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  • richardmitnick 2:35 pm on June 1, 2017 Permalink | Reply
    Tags: , , , , Forbes, OSU The big Ear, ,   

    From Forbes: “Astronomers Still Can’t Rule Out SETI’s ‘Wow!’ Signal” 

    ForbesMag

    Forbes Magazine

    May 31, 2017
    Bruce Dorminey

    Nearly four decades after it was received, astronomers still can’t say with 100% certainty that the ‘Wow!’ signal was not an interstellar radio beacon from some far-flung extraterrestrial civilization. But the signal — which got the Wow! moniker after an astronomer first scribbled those letters in the margins of the incoming data — was never reacquired.

    Even so, Bob Dixon, Ohio State University’s (SETI) Search for Extraterrestrial Intelligence program director at the time, once told me that the signal had to have at least originated at distance beyond the Moon.

    1
    The Milky Way and the constellation of Sagittarius. Credit: Terrence Dickinson via NASA

    What is known is that the signal was received just after 11 PM local time on August 15, 1977, at OSU’s now defunct Big Ear Radio Observatory.

    Ohio State Big Ear Radio Telescope

    Its position on the sky came from the direction of the star cluster M55 in the constellation of Sagittarius. Yet more importantly, it closely-matched the narrow emission line of hydrogen at 1420 megahertz , a radio-quiet spot long touted as a potential interstellar hailing frequency for E.T. civilizations. And at the time, it was also the strongest such SETI (Search for Extraterrestrial Intelligence) candidate signal ever seen.

    “So, ‘Wow!’ was appropriate,” Dan Werthimer, chief scientist at the University of California at Berkeley’s SETI program, told me.

    SETI@home, BOINC project at UC Berkeley Space Science Lab


    But he says it would be more convincing if the signal had appeared one after another along the Big Ear’s two different radio observing beams.

    That, says Werthimer, would be more of an indication that it was an artificial radio beacon from an interstellar point source. But we occasionally see Radio Frequency Interference (RFI) that’s modulated in just the right way that makes it look like it is consistent with a distant point source, says Werthimer. But as he emphasizes, if the signal were really from E.T. and was in the telescope’s observing sights for at least a few minutes, the source of the signal should have moved from one beam into the other.

    “It didn’t,” said Werthimer. “So, I’m 99% confident that the signal the OSU guys saw was RFI.”

    Still, there’s another possibility and that is that the signal did originate from beyond the moon, but was produced by two active comets orbiting within our solar system. That is, within the vicinity of the ‘Wow!’ signal’s position on the sky.

    A 2015 paper published by The Washington Academy of Sciences proposed that during that summer of 1977, comets 266P/Christensen and P/2008 Y2 (Gibbs) “were transiting in the neighborhood of the Chi Sagittarii star group” and produced by a large hydrogen cloud around their nucleus. Because the frequency for the ‘Wow!’ signal fell close to the radio emission for hydrogen, the paper noted that these local cometary hydrogen clouds would be strong candidates as the signal’s source.

    The comet hypothesis sounds somewhat plausible, but I still don’t buy it. If this cometary phenomena were at all statistically frequent, researchers would likely have picked up something similar over the last 50 years. And to my knowledge, this is the first time that anyone has argued that such narrowband emission is from a comet.

    My personal best guess is that the signal was not RFI. But more likely, it was the product of some very distant or unusual and/or poorly-understood astrophysical phenomenon.

    2
    Credit: Wikipedia

    That’s not to say that E.T. isn’t out there somewhere. But the likelihood that we would only receive a lone radio beacon, that’s never repeated and could never be reacquired, also seems implausible.

    Most people can live with the fact that there may be no one out there. Some prefer the notion that we are the ultimate undiscovered country in a cosmos teeming with intelligent life. But few like the idea that we narrowly missed E.T.’s one-off phone call.

    Werthimer, however, says either the ‘Wow!’ signal’s rise and fall in strength was actually intrinsic to the signal, in which case he says it would have to be RFI. Or if the signal were from a distant source, he says, then it would be constant in power and its rise and fall in strength would be due to Earth’s rotation.

    The remote possibility that it’s the real thing is what makes the ‘Wow!’ signal so haunting . You can dismiss it as Radio Frequency Interference (RFI) until the cows come home. But as Werthimer himself reluctantly acknowledged: “We can’t rule out E.T.”

    See the full article here .

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  • richardmitnick 8:27 am on February 23, 2017 Permalink | Reply
    Tags: , , , Forbes   

    From Forbes: “9 Tips For Communicating Science To People Who Are Not Scientists” 

    [Very important for my readers. I have over 800 readers between the blog, the Facebook Fan page, and Twitter. I assume that many of them are non-specialist readers. I hope that I am accomodating them. That is one reason I emphasize graphics. It is also why I try to always include links to any science papers so that people can get an actual look at the science even if they are not scientists.]

