me one of his bikes—indefinitely. At the time, I didn’t know who Brian was, but that changed a week later when I told a friend and band member about him. Tayeb, a gifted British-Algerian bassist and ooud player (an Arabic string instrument), was at first dumbfounded by my shameful ignorance. “Bloody hell, Stephon … you met the master.”

    Brian Eno, former member of the English rock band Roxy Music, established himself early on as a great innovator of music. He was part of the art rock and glam rock movement, when rock ‘n’ roll took on a new sound by incorporating classical and avant-garde influences. The rocker look was dressed up with flamboyant clothes, funky hair, and bright makeup: think Lou Reed, Iggy Pop, and David Bowie. Brian was the band’s synthesizer guru, with the power to program exquisite sounds. The beauty of synthesizers in those days lay in their complexity. In the early days, one had to program them—unlike synthesizers today, with preset sounds at the touch of a button. Popularity hit Roxy Music hard and fast, and Eno promptly had enough of it, so he left Roxy Music, and his career continued to flourish. He produced the Talking Heads and U2 and went on to collaborate with and produce greats such as Paul Simon, David Bowie, and Coldplay. In addition, he continued with synthesizers and emerged as the world’s leading programmer of the legendary Yamaha DX7 synthesizer.

    I wondered why an artist like Brian would be interested in matters of spacetime and relativity. The more I got to know Brian, I knew it wasn’t a time filler, or for his health. What I was about to discover during my two years in London was that Brian was something I’ve come to call a “sound cosmologist.” He was investigating the structure of the universe, not inspired by music, but with music.

    Often he would make a comment in passing that would even impact my research in cosmology. We began meeting up regularly at Brian’s studio in Notting Hill. It became a pit stop on my way to Imperial. We’d have a coffee and exchange ideas on cosmology and instrument design, or simply veg out and play some of Brian’s favorite Marvin Gaye and Fela Kuti songs. His studio became the birthplace of my most creative ideas. Afterward, I’d head to Imperial, head buzzing, spirits high, motivated to continue my work on calculations or discussions on research and publications with fellow theorists.

    One of the most memorable and influential moments in my physics research occurred one morning when I walked into Brian’s studio. Normally, Brian was working on the details of a new tune—getting his bass sorted out just right for a track, getting a line just slightly behind the beat. He was a pioneer of ambient music and a prolific installation artist.

    3

    Eno described his work in the liner notes for his record, Ambient 1: Music for Airports: “Ambient music must be able to accommodate many levels of listening attention without enforcing one in particular; it must be as ignorable as it is interesting.” What he sought was a music of tone and atmosphere, rather than music that demanded active listening. But creating an easy listening track is anything but easy, so he often had his head immersed in meticulous sound analysis.

    That particular morning, Brian was manipulating waveforms on his computer with an intimacy that made it feel as if he were speaking Wavalian, some native tongue of sound waves. What struck me was that Brian was playing with, arguably, the most fundamental concept in the universe—the physics of vibration. To quantum physicists, particles are described by the physics of vibration. And to quantum cosmologists, vibrations of fundamental entities such as strings could possibly be the key to the physics of the entire universe. The quantum scales those strings play are, unfortunately, terribly intangible, both mentally and physically, but there it was in front of me—sound—a tangible manifestation of vibration. This was by no means a new link I was making, but it made me start to think about its effect on my research and the question Robert Brandenberger had put to me: How did structure in our universe form?

    Sound is a vibration that pushes a medium, such as air or something solid, to create traveling waves of pressure. Different sounds create different vibrations, which in turn create different pressure waves. We can draw pictures of these waves, called waveforms. A key point in the physics of vibrations is that every wave has a measurable wavelength and height. With respect to sound, the wavelength dictates the pitch, high or low, and the height, or amplitude, describes the volume.

    If something is measurable, such as the length and height of waves, then you can give it a number. If you can put a number to something, then you can add more than one of them together, just by adding numbers together. And that’s what Brian was doing—adding up waveforms to get new ones. He was mixing simpler waveforms to make intricate sounds.

    To physicists, this notion of adding up waves is known as the Fourier transform. It’s an intuitive idea, clearly demonstrated by dropping stones in a pond. If you drop a stone in a pond, a circular wave of a definite frequency radiates from the point of contact. If you drop another stone nearby, a second circular wave radiates outward, and the waves from the two stones start to interfere with each other, creating a more complicated wave pattern. What is incredible about the Fourier idea is that any waveform can be constructed by adding waves of the simplest form together. These simple “pure waves” are ones that regularly repeat themselves.

