Tagged: BBC Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 12:46 pm on March 8, 2015 Permalink | Reply
    Tags: , , BBC,   

    From BBC: “LHC restart: ‘We want to break physics'” 


    4 March 2015
    Jonathan Webb

    Inside the CMS experiment, the beam pipe is dwarfed by huge cylindrical detectors that will try to capture everything that emerges from the collisions.

    As the Large Hadron Collider (LHC) gears up for its revamped second run, hurling particles together with more energy than ever before, physicists there are impatient. They want this next round of collisions to shake their discipline to its core.

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

    “I can’t wait for the switch-on. We’ve been waiting since January 2013 to have our proton beams back,” says Tara Shears, a particle physics professor from the University of Liverpool.

    Prof Shears is raising her voice over the occasional noise of fork-lift trucks and tools, as well as the constant hum of the huge experimental apparatus behind her: LHCb, one of four collision points spaced around the LHC’s 27km circumference.

    CERN LHCb New II

    All this noise reverberates because we are perched at the side of an imposing cavern, 30 storeys beneath the French-Swiss border.

    The other three experiments – Atlas, CMS and Alice – occupy similar halls, buried elsewhere on this famous circular pipeline.



    ‘Everything unravels’

    In mid-March two beams of protons, driven and steered by super-cooled electromagnets, will do full circuits of the LHC in both directions – for the first time in two years. When that happens, there will be nobody between here and ground level. Then in May, if the protons’ practice laps proceed without a hitch, each of the four separate experiments will recommence its work: funnelling those tightly focussed, parallel beams into a head-on collision and measuring the results. For us, now, the other stations on the ring are a 10-20 minute drive away; for the protons, a lap will take less than one ten-thousandth of a second. They have the advantage of travelling a whisker under the speed of light.

    They are moving with so much energy that when they collide, things get hot. Historically hot. “We’re recreating temperatures that were last seen billionths of a second after the Big Bang,” Prof Shears explains. “When you get to this hot temperature, matter dissociates into atoms, and atoms into nuclei and electrons. “Everything unravels to its constituents. And those constituents are what we study in particle physics.”

    The two beams of protons are focussed into a tiny, intense blast before being put on a collision course

    Alongside more pedestrian items, like electrons, or the quarks that combine to make protons and neutrons, these constituents include the world-famous Higgs boson.

    Higgs Boson Event
    Higgs Event

    This longed-for and lauded particle – the last major ingredient in the Standard Model of particle physics – was detected by the teams at Atlas and CMS in 2012.


    Then in early 2013, after countless further collisions with valuable but less sensational results, the LHC was wound down for a planned hiatus.


    What is an electronvolt?


    Particle accelerators use strong electric fields to speed up tiny pieces of matter
    An electronvolt (eV) is the energy gained by one electron as it accelerates through a potential of one volt
    The LHC reaches particle energies measured in trillions of eV: teraelectronvolts (TeV)
    This is only the energy in the motion of a flying mosquito – per particle
    The LHC beams contain hundreds of trillions of particles, each travelling at 99.99999999% of the speed of light
    In total, an LHC beam has the energy of a TGV high-speed train travelling at 150 km/h


    Renewed vigour

    The two intervening years have been spent servicing and improving the collider.

    “All the magnets have been surveyed, the connections between them have been X-rayed and strengthened, and all the electrical and cryogenic systems have been checked out and optimised,” Prof Shears says. This effort – between one and two million hours of work, all told – means that the LHC is now ready to operate at its “design energy”. Its initial run, after a dramatic false start in 2008, only reached a maximum collision energy of eight trillion electronvolts. That came after a boost in 2012 and the extra power delivered the critical Higgs observations within a few months.

    When they kick off in May, the proton collisions will be at 13 trillion electronvolts: a leap equivalent to that made by the LHC when it first went into operation and dwarfed the previous peak, claimed by the 6km Tevatron accelerator in the US. “It’s a really significant step in terms of what we might be able to see in the Universe,” says Prof Shears.

    “The design energy is a little higher again, at 14 TeV. We want to make sure that we can run close to it, first of all. If operations there are smooth, then subsequently, after next year, we can put the energy up that last little bit.” Alongside this radical hike in the beams’ energy, the experiments housed at the four collision sites have also had time to upgrade. Some have added extra detectors as well as finishing, mending or improving equipment that was built for the first run.

    Build it up, tear it down

    In a sense, one of the shiniest new items in the LHC’s armoury for Run Two is the Higgs boson. Now that its existence is confirmed and quantified, it can inform the next round of detection and analysis. “It’s a new door – a new tool that we can use to probe what is beyond the Standard Model,” says Dr Andre David, one of the research team working on the CMS experiment. Dr David is driving me from the CMS site, in France, back down the valley between the Jura Mountains and Lake Geneva to the main Cern headquarters. This main site, adjacent to the Atlas experiment, sits on the southern side of the LHC’s great circle and straddles the Swiss border.

    Data flow: The LHC has immeasurable miles of cables to carry experimental data – as well as better mobile phone signal than you can get at ground level

    He emphasises that the Higgs is much more than the final item on the Standard Model checklist; there is a great deal still to find out about it. “It’s like a new wrench that we still have to work out exactly where to fit.” Prof Shears agrees: “We’ve only had about a thousand or two of these new particles, to try and understand their nature.

    “And although it looks like the Higgs boson that we expect from our theory, there’s still a chance that it might have partners that would then tell us that we’re not looking at our normal theory at all. We’re looking at something deeper and more exotic.”

    That is the central impatience that is itching all the physicists here: they want to find something that falls completely outside what they expect or understand. “The data so far has confirmed that our theory is really really good, which is frustrating because we know it’s not!” Prof Shears says. “We know it can’t explain a lot of the Universe.