    ForbesMag

    Forbes Magazine

    Nov 22, 2016
    Marshall Shepherd

    1
    U.S. Secretary of State John Kerry, right, listens to scientist John Stone about the increased movement of icebergs across Antarctica at the Crary Science and Engineering Center, McMurdo Station in Antarctica Saturday, Nov. 12, 2016. (Mark Ralston/Pool Photo via AP)

    1. Know your audience. Many scientists are guilty of delivering the same message to the Rotary Club or Congressional Staffers that they give at a science conference. Research and understand your audience. Anthony Leiserowitz, an excellent climate communication scholar at Yale, once told me, “Not knowing your audience is like throwing darts at a dartboard with the lights off.”

    2. Don’t use jargon. Scientists throw terms like “bias,” “positive trend,” and”pdf” around easily. While most scientists associate “probability density function” with “pdf,” I bet the first thing that many in the public think about is a file format or attachment. Richard Sommerville and Susan Hassol provide a nice table of other jargony science terms to be cautious of in a Physics Today article.

    3. Get to the point. As scientists we are trained to describe a ton of details and background information before we give the final results. This is the very nature of how graduate students are trained to write their theses and dissertations. It is how scientists deliver presentations at conferences. For the public or policymakers this approach basically needs to be flipped. The key points or findings need to be delivered very early (see below) and it needs to be concise (think elevator speech).

    2
    Styles of communication. Source: AAAS

    4. Use analogies and metaphors. I find that analogies to real life work well. Though not perfect, when I use “weather is your mood, climate is your personality” or “if you don’t like the weather wait a few hours, if you don’t like the climate move” they resonate with people as a way to distinguish weather from climate. It also helps them to understand how silly it sounds when someone makes a statement about climate change based on today’s weather.

    5. Three points. Studies continue to show that three key points are effective with audiences.

    Consider the Venue: Are you speaking at a science café, or planning a social media strategy? Reach out to the point of contact or organizer for information and to ask questions about the attendees. When you schedule an interview with a reporter, ask them about the story and what kind of information they are looking for.

    Conduct an Internet Search: What type of events has the organization held in the past? Read or watch some stories the journalist wrote or produced to determine their perspective on the topic. On social media, review content produced or shared by members of your target audience in the past.

    On the Spot: For in-person engagements, take some time beforehand to meet audience members. During an event, you can take a quick poll of the audience by asking for a show of hands, to get a sense of prior experience or interest.

    I often notice this seems to be difficult for scientists (remember I am a scientist) because they tend to want to tell the entire story and with every detail. Scientists need to work hard to keep their message memorable, meaningful and miniature. These are the so-called “Three M’s of Messaging” that the American Association for the Advancement of Science (AAAS) has also recommended in its Science Communications workshops.

    6. You are the expert. Often scientists must speak with the media and for many this uncomfortable. The key points to remember: (a) Be confident because you are the expert, (b) Don’t speculate or stretch if you don’t know (say so), and (c) Reflect on what you want (or do not want) on the record days, months or years later and use that as a filter.

    7. Use social media. Social media can be tricky but is a “net” good for science communication as long as you are able to deal with the very high noise to signal ratio, dissenting thoughts (whether expert or not), limits on messaging and time management. I cringe when I hear a scientist or scholar say they shy away from social media. Newsflash: It is not new. It is not just for the kids. It is an important medium that policymakers, media and other scholars follow.

    8. The myth of “popularizers.” Some within the academy can be a bit uppity and elitist at times. They turn their nose up at scholars that choose to take their message beyond journals, conferences and classrooms. More than ever I find that thinking to be a kind of “head in the sand” model. More than ever the expertise of scholars is needed in broader venues otherwise “non-experts” or “agendas” will gladly fill the void. In today’s world it is possible to achieve “scholarly” metrics while having a broader impact.

    9. Relate. As much as we understand the current and future challenges associated with our changing climate it is a struggle for many in the public to see beyond kitchen table issues affecting their families. The reality is that they are there but it is not always obvious. The science communicator must keep this in mind and find ways to relate the message to the core values of the person or audience. For some that may be economics, faith, defense or curiosity.

    Dr. Marshall Shepherd, Dir., Atmospheric Sciences Program/GA Athletic Assoc. Distinguished Professor (Univ of Georgia), Host, Weather Channel’s Sunday Talk Show, Weather (Wx) Geeks, 2013 AMS President

    See the full article here .

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  • richardmitnick 11:58 am on December 12, 2016 Permalink | Reply
    Tags: , , , Forbes   

    From Forbes: “9 Tips For Communicating Science To People Who Are Not Scientists” 

    ForbesMag

    Forbes Magazine

    Nov 22, 2016 [Just appeared in social media.]
    Marshall Shepherd

    Many of the most complex and divisive topics of the day involve science. While deep ideological chasms cloud some discussions, the reality is that large segments of the American public are simply not trained as a scientists. For this reason they may tune out when scientists try to explain difficult topics, incorrectly oversimplify them to their own understanding, default to confirmation bias, or just believe what their favorite personality believes. However this should not discourage scientists from engaging with the public. I have discussed weather and climate issues from the White House to the Waffle House. Guess what? The message delivery should vary depending on audience. Based on my nearly 25 years of experience at NASA, the University of Georgia and The Weather Channel I offer nine tips for communicating science to non-scientists.