    Linked by the physics of vibration, Brian Eno and I bonded. I began to view Fourier transforms in physics from the perspective of a musician mixing sound, seeing them as an avenue for creativity. The bicycle Brian lent me became the wheels necessary to get my brain from one place to another faster. For months, the power of interdisciplinary thought was my adrenaline. Music was no longer just an inspiration, not just a way to flex my neural pathways, it was absolutely and profoundly complementary to my research. I was enthralled by the idea of decoding what I saw as the Rosetta stone of vibration—there was the known language of how waves create sound and music, which Eno was clearly skilled with, and then there was the unclear vibrational message of the quantum behavior in the early universe and how it has created large-scale structures. Waves and vibration make up the common thread, but the challenge was to link them in order to draw a clearer picture of how structure is formed and, ultimately, us.

    Among the many projects Brian was working on at the time was one he called “generative music.” In 1994 Brian launched generative music to a studio full of baffled journalists and released the first generative software piece at the same time. The generative music idea that came to fruition about a decade later was an audible version of a moiré pattern. Recall our pond ripples interfering to create complex patterns. These are moiré patterns, created by overlapping identical repeating patterns, and there are an infinite variety of them. Instead of two pebbles creating waves, generative music rested on the idea of two beats, played back at different speeds. Allowed to play forward in time, simple beat inputs led to beautiful and impressive complexity—an unpredictable and endless landscape of audible patterns. It is “the idea that it’s possible to think of a system or a set of rules which once set in motion will create music for you … music you’ve never heard before.” Brian’s first experiment with moiré patterns was Discreet Music, which was released in 1975. It remains a big part of his longer ambient compositions such as Lux, a studio album released in 2012. Music becomes uncontrolled, unrepeatable, and unpredictable, very unlike classical music. The issue becomes which inputs you choose. What beats? What sounds?

    What I began to see was a close link between the physics underlying the first moments of the cosmos—how an empty featureless universe matured to have the rich structures that we see today—and Brian’s generative music. When I walked up to him one morning as he was manipulating the waveforms, he looked at me with a smile and said, “You see, Stephon, I’m trying to design a simple system that will generate an entire composition when activated.”

    A light bulb flickered in my brain. I began to seriously consider the hypothesis that the infant universe was not featureless, and its original radiation energy resonated like simple sound waves, much like Brian’s FM synthesizer. In this sense, our universe behaved like the ultimate generative music composition. The initial vibration of the energy fields sonified throughout the spacetime background like the vibrating body of an instrument, generating the first structure in our cosmos and then the first stars and eventually us.

    See the full article here .

    2
    By Stephon Alexander

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Welcome to Nautilus. We are delighted you joined us. We are here to tell you about science and its endless connections to our lives. Each month we choose a single topic. And each Thursday we publish a new chapter on that topic online. Each issue combines the sciences, culture and philosophy into a single story told by the world’s leading thinkers and writers. We follow the story wherever it leads us. Read our essays, investigative reports, and blogs. Fiction, too. Take in our games, videos, and graphic stories. Stop in for a minute, or an hour. Nautilus lets science spill over its usual borders. We are science, connected.

     
  • richardmitnick 9:26 am on July 14, 2016 Permalink | Reply
    Tags: , , Nautilus, , Quakefinder   

    From Nautilus: “The Last of the Earthquake Predictors” 

    Nautilus

    Nautilus

    July 14, 2016
    Mark Harris
    Illustration Daniel Savage

    In late winter of 1975, a seismologist named Cao Xianqing tracked a series of small earthquakes near Haicheng, China, which he took to presage a much larger one to come. On the morning of February 3, officials ordered evacuations of the surrounding communities. Despite the subfreezing weather, many residents abandoned their homes, although others refused, dismissing the warning as another cry of “wolf” in a string of false alarms.

    Yet this time, around dinnertime the very next day, Cao’s prognosis materialized in the form of a massive, magnitude 7.3 quake. Bridges collapsed, pipes ruptured, and buildings crumbled. But the accurate early alert—the first ever documented—spared thousands of lives: Of the 150,000 casualties predicted for a disaster of comparable size, only about 25,000 were tallied, including just over 2,000 deaths.