    “So instead of trying to test the truth of this theory, what we really want to do now is break it – to show where it stops reflecting reality. That’s the only way we’re going to make progress.”

    In the canteen at Cern headquarters I meet Dr Steven Goldfarb, a physicist and software developer on the Atlas team. His sentiments are similar. “We have a fantastic model – that we hate,” he chuckles. “It has stood up to precision measurements for 50 years. We get more and more precise, and it stands up and stands up. But we hate it, because it doesn’t explain the universe.”


    Dark matter: present but invisible

    In fact, only about 5% of the universe is accounted for by the Standard Model. Physicists think that the rest is made up of dark energy (70%) and dark matter (25%) – but these are still just proposals without any experimental evidence. Based on how fast galaxies move and spin, we know there is much more stuff in the universe than what we can see with telescopes. One idea for a “new physics” that might allow for more particles, including the mysterious constituents of dark matter, is supersymmetry.

    Supersymmetry standard model
    Standard Model of Supersymmetry

    It has also never been glimpsed in data from the LHC or elsewhere, but remains a popular concept with theorists. Supersymmetry suggests that all the particles we know about have heavier, “super” partners – as yet unseen by science.

    That failure doesn’t faze the theory’s fans, Dr Golfarb explains. “If you say to someone who really likes supersymmetry, ‘Hey, why haven’t we found any of the particles yet?’ they’ll say, ‘We’ve found half of the particles! We just need to find the other half…'”

    The Standard Model equation is etched in stone outside Cern’s control room – but physicists inside want to find something it can’t explain

    Some of those missing, hypothetical particles – notably the gluino and the neutralino – have been mooted as the most likely first results from LHC Run Two.

    They also make promising candidate building blocks for dark matter. But the researchers are open to other possibilities. Dr Goldfarb says the search need not focus on specific, ghostly particles: “It doesn’t have to be supersymmetry. You can also just look for dark matter. That’s why we build our detectors perfectly hermetically.”

    CMS and Atlas are the two “general-purpose” experiments at the LHC. Both of them have detectors completely surrounding the collision point, so that nothing can escape.

    Well, almost nothing. “You can’t build a neutrino detector – so neutrinos do get out. But we know under what circumstances and how often there ought to be neutrinos. So we can account for the missing energy.” What the team really wants to see is a chunk of missing energy that they categorically cannot account for. “When you see a lot of missing momentum – more than is predicted in standard model – then you may have found a candidate for dark matter,” Dr Goldfarb explains.


    Antimatter: missing altogether

    Even within the 5% of the universe that we do know about, there is a baffling imbalance. The Big Bang ought to have produced two flavours of particle – matter and antimatter – in equal amounts. When those two types of particle collide, they “annihilate” each other. A lot of that sort of annihilation went on, physicists say, and everything we can see in the universe is just the scraps left behind. But puzzlingly, nearly all of those scraps are of one flavour: matter.

    “You just don’t get antimatter in the universe,” says Prof Shears. “You get it in sci-fi and you get it when things decay radioactively, but there are no good deposits of it around.” This glaring absence is “one of the biggest mysteries we have”, she adds. And it is the primary target of the LHCb experiment.

    There, a series of slab-shaped detectors is waiting to try and pinpoint the difference between the particles and anti-particles that pop out of the proton collisions. Run One did reveal some of those differences – but nothing that could explain the drastic tipping of the universal scales towards matter.

    The beam pipe runs directly through the middle of the huge, slab-shaped detectors at LHCb

    “We think now that the answer has to lie in some new physics,” says Prof Shears. She hopes the near doubling of the collision energy will offer a peek. “We’ve got a million crazy ideas. All we can do is to keep our options open, to sift through the data – and to look for the unexpected.”

    Gravity gap

    There are other questions, too. Gravity, somewhat alarmingly, is nowhere to be found in the Standard Model. “There’s no gravity on that mug,” says Dr Goldfarb, pointing to an LHC souvenir with the model’s equation emblazoned on its side. “That’s annoying! But there’s no answer in sight.” And there is always the ongoing quest to smash the things we currently think are the smallest in existence, and find smaller ones. Dr Goldfarb calls this “the oldest physics” and imagines a cavewoman – the first physicist – banging rocks together to see what was inside.

    Final touches at CMS: ‘It’s like you’ve put a ship in the harbour and replaced every single plank’ “We’re still doing that today, and we still wonder what’s inside,” he says. “There’s nothing that discounts the idea that electrons, or quarks, are made up of something else. We just call them fundamental because as far as we know, they are.”

    The extra power in Run Two might produce just this kind of fundamental fruit. “The more energy we have for these collisions, the smaller the bits that we can look at,” says Dr David.

    “The ultimate goal here is to understand what matter is made of.” And the world’s largest laboratory is not just repaired, but renewed and ready for that goal. “It’s like you’ve put a ship in the harbour and replaced every single plank,” Dr David says with pride. “It’s not the same ship. It’s a whole new ship and it’s going on a new adventure.”

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

  • richardmitnick 12:10 pm on March 3, 2015 Permalink | Reply
    Tags: , BBC, ,   

    From BBC: “New Higgs detection ‘closes circle’” 


    3 March 2015
    Jonathan Webb

    The low energy work is separate from studies at the Large Hadron Collider

    Physicists who detected a version of the Higgs Boson in a superconductor say their discovery closes a “historical circuit”.

    They also stressed that the low-energy work was “completely separate” from the famous evidence gathered by the Large Hadron Collider.

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

    Superconductivity was the field of study where the idea for the Higgs originated in the 1960s. But the particle proved impossible to witness because it decays so fast. This new signature was glimpsed as very thin, chilled layers of metal compounds were pushed very close to the boundary of their superconducting state. This process creates a “mode” in the material that is analogous to the Higgs Boson but lasts much longer.