    1
    U.S. Secretary of State John Kerry, right, listens to scientist John Snow about the increased movement of icebergs across Antarctica at the Crary Science and Engineering Center, McMurdo Station in Antarctica Saturday, Nov. 12, 2016. (Mark Ralston/Pool Photo via AP)

    1. Know your audience. Many scientists are guilty of delivering the same message to the Rotary Club or Congressional Staffers that they give at a science conference. Research and understand your audience. Anthony Leiserowitz, an excellent climate communication scholar at Yale, once told me, “Not knowing your audience is like throwing darts at a dartboard with the lights off.”

    2. Don’t use jargon. Scientists throw terms like “bias,” “positive trend,” and”pdf” around easily. While most scientists associate “probability density function” with “pdf,” I bet the first thing that many in the public think about is a file format or attachment. Richard Sommerville and Susan Hassol provide a nice table of other jargony science terms to be cautious of in a Physics Today article.

    3. Get to the point. As scientists we are trained to describe a ton of details and background information before we give the final results. This is the very nature of how graduate students are trained to write their theses and dissertations. It is how scientists deliver presentations at conferences. For the public or policymakers this approach basically needs to be flipped. The key points or findings need to be delivered very early (see below) and it needs to be concise (think elevator speech).

    2
    Styles of communication. Source: AAAS

    4. Use analogies and metaphors. I find that analogies to real life work well. Though not perfect, when I use “weather is your mood, climate is your personality” or “if you don’t like the weather wait a few hours, if you don’t like the climate move” they resonate with people as a way to distinguish weather from climate. It also helps them to understand how silly it sounds when someone makes a statement about climate change based on today’s weather.

    5. Three points. Studies continue to show that three key points are effective with audiences. I often notice this seems to be difficult for scientists (remember I am a scientist) because they tend to want to tell the entire story and with every detail. Scientists need to work hard to keep their message memorable, meaningful and miniature. These are the so-called “Three M’s of Messaging” that the American Association for the Advancement of Science (AAAS) has also recommended in its Science Communications workshops.

    6. You are the expert. Often scientists must speak with the media and for many this uncomfortable. The key points to remember: (a) Be confident because you are the expert, (b) Don’t speculate or stretch if you don’t know (say so), and (c) Reflect on what you want (or do not want) on the record days, months or years later and use that as a filter.

    7. Use social media. Social media can be tricky but is a “net” good for science communication as long as you are able to deal with the very high noise to signal ratio, dissenting thoughts (whether expert or not), limits on messaging and time management. I cringe when I hear a scientist or scholar say they shy away from social media. Newsflash: It is not new. It is not just for the kids. It is an important medium that policymakers, media and other scholars follow.

    8. The myth of “popularizers.” Some within the academy can be a bit uppity and elitist at times. They turn their nose up at scholars that choose to take their message beyond journals, conferences and classrooms. More than ever I find that thinking to be a kind of “head in the sand” model. More than ever the expertise of scholars is needed in broader venues otherwise “non-experts” or “agendas” will gladly fill the void. In today’s world it is possible to achieve “scholarly” metrics while having a broader impact.

    9. Relate. As much as we understand the current and future challenges associated with our changing climate it is a struggle for many in the public to see beyond kitchen table issues affecting their families. The reality is that they are there but it is not always obvious. The science communicator must keep this in mind and find ways to relate the message to the core values of the person or audience. For some that may be economics, faith, defense or curiosity.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
  • richardmitnick 2:16 pm on November 25, 2016 Permalink | Reply
    Tags: , , , , Forbes   

    From Forbes: “The Hunt For Extrasolar Moons Heats Up” 

    ForbesMag

    Forbes Magazine

    Nov 21, 2016
    Bruce Dorminey

    Super-earths have been the exoplanet-hunting flavor of the last decade, but the moons of extrasolar planets could still be a good bet for finding extant life around some far-flung star. Problem is, to date, such moons have been observationally out of reach.

    1
    A hypothetical rendition of the Blue Moon created by “Frizaven” on the 3D Space Simulator Celestia, via Wikipedia.

    Yet if the European Space Agency (ESA) launches its ARIEL (Atmospheric Remote-sensIng Exoplanet Large-survey) mission by 2025, there remains a small chance that the spacecraft might actually spot a moon around a relatively hot, giant extrasolar planet. That is, one circling one of the roughly 500 stars the mission would survey. Or so says David Waltham, a University of London geophysicist.

    Despite years of sifting through data for their signature, to date, no exomoons have been confirmed. That’s arguably more of a testament to the rudimentary nature of our planet-hunting technology than a dearth of earth-sized moons around giant planets circling other sun-like stars.

    “At the moment, we simply don’t know whether earth-sized moons exist,” Waltham, author of Lucky Planet: Why Earth is Exceptional and What that Means for Life in the Universe, told me.