    1
    Two major earthquakes occurred 17 months apart in the mid-1970s near the cities of Haicheng and Tangshan in northern China. (Illustration by Jack Cook, WHOI Graphic Services)

    2
    SHAKE DOWN: Northern China experienced a high frequency of earthquakes in the 1960s and ’70s, including the famous Haicheng quake and Tangschan quake. U.S. Geological Survey

    The successful forecast of the Haicheng quake seemed to justify the optimism felt by earthquake researchers around the world, who believed they were on the brink of unlocking the secrets of Earth’s tectonic motion. Just a few years earlier, in 1971, geophysicist Don Anderson, who headed the California Institute of Technology’s renowned Seismology Laboratory, had boasted that prediction science would soon pay big dividends. With enough funds, he told a local reporter, “it would in my opinion be possible to forecast a quake in a given area within a week.”

    Those funds duly arrived. In 1978, the United States Geological Survey (USGS) allocated over half its research budget ($15.76 million) to earthquake prediction, a level of spending that continued for much of the next decade. Scientists deployed hundreds of seismometers and other sensors, hoping to observe telltale signals heralding the arrival of the next big one. They looked for these signs in subterranean fluids, crustal deformations, radon gas emissions, electric currents, even animal behavior. But every avenue they explored led to a dead end.

    “In our long search for signals, we never saw anything that could be used in a reliable way,” says Ruth Harris, a geophysicist at the USGS. “Either the method wasn’t repeatable or it looked like the original thing was just a case of noise.” Even the famous Haicheng prediction turned out to be little more than fabulously good luck. Cao later admitted he had based his warning partly on foreshocks, which precede some large quakes by minutes to days, and mostly on superstition. According to a book he’d read called Serendipitous Historical Records of Yingchuan, the heavy autumn rains of 1974 would “surely be followed” by a winter earthquake.

    Since the early 20th century, scientists have known that large quakes often cluster in time and space: 99 percent of them occur along well-mapped boundaries between plates in Earth’s crust and, in geological time, repeat almost like clockwork. But after decades of failed experiments, most seismologists came to believe that forecasting earthquakes in human time—on the scale of dropping the kids off at school or planning a vacation—was about as scientific as astrology. By the early 1990s, prediction research had disappeared as a line item in the USGS’s budget. “We got burned enough back in the 70s and 80s that nobody wants to be too optimistic about the possibility now,” says Terry Tullis, a career seismologist and chair of the National Earthquake Prediction Evaluation Council (NEPEC), which advises the USGS.

    Defying the skeptics, however, a small cadre of researchers have held onto the faith that, with the right detectors and computational tools, it will be possible to predict earthquakes with the same precision and confidence we do just about any other extreme natural event, including floods, hurricanes, and tornadoes. The USGS may have simply given up too soon. After all, the believers point out, advances in sensor design and data analysis could allow for the detection of subtle precursors that seismologists working a few decades ago might have missed.

    And the stakes couldn’t be higher. The three biggest natural disasters in human history, measured in dollars and cents, have all been earthquakes, and there’s a good chance the next one will be too. According to the USGS, a magnitude 7.8 quake along Southern California’s volatile San Andreas fault would result in 1,800 deaths and a clean-up bill of more than $210 billion—tens of billions of dollars more than the cost of Hurricane Katrina and the Deepwater Horizon oil spill combined.

    At a time when American companies and institutions are bankrolling “moonshot” projects like self-driving cars, space tourism, and genomics, few problems may be as important—and as neglected—as earthquake prediction.

    3
    Earth and fire: Piton de la Fournaise, on the French island of La Reunion, erupts in October 2010. Weeks before, volcanologists detected decreases in the speed of ambient noise waves traveling through the ground below, suggesting a new tool for predicting geological events. IMAZ PRESS/Gamma-Rapho via Getty Images

    David Schaff was a senior at Northwestern University when a magnitude 6.7 earthquake struck the upscale Los Angeles suburb of Northridge in January 1994. A devout Christian, Schaff saw a connection between the time the quake began (4:31 pm) and verse 4:31 in Acts of the Apostles, a book of the New Testament: “After they prayed, the place where they were meeting was shaken.”

    “I was amazed that God would have complete control of the timing and location of something as chaotic, energetic, and unpredictable as an earthquake,” says Schaff, now a professor at Columbia University. He believed the Northridge quake was a divine message. “I thought, as a scientist who was a believer, He might use me to help warn people of impending earthquakes.”