    Rather than the study of particles, it belongs in the field known condensed matter physics; it also uses much less energy than experiments at the LHC, where protons are smashed together at just under the speed of light. It was at the LHC in 2012 that the Higgs Boson, believed to give all the other subatomic particles their mass, was detected for the very first time.

    The new superconductor discovery was presented amid much discussion at this week’s March Meeting of the American Physical Society in San Antonio, Texas. It also appeared in the journal Nature Physics in January. Speaking at the meeting, Prof Aviad Frydman from Bar Ilan University in Israel responded in no uncertain terms to the suggestion that his work could substitute for the LHC. “That’s complete nonsense,” he told the BBC. “In fact it’s kind of embarrassing.”

    The team used superconducting films made from compounds of niobium (pictured here as a fibre) and indium

    Prof Frydman said the convergence of results from “two extremes of physics” was the most striking aspect of his findings, which were the fruit of a collaboration spanning Israel, Germany, Russia, India and the USA. “You take the high energy physics, which works in gigaelectronvolts. And then you take superconductivity, which is low energy, low temperature, one millivolt. “You have 10 to the 15 (one quadrillion) orders of magnitude between them, and the same physics governs both! That is the nice thing.”

    “It’s not that our experiment can replace the LHC. It’s completely separate.”

    Superconductors are materials that, when under critical conditions including temperatures near absolute zero (-273C), allow electrons to move with complete freedom. It was attempts to understand this property that ultimately led to Peter Higgs and others proposing the now-famous boson. “In the 1960s there were two distinct, basic problems. One was superconductivity and one was the mass of particles,” Prof Frydman explained.

    “People like Phil Anderson developed this mechanism for understanding superconductivity. And the guys from high energy saw this kind of solution, and applied it to high energy physics. That’s where the Higgs actually came from.” So the detection of a superconducting Higgs, he added, is “closing a historical circuit”. This closure was a long time coming. Detecting the Higgs in a superconductor had seemed almost impossible. This was because the energy required to excite (and detect) the Higgs mode – even though vastly less than that needed to generate its analogous particle inside the LHC – would destroy the very property of superconductivity. The Higgs mode would vanish almost before it arose. But when Prof Frydman and his colleagues held their thin films in conditions very close to the “critical transition” between being a superconductor and an insulator, they created a longer-lived, lower-energy Higgs mode.

    Other claims of a superconducting Higgs have been made in the past, including one in 2014. They have all faced criticism. Indeed, Prof Frydman’s conference presentation was also greeted with intense questions from others in the field. “Like any physical finding, there are different interpretations,” he said. “The Cern experiment is also being contested.”

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

  • richardmitnick 6:30 am on February 10, 2015 Permalink | Reply
    Tags: , BBC, ,   

    From BBC: “Mammals on brink of ‘extinction calamity'” in Australia 


    10 February 2015
    Helen Briggs

    The endangered northern quoll, a mammal species native to Australia

    Australia has lost one in ten of its native mammals over the last 200 years in what conservationists describe as an “extinction calamity”.

    No other nation has had such a high rate of loss of land mammals over this time period, according to scientists at Charles Darwin University, Australia.

    The decline is mainly due to predation by the feral cat and the red fox, which were introduced from Europe, they say.

    Large scale fires to manage land are also having an impact.

    As an affluent nation with a small population, Australia’s wildlife should be relatively secure from threats such as habitat loss.

    But a new survey of Australia’s native mammals, published in the journal Proceedings of the National Academy of Sciences, suggests the scale of the problem is more serious than anticipated.

    Since 1788, 11% of 273 native mammals living on land have died out, 21% are threatened and 15% are near threatened, the study found. Marine mammals are faring better.

    Shy species

    “No other country has had such a high rate and number of mammal extinctions over this period, and the number we report for Australia is substantially higher than previous estimates,” said conservation biologist John Woinarski, who led the research.

    “A further 56 Australian land mammals are now threatened, indicating that this extremely high rate of biodiversity loss is likely to continue unless substantial changes are made.

    “The extent of the problem has been largely unappreciated until recently because much of the loss involves small, nocturnal, shy species with [little] public profile – few Australians know of these species, let alone have seen them, so their loss has been largely unappreciated by the community.”

    The brush-tailed rabbit-rat, a mammal species native to Australia that is listed as a near-threatened species by the International Union for Conservation of Nature The brush-tailed rabbit-rat, a mammal species native to Australia that is listed as a near-threatened species by the International Union for Conservation of Nature

    In time, iconic species such as the koala will also decline, said the researchers, from Charles Darwin University, Southern Cross University and the Department of Parks and Wildlife in Wanneroo.

    The prospects for Australia’s wildlife can be improved but is “a very formidable challenge”, they added.

    It is estimated there are between 15 and 23 million wild cats living on the continent.

    Practical measures to protect native species include boosting biosecurity on islands off the mainland, which have fewer feral cats and foxes.

    The islands could also act as arks for endangered species, while more careful use of fire and control measures to wipe out foxes and feral cats are also being considered.

    But the researchers warn that Australians may ultimately need to consider the way they live on the land to stem the loss of natural assets.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

  • richardmitnick 7:16 pm on November 12, 2014 Permalink | Reply
    Tags: , BBC,   

    From BBC: “Are we sending aliens the right messages?” 



    12 November 2014
    Tracey Logan

    Despite decades of sending sounds and pictures into space no aliens have responded. Have we been doing it wrong? Tracey Logan investigates, and discovers some novel attempts to make contact – including the smells of our planet.


    For decades we’ve been sending signals – both deliberate and accidental – into space, and listening out for alien civilisations’ broadcasts. But what is the plan if one day we were to hear something?