    The current search for exomoons, uses data from planets transiting across the face of their parent stars, the so-called transit method; as well as data from surveys to look for the telltale stellar wobble caused by an exoplanet in orbit around its host star.

    Planet transit. NASA/Ames
    Planet transit. NASA/Ames

    Such surveys sometimes even look for the wobble of an exoplanet caused by an orbiting exomoon.

    ARIEL will look for “transit time variations” (TTVs) in the exoplanets it finds, says Waltham. That is, small variations of less than a minute in the exact timing of a planet as it transits across the face of its parent star. Such transit variations could, in theory, be caused by the gravitational effect of a moon on its host planet; causing the planet to wobble around the planet-moon center of gravity.

    “Attempts to spot moon-generated TTVs in Kepler data have so far failed because the data is too noisy to allow such small effects to be seen,” said Waltham. “My hope had been that since ARIEL data will be from bright stars, the data would be less noisy and allow moons to be found.”

    But Waltham plans on looking for ARIEL’s transit time variations anyway.

    “Exomoons are unlikely around the majority of target planets for ARIEL but, if a few of the targeted planets orbit sun-sized stars, I might get lucky,” said Waltham.

    On another front, using data from NASA’s Kepler Space Telescope, the ongoing “Hunt for Exomoons with Kepler” (HEK) Project, led by Columbia University astronomer David Kipping, is continuing. Kipping and colleagues note that our own moon — only about 1% of earth’s mass — would be very hard to detect from light years away. But their search is still sensitive to statistically detecting an Earth-Moon combination for about one in every eight extrasolar planets they study.

    As for an earth-sized moon around a large planet?

    The project notes that statistically they would be sensitive to detecting one such exomoon for every three extrasolar planets surveyed.

    Our own anomalously large moon is about as inhospitable as they come. Most habitable planetary bodies require some sort of active geophysical tectonics or atmospheric recycling, which are usually not a feature of smaller bodies. And the only known moon with a substantial atmosphere, remains the Saturn’s moon of Titan, some 0.4 earth radii in size.

    Thus, what’s the next ground- or space-based effort to detect exomoons?

    Waltham says exomoon detection using transit timing variations will be very hard from the ground but it may be possible to see their direct transit signature using the next generation of very-large telescopes. But he says that NASA’s planned James Webb Space Telescope (JWST) due for launch in 2018, has the best chance of finding the first exomoons.

    NASA/ESA/CSA Webb Telescope annotated
    NASA/ESA/CSA Webb Telescope annotated

    As for the percentage of known exoplanetary systems that might also harbor habitable exomoons?

    “The statistics suggest that if earth-sized exomoons were really common, we’d probably have spotted one by now ,” Duncan Forgan, an astronomer at the U.K.’s University of St. Andrews, told me.

    Getting anything like a spectrum — which might tell us about the moon’s atmosphere or surface composition — will require much bigger telescopes than anything currently planned, Waltham says.

    However, Forgan says the biggest issue with exomoon bio-signatures is that if astronomers do get an exomoon spectrum, for the foreseeable future, they’ll probably be looking at it combined with its host planet’s spectrum as well.

    “There’s actually a worrying feature of this blending, which might convince us of habitability when the opposite is true,” said Forgan.

    Waltham says the best chance of detecting an exomoon is to look at a long-period, medium-sized planet orbiting a bright star. However, he cautions, astronomers would need to look for many decades to see enough transits to detect such long-period planets.

    Meanwhile, Kipping told me that there may still be some exomoon candidates in Kepler data of hundreds of extrasolar planets that he and colleagues are currently analyzing. But he says he is holding off on revealing more until their work is further along.

    See the full article here .

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  • richardmitnick 7:49 am on July 15, 2016 Permalink | Reply
    Tags: 2016 Ericcson Mobility Report, , Forbes, Internet Of Things On Pace To Replace Mobile Phones As Most Connected Device In 2018   

    From Forbes: “Internet Of Things On Pace To Replace Mobile Phones As Most Connected Device In 2018” 

    ForbesMag

    Forbes Magazine

    Jul 9, 2016
    Louis Columbus

    -Internet of Things (IoT) sensors and devices are expected to exceed mobile phones as the largest category of connected devices in 2018, growing at a 23% compound annual growth rate (CAGR) from 2015 to 2021.
    -By 2021 there will be 9B mobile subscriptions, 7.7B mobile broadband subscriptions, and 6.3B smartphone subscriptions.
    -Worldwide smartphone subscriptions will grow at a 10.6% CAGR from 2015 to 2012 with Asia/Pacific (APAC) gaining 1.7B new subscribers alone.

    These and other insights are from the 2016 Ericcson Mobility Report . Ericcson has provided a summary of the findings and a series of interactive graphics here. Ericcson created the subscription and traffic forecast baseline this analysis is based on using historical data from a variety of internal and external sources. Ericcson also validated trending analysis through the use of their planning models. Future development is estimated based on macroeconomic trends, user trends (researched by Ericsson ConsumerLab), market maturity, technology development expectations and documents such as industry analyst reports, on a national or regional level, together with internal assumptions and analysis.In addition, Ericsson regularly performs traffic measurements in over 100 live networks in all major regions of the world. For additional details on the methodology, please see page 30 of the study.