    After graduation, Schaff enrolled at Stanford University to pursue a Ph.D. in geophysics. “I was learning about earthquakes from my academic advisors and from my pastor in my church,” he says. His faith told him that “earthquakes serve many purposes, and one is to create awe and wonder and amazement in God—and also fear.” But he didn’t doubt they also had a physical origin.

    As Schaff’s textbooks laid out, the dozen or so tectonic plates that make up Earth’s crust are always on the move, continuously slipping past or sliding over each other. They creep as fast as a few inches a year, deforming the rock at the seams until it can no longer withstand the strain. Then, in one sudden and violent motion, all that tension is released. The rock snaps apart, shifting the earth as much as several feet in a matter of seconds.

    This “elastic rebound” generates two types of seismic waves. The fastest waves, and thus the first to hit nearby communities or infrastructure, are high-frequency body waves, which travel through Earth’s interior. Body waves come in two flavors: Primary “P” waves push and pull the ground as they race outward like sound through air, while secondary “S” waves rattle the rock up and down. The effects of these waves are typically so subtle that, although some animals can sense them, humans notice only a quick jolt or vibrations—or nothing at all. Virtually all of the damage caused by earthquakes is due to slower, low-frequency surface waves: Love waves, which wobble things side to side, and Rayleigh waves, which roll like breakers in the deep ocean, toppling power lines and lifting buildings off their foundations.

    The vast majority of shaking that seismometers detect on a daily basis, however, has nothing to do with earthquakes. In fact, the earth is constantly awash in ambient noise—extremely low-amplitude Love and Rayleigh waves produced by road and rail traffic, industrial activity, and natural movements like wind. Ocean waves are a major source of this background rumbling: Striking the continental margin, they generate gentle reverberations that can propagate thousands of miles. Schaff’s advisors taught him to discard ambient noise, which they sometimes cursed for masking geological signals.

    But in 2001, as Schaff was beginning a post-doctoral fellowship at Columbia, physicists at the University of Illinois published a paper showing that ambient noise had a secret utility: By correlating measurements from distant receivers, one could estimate how fast ambient waves propagated, and thus determine the composition of the material the waves had traveled through.[1] Indeed, in a 2005 study in the journal Science, a team led by seismologist Nikolai Shapiro, then at the University of Colorado at Boulder, used ambient-noise recordings to map the ground beneath Southern California.[2] Unusually slow waves, the team discovered, corresponded to sedimentary basins, while unusually fast waves indicated the igneous cores of mountains.

    Scientists quickly realized that ambient noise could similarly provide a means to observe geologic turmoil brewing deep underground. In 2010, in the weeks before two consecutive eruptions of Piton de la Fournaise, a volcano on the French island of La Reunion, in the Indian Ocean, volcanologist Anne Obermann and her colleagues at the Swiss Seismological Service detected decreases in the velocity of ambient waves passing through the earth below.[3] Their discovery bolstered a controversial theory called dilatancy, which posits that cracks opening up in stressed subterranean rock will cause it to expand. This gradual dilation slows any seismic waves traveling through, possibly warning that the rock is nearing its breaking point.

    4
    Sensing Shaking: The USGS earthquake monitoring network at Parksfield includes a wide array of instruments, including geodimeters (top), GPS sensors (bottom left), and portable electronic distance measuring devices (bottom right). USGS

    First proposed in the 1970s, dilatancy seemed to explain Soviet scientists’ apparent progress in predicting major earthquakes by tracking speed changes in S and P waves from minor quakes and other seismic activity. But when this approach was later discredited, dilatancy fell into disrepute.

    In light of Obermann’s findings, Schaff, who had since become an associate professor, wondered whether the theory might have a kernel of truth. If one could measure shifts in the velocity of ambient waves preceding volcanic eruptions, maybe it was possible to detect similar shifts before large earthquakes. There was already a hint that it was. In a 2008 Nature paper, seismologists led by Fenglin Niu, at Rice University, in Texas, reported the slowing of seismic waves hours before two small quakes in the tiny farming community of Parkfield, California.[4]

    Niu, however, had created his own noise. Using a buried piezoelectric transmitter, which converts electrical energy to motion, he had sent surface waves to a recorder a few meters away. Replicating this set-up on a practical scale, along the lengths of entire faults, would be ruinously expensive.