    Artist Carrie Paterson has long dreamed of beaming messages far out to the emptiness of space. Except her messages would have an extra dimension – smell.

    By broadcasting formulae of aromatic chemicals, she says, aliens could reconstruct all sorts of whiffs that help to define life on Earth: animal blood and faeces, sweet floral and citrus scents or benzene to show our global dependence on the car. This way intelligent life forms on distant planets who may not see or hear as we do, says Paterson, could explore us through smell, one of the most primitive and ubiquitous senses of all.

    It is nearly 40 years since the Arecibo facility sent messages out into space

    Her idea is only the latest in a list of attempts to hail intelligent life outside of the Solar System. Forty years ago this month, the Arecibo radio telescope in Puerto Rico sent an iconic picture message into space – and we’ve arguably been broadcasting to aliens ever since we invented TV and radio.

    However in recent years, astronomers, artists, linguists and anthropologists have been converging on the idea that creating comprehensible messages for aliens is much harder than it seems. This week, Paterson and others discussed the difficulties of talking to our cosmic neighbours at a conference called Communicating Across the Cosmos, held by SETI (Search for Extraterrestrial Intelligence). It seems our traditional ways of communicating through pictures and language may well be unintelligible – or worse, be catastrophically misconstrued. So how should we be talking to ET?

    Lost in translation?

    We have always wanted to send messages about humanity beyond the planet. According to Albert Harrison, a space psychologist and author of Starstruck: Cosmic Visions in Science, Religion and Folklore, the first serious designs for contacting alien life appeared two centuries ago, though they never got off the ground.

    In the 1800s, mathematician Carl Gauss proposed cutting down lines of trees in a densely forested area and replanting the strips with wheat or rye, Harrison wrote in his book. “The contrasting colours would form a giant triangle and three squares known as a Pythagoras figure which could be seen from the Moon or even Mars.” Not long after, the astronomer Joseph von Littrow proposed creating huge water-filled channels topped with kerosene. “Igniting them at night showed geometric patterns such as triangles that Martians would interpret as a sign of intelligence, not nature.”

    Odours needn’t be pleasant – the smell of gasoline, for instance, could hint at our reliance on fossil fuels (Getty Images)

    But in the 20th Century, we began to broadcast in earnest. The message sent by Arecibo hoped to make first contact on its 21,000 year journey to the edge of the Milky Way. The sketches it contained, made from just 1,679 digital bits, look cute to us today, very much of the ‘Pong’ video game generation. Just before then, NASA’s Pioneer 10 and 11 space probes each carried a metal calling card bolted onto their frame with symbols and drawings on the plaque, showing a naked man and woman.

    NASA Pioneer 10
    NASA/Pioneer 10

    Yet it’s possible that these kinds of message may turn out to be incomprehensible to aliens; they might find it as cryptic as we find Stone Age etchings.

    Antique tech

    “Linear drawings of a male and a female homo sapiens are legible to contemporary humans,” says Marek Kultys, a London-based science communications designer. ”But the interceptors of Pioneer 10 could well assume we are made of several separate body parts (i.e. faces, hair and the man’s chest drawn as a separate closed shapes) and our body surface is home for long worm-like beings (the single lines defining knees, abdomens or collarbones.).”

    Man-made tech may also be an issue. The most basic requirement for understanding Voyager’s Golden Record, launched 35 years ago and now way out beyond Pluto, is a record player. Aliens able to play it at 16 and 2/3 revolutions a minute will hear audio greetings in 55 world languages, including a message of ‘Peace and Friendship’ from former United Nations Secretary General Kurt Waldheim. But how many Earthlings today have record players, let alone extraterrestrials?

    Our sights and sounds of Earth might be unintelligible to an alien audience (NASA, Pioneer)

    What if the aliens we’re trying to talk to are utterly different from us, physically and mentally? What if alien life is like the type encountered in Stanislav Lem’s Solaris, for instance, where a planet is surrounded by an intelligent ocean. The ocean itself is the alien being, a disembodied mind.

    “Supposing an “alienish” speaking human wished to explain the whole concept of sexual reproduction to a homogenous sentient ocean, would there be any chance for the human to become understood?” says Kultys. “Sharing the same context is essential for comprehension.”

    Time capsule

    Inevitably such messages become outdated too, like time capsules. Consider the case of the Oglethorpe Atlanta Crypt of Civilization – a time capsule sealed on Earth in 1940, complete with a dry martini and a poster of Gone With the Wind. It was intended as a snapshot of 20th Century life for future humans, not aliens, but like an intergalactic message, may only give a limited picture to future generations. When, in 61,000 years, the Oglethorpe time capsule is opened, would Gone With The Wind have stood the test of time?

    Oglethorpe Atlanta
    Oglethorpe Atlanta Crypt of Civilization interior

    This message was taken into the stars by Pioneer – but we have no idea if aliens would be able to understand it (Nasa)

    Kultys argues that all these factors should be taken into account when we calculate the likelihood of communicating with intelligent life. The astronomer Frank Drake’s famous equation de allows anyone to calculate how many alien species are, based on likely values of seven different factors. At a UK Royal Society meeting in 2010 Drake estimated there are roughly 10,000 detectable civilisations in the galaxy. Yet Kultys points out that we should also factor in how many aliens are using the same channel of communications as us, are as willing to contact us as we are them, whose language we hope to learn, and who are physically similar to us.

    Another barrier we might consider is the long distance nature of trans-cosmos communication. It means that many years ‒ even a thousand ‒ could pass between sending a message and receiving a reply. Paterson sees romance in that. “Our hope for communication with another intelligent civilisation has a melancholic aspect to it. We are on an island in a vast, dark space. Imagine if communication… became like an exchange of perfumed love letters with the quiet agony of expectation… Will we meet? Will we be as the other imagined? Will the other be able to understand us?”