    Key takeaways from the 2016 Ericcson Mobility Report include the following:

    Internet of Things (IoT) sensors and devices are expected to exceed mobile phones as the largest category of connected devices in 2018, growing at a 23% compound annual growth rate (CAGR) from 2015 to 2021. Ericcson predicts there will be a total of approximately 28B connected devices worldwide by 2021, with nearly 16B related to IoT. The following graphic compares cellular IoT, non-cellular IoT, PC/laptop/tablet, mobile phones, and fixed phones connected devices growth from 2015 to 2021.

    2

    400 million IoT devices with cellular subscriptions were active at the end of 2015, and Cellular IoT is expected to have the highest growth among the different categories of connected devices, reaching 1.5B connections in 2021. Ericcson cites the growth factors of 3GPP standardization of cellular IoT technologies and cellular connections benefitting from enhancements in provisioning, device management, service enablement and security. The forecast for IoT connected devices: cellular and non-cellular (billions) is shown.

    3

    Global mobile broadband subscriptions will reach 7.7B by 2021, accounting for 85% of all subscriptions. Ericcson is predicting there will be 9B mobile subscriptions, 7.7B mobile broadband subscriptions, and 6.3B smartphone subscriptions by 2021 as well. The following graphic compares mobile subscriptions, mobile broadband, mobile subscribers, fixed broadband subscriptions, and mobile CPs, tablets and mobile routers’ subscription growth.

    4

    Worldwide smartphone subscriptions will grow at a 10.6% compound annual growth rate (CAGR) from 2015 to 2012. Ericcson predicts that the Asia/Pacific (APAC) region will gain 1.7B new subscribers. The Middle East and Africa will have smartphone subscription rates will increase more than 200% between 2015–2021. The following graphic compares growth by global region.

    5

    Mobile subscriptions are growing around 3% year-over-year globally and reached 7.4B in Q1 2016. India is the fastest growing market regarding net additions during the quarter (+21 million), followed by Myanmar (+5 million), Indonesia, (+5 million), the US (+3 million) and Pakistan (+3 million). The following graphic compares mobile subscription growth by global region for Q1, 2016.

    6

    90% of subscriptions in Western Europe and 95% in North America will be for LTE/5G by 2021. The Middle East and Africa will see a dramatic shift from 2G to a market where almost 80% of subscriptions will be for 3G/4G. The following graphic compares mobile subscriptions by region and technology.

    7

    Mobile video traffic is forecast to grow by around 55% annually through 2021, accounting for nearly 67% of all mobile data traffic. Social networking traffic is predicted to attain a 41% CAGR from 2015 to 2021. The following graphic compared the growth of mobile traffic by application category and projected mobile traffic by application category per month.

    8

    Ericcson also provided mobile subscription, traffic per device, mobile traffic growth forecast, and monthly data traffic per smartphone. The summary table is shown below:

    9

    See the full article here .

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  • richardmitnick 10:28 am on August 31, 2015 Permalink | Reply
    Tags: , Forbes,   

    From Forbes: “What Has Quantum Mechanics Ever Done For Us?” 

    ForbesMag

    Forbes Magazine

    Aug 13, 2015
    Chad Orzel

    1
    Intel Corp. CEO Paul Otellini show off chips on a wafer built on so-called 22-nanometer technology at the Intel Developers’ Forum in San Francisco, Tuesday, Sept. 22, 2009. Those chips are still being developed in Intel’s factories and won’t go into production until 2011. Each chip on the silicon “wafer” Otellini showed off has 2.9 billion transistors. (AP Photo/Paul Sakuma)

    In a different corner of the social media universe, someone left comments on a link to Tuesday’s post about quantum randomness declaring that they weren’t aware of any practical applications of quantum physics. There’s a kind of Life of Brian absurdity to posting this on the Internet, which is a giant world-spanning, life-changing practical application of quantum mechanics. But just to make things a little clearer, here’s a quick look at some of the myriad everyday things that depend on quantum physics for their operation.

    Computers and Smartphones

    At bottom, the entire computer industry is built on quantum mechanics. Modern semiconductor-based electronics rely on the band structure of solid objects. This is fundamentally a quantum phenomenon, depending on the wave nature of electrons, and because we understand that wave nature, we can manipulate the electrical properties of silicon. Mixing in just a tiny fraction of the right other elements changes the band structure and thus the conductivity; we know exactly what to add and how much to use thanks to our detailed understanding of the quantum nature of matter.

    Stacking up layers of silicon doped with different elements allows us to make transistors on the nanometer scale. Millions of these packed together in a single block of material make the computer chips that power all the technological gadgets that are so central to modern life. Desktops, laptops, tablets, smartphones, even small household appliances and kids’ toys are driven by computer chips that simply would not be possible to make without our modern understanding of quantum physics.