    “The beauty of ambient noise is that it’s free,” Schaff says. In 2010, he began mining archival noise data from a network of USGS seismometers near Parkfield—a site long seen, ironically, as a monument to the folly of earthquake prediction.

    ituated slap bang on top of the San Andreas fault separating the North American and Pacific Plates, Parkfield experienced an earthquake of magnitude 6.0 or greater about once every 22 years between 1857 and 1966. In 1985, the USGS confidently announced that the next one would occur before 1993. In anticipation, researchers blanketed the area with instruments, including seismometers, strain gauges, dilatometers, magnetometers, and GPS sensors.

    But it wasn’t until 2004 that another biggish one, a magnitude 6.0 quake, finally hit. And if the decades-long wait weren’t bad enough, the sensor results were worse. “Prior to the 2004 earthquake, the scores of instruments at Parkfield … recorded nothing out of the ordinary,” reports seismologist Susan Elizabeth Hough in her book Predicting the Unpredictable. “The fault did not start to creep in advance of the earthquake. The crust did not start to warp; no unusual magnetic signals were recorded. The earthquake wasn’t even preceded by the large foreshock scientists were expecting.”

    Schaff, however, wondered if faint precursors of the 2004 quake might be hiding in ambient noise, where the USGS hadn’t thought to look. “One man’s signal is another man’s noise,” he says.

    5
    AT FAULT: A crack snakes through a family homestead during the long-awaited magnitude 6.0 earthquake in Parksfield, California in 2004. The USGS had predicted the quake would arrive by 1993. Spencer Weiner/Los Angeles Times via Getty Images

    To get a clear speed reading of ambient waves, scientists typically must average data over periods as long as a month, making it hard to pinpoint precisely when a change occurred. But because Parkfield had such a high density of seismometers—13 within 20 kilometers of the quake’s epicenter—Schaff was able to get the resolution down to a single day. His calculations showed that ambient waves had slowed during the quake itself, then gradually sped up as the earth settled into a new shape. But try as he could, Schaff couldn’t tease out any significant speed changes in the days leading up to the main event.[5]

    “The conclusion for this particular earthquake was that, if there was a change, it was too small, too short, or might not have occurred in the area we were sampling,” he says. “It would be worth designing experiments with more stations to monitor areas where we suspect there might be an earthquake.” Schaff isn’t the only researcher who thinks this. At least a few dozen independent scientists in the U.S. and abroad have devoted their careers—and sometimes their own bank accounts—to the hunt for predictive signals, scrutinizing not just ambient noise but also thermal radiation and electromagnetic fields.

    Tom Bleier, a former satellite engineer living about a thousand feet from the San Andreas fault, near Silicon Valley, operates a network of magnetometers called QuakeFinder.

    6

    He got interested in earthquake precursors more than two decades ago, intrigued by scientists’ reporting of strange electromagnetic fluctuations days before a magnitude 6.9 quake struck Loma Prieta, south of San Francisco, in 1989. With $2 million from NASA, QuakeFinder has since expanded from a handful of DIY sensors to a global network of 165 stations, most of them installed along faults in California, including San Andreas, Hayward, and San Jacinto.

    So far, QuakeFinder has captured data for seven medium to large earthquakes (greater than magnitude 5.0). In the weeks prior to several of them, Bleier says, the data show distinctive electromagnetic pulses between 0.1 and 10 nanotesla in size, as much as 100,000 times weaker than Earth’s natural field. It’s possible, he points out, that these faint blips occurred before all seven quakes, but in some cases were drowned out by other magnetic disturbances, such as from lightning, solar storms, or even passing cars.

    6
    7
    A major breakthrough came in 2007, when an M5.4 earthquake occurred very close to a QuakeFinder instrument located at East Milpitas, California (2 Km). Reviewing the data recorded before the date of the quake, October 30, 2007, researchers discovered a distinct pattern of ultra-low frequency magnetic pulses starting two weeks before the quake, and disappearing after the event. Quakefinder.

    Friedemann Freund, a physicist associated with the SETI Institute who has also attracted NASA funding, has a theory about what might be causing all this pulsing. Days before an earthquake, he believes, stressed underground rock generates large electric currents, which migrate to the surface, perturbing Earth’s magnetic field while simultaneously ionizing the air and emitting a burst of infrared energy. (At Freund’s advice, each of QuakeFinder’s $50,000 magnetometer stations also includes ion sensors.)