    Ready for an answer?

    Anthropologist John Traphagan of the University of Texas in Austin has been asking the same question, though his view is more cautious. “When it comes to ET, you’ll get a signal of some kind; not much information and very long periods between ‘Hi, how are you?’ and whatever comes back. We may just shrug our shoulders and say ‘This is boring’, and soon forget about it or, if the time lag wasn’t too long, we might use the minimal information we get from our slow-speed conversation to invent what we think they’re like and invent a kind concept of what they’re after.”

    The aliens in Independence Day (1996) did not come in peace (20th Century Fox)

    While we have been sending out messages, we have not been preparing the planet for what happens when we get an interstellar return call. First contact could cause global panic. We might assume those answering are bent on galactic domination or, perhaps less likely, that they are peaceful when in fact they’re nasty.

    Consider how easy it is to mess up human-to-human communications; I got Traphagan’s first name wrong when I e-mailed him for this article. An apology within minutes cleared up the confusion, yet if he had been an alien anthropologist on some distant planet it would have taken much longer to fix. He later confessed: “I could have thought this is a snooty English journalist and our conversation might never have happened.”

    Even if Earth’s interstellar messaging committees weeded out the typos, cultural gaffes are always a possibility. These can only be avoided by understanding the alien’s culture – something that’s not easy to do, especially when you’ve never met those you’re communicating with.

    Rosy picture

    So, what is the best way to communicate? This is still up for grabs – perhaps it’s via smell, or some other technique we haven’t discovered yet. Clearly, creating a message that is timeless, free of cultural bias and universally comprehensible would be no mean feat.

    But for starters, being honest about who we are is important if we want to have an extra-terrestrial dialogue lasting centuries, says Douglas Vakoch, director of interstellar message composition at Seti. (Otherwise, intelligent civilisations who’ve decoded our radio and TV signals might smell a rat.)

    The golden discs aboard the Voyager spacecraft require aliens to understand how to play a record (NASA)

    “Let’s not try to hide our shortcomings,” says Vakoch. “The message we should send to another world is straightforward: We are a young civilisation, in the throes of our technological adolescence. We’re facing a lot of problems here on Earth, and we’re not even sure that we’ll be around as a species when their reply comes in. But in spite of all of these challenges, we humans also have hope – especially hope in ourselves.”

    Voyager’s Golden Record paints a rosy picture of humanity. It doesn’t mention our wars or famines, Earth’s pollution or nuclear explosions. According to Traphagan, any aliens who came to Earth on the basis of that would say: “Hey, I thought this was a really nice place but they’ve polluted the crap out of it.”

    Yet ultimately what matters, says Paterson, is that they stop and consider the beings who sent them a message; the people who wanted to say: “Here are some important things. Here’s our DNA, here is some maths and universal physics. And here is our longing and desire to say “I’m like you, but I’m different.”

    See the full article here.

    ScienceSprings relies on technology from

    MAINGEAR computers



  • richardmitnick 9:01 am on July 10, 2014 Permalink | Reply
    Tags: , BBC, , , ,   

    From BBC: “LHC scientists to search for ‘fifth force of Nature'” 


    10 July 2014
    Pallab Ghosh

    The next couple of years will be make or break for the next big theory in physics called supersymmetry – SUSY for short. It might make way for a rival idea which predicts the existence of a ‘fifth force’ of nature.

    Next Spring, when the Large Hadron Collider (LHC) resumes its experiments, scientists will be looking for evidence of SUSY. It explains an awful lot that the current theory of particle physics does not. But there is a growing problem, provocatively expressed by Nobel Laureate George Smoot: “supersymmetry has got symmetry and it’s super but there is no experimental data to suggest it is correct.”

    CERN LHC Grand Tunnel
    LHC tunnel

    CERN LHC New
    LHC map

    According to the simplest versions of the theory, supersymmetric particles should have been discovered at the LHC by now. One set of null results prompted Prof Chris Parkes, of the LHCb to quip: “Supersymmetry may not be dead but these latest results have certainly put it into hospital”.

    But other forms of the theory are still very much in play.

    Next year will be an important year for SUSY. The LHC will be smashing atoms together at almost twice the energy it did in its first run. Even those who are still strong advocates of SUSY, such as Cern’s revered professor of theoretical physics, John Ellis, agree that if LHC scientists do not find super particles in the LHC’s second run, it might be time for the hospital patient to be moved to the mortuary.

    “If it is not found in LHC run two then there will be relatively few corners it could hide,” he told BBC News.

    “I know that at that point the community may decide that the guys who predicted supersymmetry are dying off like flies and that young guys will be interested in different types of theories and supersymmetry may be forgotten. But I don’t think we are at that point yet.”
    LHC Tunnel Engineers have spent more than a year upgrading the LHC’s systems. The hope is that this will allow a new realm of physics to be opened up

    One of those young guys is Thibaut Mueller, a 24-year-old PhD student at Cambridge University. He is already checking out alternatives to SUSY.

    “A few years ago we thought it was a case of who will be first to find supersymmetry,” he said.

    “Now there is less and less focus on it and more people are starting to branch out into other models.”

    Mr Mueller’s PhD looks at an alternative to supersymmetry called the composite Higgs model. This idea has been around for decades but is undergoing a resurgence as some researchers raise questions over supersymmetry. Physicists will be looking for evidence for it in the next run of the LHC in 2015.