    2
    Green LED lights and rows of fibre optic cables are seen feeding into a computer server inside a comms room at an office in London, U.K., on Tuesday, Dec. 23, 2014. Vodafone Group Plc will ask telecommunications regulator Ofcom to guarantee that U.K. wireless carriers, which rely on BT’s fiber network to transmit voice and data traffic across the country, are treated fairly when BT sets prices and connects their broadcasting towers. Photographer: Simon Dawson/Bloomberg

    Unless my grumpy correspondent was posting from the exact server hosting the comment files (which would be really creepy), odds are very good that comment took a path to me that also relies on quantum physics, specifically fiber optic telecommunications. The fibers themselves are pretty classical, but the light sources used to send messages down the fiber optic cables are lasers, which are quantum devices.

    The key physics of the laser is contained in a 1917 paper [Albert] Einstein wrote on the statistics of photons (though the term “photon” was coined later) and their interaction with atoms. This introduces the idea of stimulated emission, where an atom in a high-energy state encountering a photon of the right wavelength is induced to emit a second photon identical to the first. This process is responsible for two of the letters in the word “laser,” originally an acronym for “Light Amplification by Stimulated Emission of Radiation.”

    Any time you use a laser, whether indirectly by making a phone call, directly by scanning a UPC label on your groceries, or frivolously to torment a cat, you’re making practical use of quantum physics.

    Atomic Clocks and GPS

    One of the most common uses of Internet-connected smart phones is to find directions to unfamiliar places, another application that is critically dependent on quantum physics. Smartphone navigation is enabled by the Global Positioning System, a network of satellites each broadcasting the time. The GPS receiver in your phone picks up the signal from multiple clocks, and uses the different arrival times from different satellites to determine your distance from each of those satellites. The computer inside the receiver then does a bit of math to figure out the single point on the surface of the Earth that is that distance from those satellites, and locates you to within a few meters.

    This trilateration relies on the constant speed of light to convert time to distance. Light moves at about a foot per nanosecond, so the timing accuracy of the satellite signals needs to be really good, so each satellite in the GPS constellation contains an ensemble of atomic clocks. These rely on quantum mechanics– the “ticking” of the clock is the oscillation of microwaves driving a transition between two particular quantum states in a cesium atom (or rubidium, in some of the clocks).

    Any time you use your phone to get you from point A to point B, the trip is made possible by quantum physics.

    Magnetic Resonance Imaging

    3
    Leila Wehbe, a Ph.D. student at Carnegie Mellon University in Pittsburgh, talks about an experiment that used brain scans made in this brain-scanning MRI machine on campus, Wednesday, Nov. 26, 2014. Volunteers where scanned as each word of a chapter of “Harry Potter and the Sorcerer’s Stone” was flashed for half a second onto a screen inside the machine. Images showing combinations of data and graphics were collected. (AP Photo/Keith Srakocic)

    The transition used for atomic clocks is a “hyperfine” transition, which comes from a small energy shift depending on how the spin of an electron is oriented relative to the spin of the nucleus of the atom. Those spins are an intrinsically quantum phenomenon (actually, it comes in only when you include special relativity with quantum mechanics), causing the electrons, protons, and neutrons making up ordinary matter behave like tiny magnets.

    This spin is responsible for the fourth and final practical application of quantum physics that I’ll talk about today, namely Magnetic Resonance Imaging (MRI). The central process in an MRI machine is called Nuclear Magnetic Resonance (but “nuclear” is a scary word, so it’s avoided for a consumer medical process), and works by flipping the spins in the nuclei of hydrogen atoms. A clever arrangement of magnetic fields lets doctors measure the concentration of hydrogen appearing in different parts of the body, which in turn distinguishes between a lot of softer tissues that don’t show up well in traditional x-rays.

    So any time you, a loved one, or your favorite professional athlete undergoes an MRI scan, you have quantum physics to thank for their diagnosis and hopefully successful recovery.

    So, while it may sometimes seem like quantum physics is arcane and remote from everyday experience (a self-inflicted problem for physicists, to some degree, as we often over-emphasize the weirder aspects when talking about quantum mechanics), in fact it is absolutely essential to modern life. Semiconductor electronics, lasers, atomic clocks, and magnetic resonance scanners all fundamentally depend on our understanding of the quantum nature of light and matter.

    But, you know, other than computers, smartphones, the Internet, GPS, and MRI, what has quantum physics ever done for us?

    See the full article here.

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  • richardmitnick 2:05 pm on December 31, 2014 Permalink | Reply
    Tags: , Forbes   

    From Forbes: :Solar System Set For Eventual Collision With Stellar Orange Dwarf” 

    ForbesMag

    Forbes Magazine

    12/29/2014
    Bruce Dorminey

    A local orange dwarf star has a 90 percent probability of passing within the orbit of our outer solar system’s Oort Cloud between 240,000 and 470,000 years from now, says the author of a new study detailing the computer-modeled orbits of more than 50,000 nearby stars.

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    Oort Cloud

    In a paper just accepted for publication in the journal Astronomy & Astrophysics, Coryn Bailer-Jones, an astrophysicist at Germany’s Max Planck Institute for Astronomy in Heidelberg, and the paper’s sole author, found that of 14 stars coming within 3 light years of Earth, the closest encounter is likely to be HIP 85605, which now lies some 16 light years away in the constellation of Hercules.