    Most seismologists are highly sceptical of Freund’s theory. “NASA really likes to fund things that are a leap into the unknown,” says John Vidale, a professor of earth and space science at the University of Washington and the state’s official seismologist. “But there are leaps into the unknown and leaps into things that we know are not likely to work out. There’s no reason why what Freund is saying couldn’t be right. It’s just extremely unlikely that it is.”

    Even Bleier concedes that QuakeFinder isn’t ready to publish its predictions just yet. “We wouldn’t go off and issue public forecasts without being under the guidance of USGS,” he says. Even in the throes of optimism, it’s important to be cautious. “You can imagine a scenario where you feel there’s going to be an earthquake in San Francisco, and you issue a public forecast, and the city empties out—and no earthquake happens.”

    There’s no need to imagine. In the late 1970s, Brian Brady, a geophysicist with the U.S. Bureau of Mines believed he had found a mathematical model that could predict earthquakes by analyzing stresses along a fault. He warned that a series of rumblings culminating in a gargantuan, magnitude 9.9 quake would strike Lima, Peru in 1981. But when the alleged start date rolled around, Lima was nothing more than a perfectly intact ghost town.

    Eight years later, in 1989, a self-taught climatologist named Iben Browning made a similar blunder when he proclaimed, based on tidal observations, that several earthquakes would rattle New Madrid, Missouri on Dec. 3, 1990. Schools closed, emergency services geared up for disaster, and locals fled. But no quake ever came.

    It’s no wonder, Schaff says, that funders such as the USGS and the National Science Foundation (NSF) are now gun shy about anything that smacks of prediction. “They view this research as high-reward but also high-risk. Budgets are tight. The NSF did fund one of my projects, but the second one they didn’t.” Bleier, too, is scrambling to keep QuakeFinder going and expand its reach. “We’d love to do a network up in the Pacific Northwest, where they’re really concerned about a major earthquake and tsunami, but we just don’t have the money,” he says.

    Most mainstream seismologists, however, aren’t interested in a moonshot. “Personally, I don’t think we’ll ever be able to say ‘There will be a magnitude 7.0 earthquake at this minute in this place’,” says the USGS’s Harris. “The earth is just so complicated. Putting a lot of money into understanding subduction zones and the mechanics of faults—and retrofitting buildings—would be great. But just putting money into earthquake prediction wouldn’t be worth it.”

    The NEPEC’s Tullis agrees. “We don’t know enough,” he says. Even so, he admits, he’s willing to hold out hope that, like any deliberate venture into the unknown, the slow grind of seismology might eventually yield a breakthrough no one was expecting. “Over time, with enough measurements and careful analysis, maybe at some point, someone will stumble across something that has definitive predictive value, ” he says, and then, perhaps wary of sounding too sanguine, quickly adds a caveat: “It will certainly have to be proven, assuming it’s even possible. It will need an awful lot of testing.”

    Schaff, meanwhile, is putting his confidence in a power higher than the USGS. “After 22 years of study,” he says, “I have come to the conclusion that it is impossible for mankind to predict earthquakes without God giving insight into the secrets and mysteries of their occurrence.”

    References

    1. Lobkis, O.I. & Weaver, R.L. On the emergence of the Green’s function in the correlations of a diffuse field. The Journal of the Acoustical Society of America 110, 3011-3017 (2001).

    2. Shapiro, N.M., Campillo, M., Stehly, L., & Ritzwoller, M.H. High-resolution surface-wave tomography from ambient seismic noise. Science 307, 1615-1618 (2005).

    3. Obermann, A., Planès, T., Larose, E., & Campillo, M. Imaging preeruptive and coeruptive structural and mechanical changes of a volcano with ambient seismic noise. Journal of Geophysical Research 118, 6285-6294 (2013).

    4. Niu, F., Silver, P.G., Daley, T.M., Cheng, X., & Majer, E.L. Preseismic velocity changes observed from active source monitoring at the Parkfield SAFOD drill site. Nature 454, 204-208 (2008).

    5. Schaff, D.P. Placing an upper bound on preseismic velocity changes measured by ambient noise monitoring for the 2004 Mw 6.0 Parkfield earthquake (California). Bulletin of the Seismological Society of America 102, 1400-1416 (2012).

    See the full article here .

    Meet The Quake-Catcher Network

    QCN bloc

    Quake-Catcher Network

    The Quake-Catcher Network is a collaborative initiative for developing the world’s largest, low-cost strong-motion seismic network by utilizing sensors in and attached to internet-connected computers. With your help, the Quake-Catcher Network can provide better understanding of earthquakes, give early warning to schools, emergency response systems, and others. The Quake-Catcher Network also provides educational software designed to help teach about earthquakes and earthquake hazards.