    Thibault’s colleague Dr Ben Gripaios believes that the Composite Higgs theory is now a serious alternative to supersymmetry.
    Continue reading the main story

    “SUSY was regarded by many people as the perfect theory. We have been looking really hard for it for a long time and we have not found it and so possibly there is a different explanation. For me the most compelling alternative is the Composite Higgs. It is just as plausible as supersymmetry,” he told BBC News.

    The current theory to explain the forces of nature was developed in the 1960s and is called the Standard Model. It elegantly explains how 13 particles, including the Higgs, interact to create three of the four forces of nature: electromagnetism, and the nuclear strong and weak forces.

    The Standard Model of elementary particles, with the three generations of matter, gauge bosons in the fourth column, and the Higgs boson in the fifth.

    But the Standard Model does not explain how gravity works, nor can it account for the [dark] matter and [dark] energy that makes up 95% of the Universe – referred to by physicists as the “Dark Universe”.

    Supersymmetry is an extension of the Standard Model and is an attempt to explain some of the things the current theory can’t.
    Super particles The stage has been set for some years for the detection of super particles. But so far they have been a no show.

    It predicts the existence of so-called superparticles which account for much of the missing mass and energy of the Universe.

    Supersymmetry standard model
    Supersymmetry standard model

    Supersymmetry also neatly solves what physicists describe as the “fine tuning problem”. In very crude terms, all subatomic particles can be thought to have two values for their mass: Their mass in isolation which is called their “bare” mass, and their experimental mass, which includes interactions with other sub-atomic particles.

    For all particles the two masses are about the same, except for the Higgs, whose bare mass must be many times larger than its experimental mass.

    Going from such a relatively big number to a small number is an unlikely occurrence, rather like a skydiver landing on the head of a pin each time they jump out of a plane. It can only happen if there is an overarching force guiding the skydiver on to the pin head – something that physicists call “fine tuning”.

    The existence of superparticles interacting with their normal counterparts fine tunes the Higgs’s two masses perfectly. The drawback though is that there is no evidence of SUSY, at least not yet.

    The composite Higgs theory also solves the fine tuning problem, albeit less elegantly and, just as with SUSY, there is no experimental evidence for it. It supposes that the Higgs is not a fundamental particle, but is instead made up of other fundamental particles bound together by a hitherto unseen fifth force of nature. This is similar to what is already known to happen with the strong nuclear force, which binds quarks together to produce nuclear particles like protons and neutrons.

    Scientists at the LHC hope to detect evidence for one or other theory when they resume their experiments in April. In effect, the starting gun goes off in an invisible two-horse race where the winner emerges only at the finish line. Supersymmetry is still the favourite in the minds of most particle physicists, but Thibaut Mueller thinks that the likelihood of finding evidence for composite Higgs theory is not far behind.

    Why then is this promising youngster gambling his still early career on the outsider?

    High risk

    “This is a high risk, high gain game,” he explained. “If we find either (SUSY or the composite Higgs) this would be the biggest revolution in particle physics and possibly the whole of physics since quantum mechanics in the the 1940s.

    “Even if we do not find evidence for SUSY or composite Higgs, we will still have learned important facts about the Standard Model, which will guide us to new theories”.

    Of course, the researchers may see neither, which raises the possibility that no fine tuning is needed to turn the big Higgs into the little Higgs.

    That would mean that we live in a Universe where the dice are loaded to ensure that the Higgs experimental mass will always improbably land neatly on its bare mass each and every time.

    In the absence of evidence for either theory, this anthropic principle might seem like a tempting option. But it’s one that those on the front line of research vehemently resist.

    According to Thibault Mueller that view is a “conversation stopper”.

    “It says that ‘we are special because we as humans are here to observe it and so we exist’. If we accept that then we might as well give up science altogether.

    “We (have established) that we as a species are not special, the Earth is not special, our Solar System is not special. Now we are saying: ‘Ah! Our Universe is not that special either’.”

    Prof Rolf Dieter Heuer, the director-general of the European Centre for Nuclear Research (Cern) recently told researchers at the International Conference on High Energy Physics (ICHEP) in Valencia, that there was “a lot at stake” for the LHC’s second run starting next year.

    Indeed there is: careers, reputations and deeply cherished ideas.

    But whatever the outcome, physicists are preparing themselves for the ride of their lives. As Prof Heuer told the physics community: “There’s much more to be discovered in the Dark Universe”.

    See the full article here.

    ScienceSprings is powered by MAINGEAR computers

  • richardmitnick 4:53 am on April 12, 2014 Permalink | Reply
    Tags: , , , BBC, , , ,   

    From BBC: “Dark matter hunt: LUX experiment reaches critical phase” 


    8 April 2014
    Rebecca Morelle

    The quest to find the most mysterious particles in the Universe is entering a critical phase, scientists say.

    An experiment located in the bottom of a gold mine in South Dakota, US, could offer the best chance yet of detecting dark matter.

    Scientists believe this substance makes up more than a quarter of the cosmos, yet no-one has ever seen it directly.

    Early results from this detector, which is called LUX, confirmed it was the most powerful experiment of its kind.

    LUX Dark matter

    In the coming weeks, it will begin a 300-day-long run that could provide the first direct evidence of these enigmatic particles.

    Spotting WIMPs

    Beneath the snow-covered Black Hills of South Dakota, a cage rattles and creaks as it begins to descend into the darkness.

    For more than 100 years, this was the daily commute for the Homestake miners searching for gold buried deep in the rocks.

    Today, the subterranean caverns and tunnels have been transformed into a high-tech physics laboratory.

    Scientists now make the 1.5km (1-mile) journey underground in an attempt to solve one of the biggest mysteries in science.

    “We’ve moved into the 21st Century, and we still do not know what most of the matter in the Universe is made of,” says Prof Rick Gaitskell, from Brown University in Rhode Island, one of the principle investigators on Large Underground Xenon (LUX) experiment.