    Like agitated bees circling a hive, we live in a dynamic sea of low-mass stars. More than a few buzz our own star on timescales of thousands to millions of years. But how many of these stellar interlopers perturb a fraction of the estimated few trillion comets that make up the Oort Cloud? That is, the grand reservoir of comets which circles our own solar system at a distance of nearly a light year. That’s the crux of this new paper which, among other things, posits that these passing stars cause a significant number of the Oort Cloud’s kilometer-sized cometary bodies to be injected into Earth-crossing orbits.

    “This study is limited to stars for which we have accurate distances and velocities; which, in turn, limits us to stars currently within a few tens of [light years] from the Sun,” Bailer-Jones told Forbes. He calculates that some 40 stars ‘have come’ or ‘will come’ within an estimated 6.4 light years of our Sun over a time-frame spanning 20 million years in Earth’s past to 20 million years in our future.

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    An artist’s concept of a comet storm around Eta Corvi. Credit: NASA/JPL-Caltech

    Using [Sir Isaac] Newton’s laws and standard numerical computations, Bailer-Jones traced each star’s trajectory backwards and forwards in time through “a sequence of a large number of very short line segments.” He says he also did the same for the Sun, since it, too, is moving around our galactic disk. Allowing for observational errors, he slightly changed each star’s initial coordinates some 10,000 times in order to build up what he terms a “probability distribution” of how close the stars actually came or will come to the Sun.

    Such stellar interlopers can threaten life on Earth in three basic ways. Their gravity can cause the injection of Oort Cloud comets into our inner solar system. Passing massive hot stars could destroy Earth’s atmosphere via powerful ultraviolet (UV) radiation. And a very small fraction of passing stars might even go supernova over the estimated 30,000 year time-frame that they spend crossing through the Oort Cloud. Bailer-Jones says supernova remnants could induce long-term global cooling through the follow-on production of Nitrous Oxide (NO2) in our atmosphere.

    Is there any evidence for this in Earth’s climate history?

    “We see radioactive isotopes on Earth which point to nearby supernovae over the past few million years,” said Bailer-Jones. “These isotopes would either have been deposited directly by supernova debris, or were produced by high-energy particles coming from the supernova.”

    As for incoming comets?

    The largest known such perturbation may have been caused by gamma Microscopii, a solar type star some two and half times as large as the Sun, which less than four million years ago came within a light year.

    Is there a causal link with Earth’s geological impact record?

    “There are impact craters of similar age, but this does not indicate a causal connection,” said Bailer-Jones, who concludes it would be very difficult to make a direct link between an uptick in earth impacts and a individual passing star.

    In fact, obtaining these answers remains very much a work in progress. Bailer-Jones hopes that forthcoming data from the European Space Agency’s Gaia space observatory will allow astronomers to statistically investigate the link between such stellar close encounters and the Earth impact record.

    ESA Gaia satellite
    ESA Gaia Camera
    ESA/Gaia with camera

    But such encounters do happen over all timescales. Bailer-Jones notes that Van Maanen’s star, the closest known solitary white dwarf — a burned out stellar remnant — lies some 12 light years away in Pisces. It encountered our own Sun only 15,000 years ago.

    However, as Bailer-Jones notes, if the astrometry detailing HIP 85605’s current position and velocity on the sky turn out to be incorrect, then Gliese 710 would be the Oort Cloud’s next stellar perturber.

    Bailer-Jones says his own study gives a 90 percent probability that Gliese 710, a small sunlike star some 64 light years away in the constellation of Serpens, will make its closest approach of a little more than a light year some 1.30 to 1.5 million years from now.

    By some estimates, Gliese 710’s passing will cause as many as 2.4 million comets to move into Earth-crossing orbits. As noted in my book “Distant Wanderers,” these comets will only gradually arrive in our vicinity over a period of some two million years. Some will be swept up by Jupiter’s gravity; others will repeatedly circle the Sun. A few will be flung out of the solar system altogether.

    But what this new cometary influx will actually mean for life here in the inner solar system is still up for grabs.

    See the full article here.

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  • richardmitnick 8:49 am on July 15, 2014 Permalink | Reply
    Tags: , , , , , Forbes,   

    From Forbes: “New Venus NASA Missions Could Lift Planet’s Hellish Veil” 

    forbes

    7/15/2014
    Bruce Dorminey

    If Mars is mysterious, Venus is truly scary. Long called Earth’s twin, it’s only four months away via unmanned probe and lies more than 70 percent of Earth’s distance from the Sun.

    But with surface pressures and temperatures high enough to melt lead and crush steel, why is Venus so hauntingly different from Earth? And when did it go bad?

    “Venus and Earth are virtually identical twins; they’re almost the same size,” said Robert Herrick, a planetary geophysicist at the University of Alaska in Fairbanks. “But Venus is completely uninhabitable; we really don’t understand how that dichotomy came about.”