    After almost eight years at Stanford, and a year at CalTech, the QCN project is moving to the University of Southern California Dept. of Earth Sciences. QCN will be sponsored by the Incorporated Research Institutions for Seismology (IRIS) and the Southern California Earthquake Center (SCEC).

    The Quake-Catcher Network is a distributed computing network that links volunteer hosted computers into a real-time motion sensing network. QCN is one of many scientific computing projects that runs on the world-renowned distributed computing platform Berkeley Open Infrastructure for Network Computing (BOINC).

    BOINCLarge

    BOINC WallPaper

    The volunteer computers monitor vibrational sensors called MEMS accelerometers, and digitally transmit “triggers” to QCN’s servers whenever strong new motions are observed. QCN’s servers sift through these signals, and determine which ones represent earthquakes, and which ones represent cultural noise (like doors slamming, or trucks driving by).

    There are two categories of sensors used by QCN: 1) internal mobile device sensors, and 2) external USB sensors.

    Mobile Devices: MEMS sensors are often included in laptops, games, cell phones, and other electronic devices for hardware protection, navigation, and game control. When these devices are still and connected to QCN, QCN software monitors the internal accelerometer for strong new shaking. Unfortunately, these devices are rarely secured to the floor, so they may bounce around when a large earthquake occurs. While this is less than ideal for characterizing the regional ground shaking, many such sensors can still provide useful information about earthquake locations and magnitudes.

    USB Sensors: MEMS sensors can be mounted to the floor and connected to a desktop computer via a USB cable. These sensors have several advantages over mobile device sensors. 1) By mounting them to the floor, they measure more reliable shaking than mobile devices. 2) These sensors typically have lower noise and better resolution of 3D motion. 3) Desktops are often left on and do not move. 4) The USB sensor is physically removed from the game, phone, or laptop, so human interaction with the device doesn’t reduce the sensors’ performance. 5) USB sensors can be aligned to North, so we know what direction the horizontal “X” and “Y” axes correspond to.

    If you are a science teacher at a K-12 school, please apply for a free USB sensor and accompanying QCN software. QCN has been able to purchase sensors to donate to schools in need. If you are interested in donating to the program or requesting a sensor, click here.

    BOINC is a leader in the field(s) of Distributed Computing, Grid Computing and Citizen Cyberscience.BOINC is more properly the Berkeley Open Infrastructure for Network Computing, developed at UC Berkeley.

    Earthquake safety is a responsibility shared by billions worldwide. The Quake-Catcher Network (QCN) provides software so that individuals can join together to improve earthquake monitoring, earthquake awareness, and the science of earthquakes. The Quake-Catcher Network (QCN) links existing networked laptops and desktops in hopes to form the worlds largest strong-motion seismic network.

    Below, the QCN Quake Catcher Network map
    QCN Quake Catcher Network map

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Welcome to Nautilus. We are delighted you joined us. We are here to tell you about science and its endless connections to our lives. Each month we choose a single topic. And each Thursday we publish a new chapter on that topic online. Each issue combines the sciences, culture and philosophy into a single story told by the world’s leading thinkers and writers. We follow the story wherever it leads us. Read our essays, investigative reports, and blogs. Fiction, too. Take in our games, videos, and graphic stories. Stop in for a minute, or an hour. Nautilus lets science spill over its usual borders. We are science, connected.

     
  • richardmitnick 9:15 am on June 23, 2016 Permalink | Reply
    Tags: , Nautilus,   

    From Nautilus: “The Lessons of a Ghost Planet” 

    Nautilus

    Nautilus

    June 23, 2016
    Thomas Levenson

    Vulcan shows us science beyond the scientific method.

    Sometime between November 11 and 18, 1915, Albert Einstein began a brief calculation. In 14 numbered steps he analyzed the orbit of Mercury to explain a minor anomaly that had defied astronomers for more than 50 years.

    Sorting out a tiny detail of celestial mechanics doesn’t seem terribly exciting—and yet Einstein reported to friends that when he saw the last numbers appear, confirming that his theory matched observation, he felt his heart literally shudder in his chest. The reason: Correctly analyzing the orbit of Mercury was the first confirmation of his account of gravity, the General Theory of Relativity. This is just as Richard Feynman would later say science works. It is, he would say, “a special method of finding things out.” But what makes it special? The way its answers get confirmed or denied: “Observation is the judge”—the only judge as the catechism goes—“of whether something is so or not.” [1]

    This is what every beginning scientist learns to call the scientific method, which goes pretty much as this online guide puts it: You “Construct a Hypothesis” to “Test with an Experiment” (or an observation), and then you “Analyze Results” and “Draw Conclusions.” If the results don’t match your expectation, it’s back to step one.

    Laid out like that, the scientific method becomes an intellectual extruder: data in one end, knowledge out the other. There’s only one problem: Science—even when it’s Albert Einstein at the controls—doesn’t work like that.

    To see why, consider those who worked on Mercury before Einstein solved the problem. Urbain Jean-Joseph Le Verrier was the greatest mathematical astronomer of the mid-19th century. In 1846, he discovered Neptune “at the tip of his pen”—using Newton’s law of gravity to predict the existence of an unseen body, whose gravitational tug on Uranus could account for wobbles in the known planet’s orbit. Nine years later, he analyzed Mercury’s motion and found another anomaly—a tiny shift in its orbit that couldn’t be explained by Venus or Jupiter or any other object in the solar system. Using the same logic that had led him to Neptune, Le Verrier again predicted the existence of an unseen planet very close to the sun. That hypothetical object swiftly gained a name: Vulcan.

    1
    No image caption. No image credit.

    The chain of reasoning was impeccable—and apparently confirmed when the first reports of Vulcan sightings arrived, just months after the prediction. Le Verrier himself validated the very first claim—and even though none of the dozen or more “discoveries” announced over the next two decades were replicated, he remained convinced of the reality of Vulcan until his death.

    The last person to be certain he’d actually seen Vulcan was famed asteroid hunter James Craig Watson, director of the Michigan Observatory. Viewing a total eclipse of the sun in 1878, Watson saw very close to the limb of the sun “a ruddy star whose magnitude I estimated to be 4 ½”—just where Vulcan ought to have been.

    Two years later Watson died, like Le Verrier going to his grave convinced that he’d found a new planet. Both men were good scientists, Le Verrier legitimately a great one. Le Verrier performed enormously difficult calculations that applied Newton’s theory to the fine-grained structure of reality. The logic behind his prediction of Vulcan was impeccable. His identification of the anomaly in Mercury’s orbit was and remains correct: Mercury orbit really does wobble, just as he said it did.

    Watson did what Feynman said should be done: Put theory to the test of direct observation of nature. But here the simple picture of the scientific method as a perfect machine for making knowledge breaks down: Neither man accepted the verdict nature tried to render. The case for Vulcan was too strong—it seemed—for mere observation to wreck such a beautiful idea. They wanted to believe, and they did, to the end.

    Why? Because, simply and unsurprisingly, scientists, like any human, both think and feel. They are subject to desire, ambition, pleasure in perceived beauty. In the long run—as when Einstein finally offered a new idea to replace Newton’s, and thus explained away the anomaly that seemed to demand Vulcan—science truly is self-correcting. Day by day, though, human hopes and expectations constrain what any single scientist can bring him or herself to accept—and that’s not an indictment of either the individual or the enterprise. Rather, it is how imperfect humans collectively (and fitfully) achieve a progressively more accurate grasp of the material world.

    That’s true even for the greatest scientists, and it holds even when what seems like a breakthrough really is one. In the cartoon version of the scientific method, Einstein’s pursuit of gravity should have begun from the realization that Mercury’s misbehavior suggested a problem with Newton’s gravitation. But that’s not what happened. Instead, Einstein noticed a contradiction between his first great result, the special theory of relativity, and Newton’s ideas. It was that conflict of ideas, and not some confounding observation, that led him to the ultimate prize.

    Vulcan in the 21st century is just another of the uncounted plausible ideas that didn’t work—and it’s mostly forgotten, along with those who championed it. General relativity stands as one of the greatest individual accomplishments in the history of science. And yet, Le Verrier and Watson each thrilled at the appearance of Vulcan in their mathematics and their telescope; Einstein’s heart leapt as he realized that he had just captured a piece of nature no one before him had seen. There’s no method in such moments. But there is a lot of science—as scientists live it.

    Reference

    1. Feynman, R. The Meaning of It All, Basic Books, New York, NY (1998).

    See the full article here .

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