    The LUX detector is located 3km underground – and could be our best hope yet of finding dark matter

    Scientists believe all of the matter we can see – planets, stars, dust and so on – only makes up a tiny fraction of what is actually out there.

    They say about 85% of the matter in the Universe is actually dark matter, so called because it cannot be seen directly and nobody really knows what it is.

    This has not stopped physicists coming up with ideas though. And the most widely supported theory is that dark matter takes the form of Weakly Interacting Massive Particles, or WIMPs.

    Prof Gaitskell explains: “If one considers the Big Bang, 14bn years ago, the Universe was very much hotter than it is today and created an enormous number of particles.

    “The hypothesis we are working with at the moment is that a WIMP was the relic left-over from the Big Bang, and in fact dominates over the regular material you and I are made of.”

    The Homestake gold mine, which has now been converted into a lab, is in the Black Hills of South Dakota

    The presence of dark matter was first inferred because of its effect on galaxies like our own.

    As these celestial systems rotate around their dense centre, all of the regular matter that they contain does not have enough mass to account for the gravity needed to hold everything together. Really, a spinning galaxy should fly apart.

    Instead, scientists believe that dark matter provides the extra mass, and therefore gravity, needed to hold a galaxy together.

    It is so pervasive throughout the Universe that researchers believe a vast number of WIMPs are streaming through the Earth every single second. Almost all pass through without a trace.

    However, on very rare occasions, it is thought that dark matter particles do bump into regular matter – and it is this weak interaction that scientists are hoping to see.

    The LUX detector is one of a number of physics experiments based in the Sanford Underground Research Facility that require a “cosmic quietness”.

    Prof Gaitskell says: “The purpose of the mile of rock above is to deal with cosmic rays. These are high-energy particles generated from outside our Solar System and also by the Sun itself, and these are very penetrating.

    “If we don’t put a mile of rock between us and space, we wouldn’t be able to do this experiment.”

    Inside a cavern in the mine, the detector is situated inside a stainless steel tank that is two storeys high.

    The detector is in housed in a tank that is filled with purified water

    This is filled with about 300,000 litres (70,000 gallons) of ultra-purified water, which means it is free from traces of naturally occurring radioactive elements that could also interfere with the results.

    “With LUX, we’ve worked extremely hard to make this the quietest verified place in the world,” says Prof Gaitskell.

    At the detector’s heart is 370kg (815lb) of liquid xenon. This element has the unusual, but very useful, property of throwing out a flash of light when particles bump into it.

    And detecting a series of these bright sparks could mean that dark matter has been found.

    The LUX detector was first turned on last year for a 90-day test run. No dark matter was seen, but the results concluded that it was the most sensitive experiment of its kind.

    Now, when the experiment is run for 300 days, Prof Gaitskell says these interactions might be detected once a month or every few months.

    The team would have to see a significant number of interactions – between five and 10 – to suggest that dark matter has really been glimpsed. The more that are seen, the more statistical confidence there will be.
    LUX uses light detectors called photomultiplier tubes to record any flashes of light

    However, LUX is not the only experiment setting its sights on dark matter.

    With the Large Hadron Collider, scientists are attempting to create dark matter as they smash particles together, and in space, telescopes are searching for the debris left behind as dark matter particles crash into each other.

    CERN LHC New
    LHC at CERN

    Mike Headley, director of the South Dakota Science and Technology Authority, which runs the Sanford laboratory, says a Nobel prize will very probably be in store for the scientists who first detect dark matter.

    He says: “There are a handful of experiments located at different underground laboratories around the world that want to be the first ones to stand up and say ‘we have discovered it’, and so it is very competitive.”

    Finding dark matter would transform our understanding of the Universe, and usher in a new era in fundamental physics.

    However, there is also a chance that it might not be spotted – and the theory of dark matter is wrong.

    Dr Jim Dobson, based at the UK’s University of Edinburgh and affiliated with University College London, says: “We are going into unknown territory. We really don’t know what we’re going to find.

    “If we search with this experiment and then the next experiment, LUX Zeppelin, which is this much, much bigger version of LUX – if we didn’t find anything then there would be a good chance it didn’t exist.

    He adds: “In some ways, showing that there was no dark matter would be a more interesting result than if there was. But, personally, I would rather we found some.”

    Prof Carlos Frenk, a cosmologist from Durham University, says that many scientists have gambled decades of research on finding dark matter.

    He adds: “If I was a betting man, I think LUX is the frontrunner. It has the sensitivity we need. Now, we just need the data.

    “If they don’t [find it], it means the dark matter is not what we think it is. It would mean I have wasted my whole scientific career – everything I have done is based on the hypothesis that the Universe is made of dark matter. It would mean we had better look for something else.”

    See the full article here.

    ScienceSprings is powered by MAINGEAR computers

  • richardmitnick 5:51 pm on March 10, 2013 Permalink | Reply
    Tags: , , BBC,   

    Brian Cox, BBC Wonders of Life 

    It is no secret in these pages that I believe that Brian Cox, Sir Brian Cox, physicist, teacher, TV darling, is the best thing to happen for Basic Science Research ever.

    Brian was the host of The Big Bang Machine about the LHC at CERN, which was featured here.

    Brian also did the BBC produced Wonders of the Solar System, Wonders of the Universe and so far two series of Stargazing.

    Now comes also from the BBC Wonders of Life, Brian’s latest bit of programming. The program is truly a wonder in itself. Pretty much all of the above you can find on YouTube with some searching.

    Here is the first video in Wonders of Life to get you started.

  • richardmitnick 2:58 pm on February 27, 2013 Permalink | Reply
    Tags: , , , BBC, , ,   

    From BBC: “First glimpse of a black hole’s spin” 

    BBC News

    Astronomers have measured the rate of spin of a supermassive black hole for the first time – and it is big.