    The European Space Agency’s (ESA) Venus Express orbiter has spent the last eight years trying to dissect its hellish atmosphere and surface. But now with dwindling fuel, by year’s end the spacecraft is expected to make its final plunge into Venus’ toxic atmosphere.
    Scale representations of Venus and the Earth s…

    ESA Venus Express
    ESA/Venus Express

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    Scale representations of Venus and the Earth shown next to each other. Venus is only slightly smaller. (Photo credit: Wikipedia)

    While Venus Express has made scientific progress, planetary scientists say, a few major puzzles have yet to be solved.

    Larry Esposito, a planetary scientist at the University of Colorado at Boulder, says the most puzzling things are: How did Venus go bad? How did the high-wind dynamics of the atmosphere arise on Venus? What is its surface made of? And does Venus still have volcanic activity?

    Venus Express took infrared images of the planet’s surface and found that its biggest volcanoes do indeed indicate lava flow there within the last 250,000 years.

    “Venus Express also detected a sudden increase in sulfur dioxide; the same thing that comes out of unscrubbed coal-powered plants on earth,” said Esposito. “But on Venus Express, it was interpreted as a possible real-time volcanic eruption.”

    One explanation is that Venus undergoes giant volcanic eruptions every few decades. But how do these putative eruptions contribute to Venus’ ongoing dense, noxious atmosphere?

    Calculations of surface-atmosphere interactions indicate that the planet’s atmospheric sulfur should be “sopped up” by the surface in a few tens of millions of years, says Kevin Baines, a planetary scientist at NASA JPL and the University of Wisconsin at Madison. Baines says this means if the present cloudy atmosphere is typical and ongoing, then there must be active volcanism to resupply the atmosphere with sulfur. He notes that “a hot atmosphere” may “soften” the surface, allowing increased sulfur emission.

    One of a handful of potential Venus mission proposals — each vying for a slot in NASA’s Discovery-class mission program — could help clear up Venus’ remaining mysteries.

    A proposed VASE (Venus Atmosphere and Surface Explorer) mission might skim the clouds and on a final landing even get data from the surface, says Mark Bullock, a planetary scientist at the Southwest Research Institute in Boulder, and a VASE definition team member.

    But Bullock says “if you really want to understand this you have to put lots of balloons in the atmosphere to understand how the surface and the atmosphere interact.”

    As for why Venus ultimately became so inhospitable?

    The short answer is that as the Sun increases in luminosity, the inner edge of our solar system’s habitable zone also continually moves outward; thus, long ago, Venus simply became too hot to hold onto its liquid water.

    This loss, says Baines, was likely caused by the “ravaging solar wind” and the effects of ultraviolet photons “ripping water molecules into hydrogen and oxygen,” which in turn led to the escape of Venus’ hydrogen into space.

    “To me, the main puzzle is when did Venus lose its oceans,” said Bullock. “The paradigm is that Venus lost its oceans up to 600 million years after its formation. But there is absolutely no data which contradicts the possibility that Venus was actually Earth-like for billions of years.”

    Could Earth suffer a similar fate?

    “Earth is definitely on a path to a Venus-like condition and anthropogenic carbon emissions are the beginning of it,” said Bullock. “That’s dramatic, but there’s no question that Earth will go in that direction.”

    As for finding proof of Venus’ ancient lakes or seas, Baines says a surface lander that sampled rocks and found water-bearing materials or materials that could only be formed in standing water would clinch that.

    However, Bullock says there are also people who think it may not ever have had an ocean and its water was always steam.

    In terms of our geological understanding of Venus, Herrick says we’re where we were with Mars three decades ago. NASA’s 1990s Magellan mission to Venus was only able to see things several football fields across and larger. But he says a newer generation of Synthetic Aperture Radars (SAR)s is capable of giving researchers much better images.

    For a planet with a dense atmosphere, like Venus, Herrick says synthetic aperture radar would image the surface and researchers would interpret the black and white image results very much like images from planets with more transparent atmospheres.

    A proposed RAVEN (Radar at Venus) mission would compare a new radar-imaging orbiter focused on understanding Venus’ geology as well as identifying future potential landing sites. One of its goals would be to definitively determine whether Venus has continents and whether such putative continents are composed of granitic rock, as here on Earth.

    “We don’t know that the high-lying regions on Venus are actually like Earth’s continents,” said Esposito. “We haven’t identified granite yet on Venus and don’t know its major surface rock types.”

    Venus doesn’t have Earth-styled plate tectonics, says Herrick, but he says we don’t have enough high-resolution topography information to understand how Venus is releasing its heat.

    NASA will put out a Discovery mission Announcement of Opportunity this September. By year’s end, the agency is expected to then pick three to five proposals for further study. Conceivably, one or more of a handful of competing Venus mission proposals may ultimately chosen and see launch as early as 2020.

    As for longer range Venus missions?

    “New missions that orbit the planet for decades,” said Baines, “may allow us to complete the picture of what happened to Venus to convert it from a verdant oasis to a (non)living hell.”

     
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