    Measurements undertaken with two space-based X-ray telescopes imaged the black hole at the centre of galaxy NGC 1365

    NGC 1635 Credit:ESO

    The spin measurement, published in Nature, gives precious clues as to how the black hole grew and achieved supermassive status.

    Now Guido Risaliti of the Harvard-Smithsonian Center for Astrophysics and colleagues have looked at markedly higher energies – less subject to absorption in those gas layers – using Europe’s XMM-Newton telescope and the recently launched Nu-Star telescope.

    ESA XMM Newton
    ESA XMM Newton

    NASA Nu-Star

    Nustar is unprecedented in its ability to focus in on distant parts of the cosmos in these high-energy X-rays. The results suggest a black hole more than 3 million km across, whose outermost edge is moving at a speed near that of light.”

    Expansion from Lawrence Livermore Lab

    ‘We can trace matter as it swirls into a black hole using X-rays emitted from regions very close to the black hole,’ said Fiona Harrison, NuSTAR principal investigator at the California Institute of Technology, Pasadena, and coauthor of a new study appearing in the Feb. 28 edition of Nature. ‘The radiation we see is warped and distorted by the motions of particles, and by the black hole’s incredibly strong gravity.’

    The formation of supermassive black holes is thought to mirror the formation of the galaxy itself, since a fraction of all the matter drawn into the galaxy finds its way into the black hole. Because of this, astronomers are interested in measuring the spin rates of black holes in the hearts of galaxies.

    The observations also are a powerful test of Einstein’s theory of general relativity, which holds that gravity can bend light and space-time. The X-ray telescopes detected these warping effects in the most extreme of environments, where the immense gravity field of a black hole is severely altering space-time.

    NuSTAR and XMM-Newton simultaneously observed the two-million-solar-mass supermassive black hole lying at the dust and gas-filled heart of a galaxy called NGC 1365. The results showed that the black hole is spinning close to the maximal rate allowed by Einstein’s theory of gravity.”

    See the full article here.

  • richardmitnick 2:43 pm on February 20, 2013 Permalink | Reply
    Tags: , , , BBC,   

    From BBC: “Exoplanet Kepler 37b is tiniest yet – smaller than Mercury” 

    BBC News

    20 February 2013
    Jason Palmer

    Astronomers have smashed the record for the smallest planet beyond our Solar System – finding one only slightly larger than our Moon.


    To spot the tiny, probably rocky planet, they first needed to precisely measure the size of its host star. They did so using astroseismology – effectively, turning tiny variations in the star’s light into sounds. A report in Nature describes the blistering, probably rocky planet, which orbits its star in just 13 days.

    It is joined in this far-flung solar system by two other planets, one three-quarters Earth’s size and one twice as large as Earth. The record for smallest exoplanet is routinely being broken, as astronomers get better and better at finding them.

    The best tool in the planet-hunters’ toolbox is the Kepler space telescope, which stares at a fixed part of the sky, trying to detect the tiny dips in stars’ light that happens when planets pass in front of them: what is called a transit event.

    NASA Kepler Telescope
    NASA Kepler

    In its earliest days, the Kepler team tended to find large planets – Jupiter- and Neptune-sized behemoths. In more recent years, the catalogue of exoplanet has seen an increasing number of so-called super-Earths, up to about twice the radius of our planet. Only recently has something definitively Earth-sized been found. But the new find is a planet just a third the size of that recent record-holder, smaller even than our Solar System’s smallest planet, Mercury.

    ‘I think it’s an amazing technological achievement to be able to be able to detect small rocks like this,’ said Francois Fressin, a co-author of the paper based at the Harvard-Smithsonian Center for Astrophysics.’It means we’re really in the arena where it’s possible to detect all the planets of our Solar System, but around other stars,’ he told BBC News.”

    See the full article here.

  • richardmitnick 12:31 pm on February 18, 2013 Permalink | Reply
    Tags: , , , , BBC, ,   

    From BBC: “Alpha Magnetic Spectrometer to release first results” 

    BBC News

    18 February 2013
    Jonathan Amos

    The scientist leading one of the most expensive experiments ever put into space says the project is ready to come forward with its first results.
    The Alpha Magnetic Spectrometer (AMS) was put on the International Space Station to survey the skies for high-energy particles, or cosmic rays. Nobel Laureate Sam Ting said the scholarly paper to be published in a few weeks would concern dark matter.

    Alpha Magnetic Spectrometer

    This is the unseen material whose gravity holds galaxies together. Researchers do not know what form this mysterious cosmic component takes, but one theory points to it being some very weakly interacting massive particle (or Wimp for short).

    The Massachusetts Institute of Technology professor said the project he first proposed back in the mid-1990s had now reached an important milestone. ‘We’ve waited 18 years to write this paper, and we’re now making the final check,’ he told reporters.’I would imagine in two or three weeks, we should be able to make an announcement.’

    Although telescopes cannot detect the Wimp, there are high hopes that AMS can confirm its existence and describe some of its properties from indirect measures.

    Alpha Magnetic Spectrometer (AMS-02) is a state-of-the-art particle physics detector constructed, tested and operated by an international team composed of 60 institutes from 16 countries and organized under United States Department of Energy (DOE) sponsorship. The AMS-02 will use the unique environment of space to advance knowledge of the universe and lead to the understanding of the universe’s origin by searching for antimatter, dark matter and measuring cosmic rays.

    See the full BBC article here.

Compose new post
Next post/Next comment
Previous post/Previous comment
Show/Hide comments
Go to top
Go to login
Show/Hide help
shift + esc

Get every new post delivered to your Inbox.

Join 455 other followers

%d bloggers like this: