Cool!Enki wrote:http://web.mit.edu/newsoffice/2012/mit- ... -1219.html
MIT Researchers discover a new state of matter, Quantum Spin Liquid.
It may sound less likely than hell freezing over, but physicists have created an atomic gas with a sub-absolute-zero temperature for the first time.
Their technique opens the door to generating negative-Kelvin materials and new quantum devices, and it could even help to solve a cosmological mystery.
http://link.springer.com/content/pdf/10 ... 012-5603-3Abstract
We have found that the current practical Newtonian formula for the gravity tide of the Earth implies a hypothesis that gravity travels at the speed of light; furthermore, we have derived and solved the propagation equation of gravity using the observation data of Earth tides from Shiquanhe and Wushi, after correction of phase lag due to the anelasticity of the Earth, and found that the speeds of gravity are from 0.93 to 1.05 times the speed of light with a relative error of about 5%. This provides first set of strong evidences to show that the speed of gravity is the same as the speed of light.
This article is published with open access at Springerlink.com
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Einstein A. The Meaning of Relativity. 5th ed. Princeton, NJ: Princeton University Press, 1954
Hartle J B. Gravity: An Introduction to Einstein’s General Relativity. San Francisco: Addison Wesley, 2008
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Ohanian H C, Ruffini R. Translated by Xiang S P, Feng L L. Gravitation and Spacetime (in Chinese). Beijing: Science Press, 2006
Melchior P. The Tides of Planet Earth. New York: Pergamon Press, 1978
Agnew D C. Earth tides. In: Herring T, ed. Treatise on Geophysics. Oxford: Elsevier, 2007. 163–195 CrossRef
Tang K Y, Zhang H, Wang Q, et al. Gravity effects of solar eclipse and inducted gravitational field. In: American Geophysical Union, Fall Meeting 2003, abstract #G32A-0735
Tang K Y. The retarded gravitation and paleogravity. In: 27th General Assembly of International Astronomy Union, Rio de Janeiro, Brazil, 2009. 44–45
Tang K Y. Total solar eclipse and the pendulum challenging Einstein. Chin Natl Astron, 2009, 11: 40–45
Tang K Y. Observational evidences on the speed of gravity (in Chinese). In: Report in the Annul Meeting for the Commission of Gravity and Relativistic Astrophysics of Chinese Society of Physics, Shijiazhuang, China, 2010
Tang K Y. Observational evidences to show that gravitational field travels at the speed of light. In: 2010 International Workshop on Gravitational Waves Detection with Atom Interferometer, Hangzhou, China, 2010
Tang K Y, Wen W, Hua C C, et al. Observational evidences for the propagation speed of gravity. In: 28th General Assembly of International Astronomy Union, Beijing, China, 2012. 938–939
Ray R D, Eanes R J, Chao B F. Detection of tidal dissipation in the solid Earth by satellite tracking and altimetry. Nature, 1996, 381: 595–597 CrossRef
Ray R D, Eanes R J, Lemoine F G. Constraints on energy dissipation in the Earth’s body tide from satellite tracking and altimetry. Geophys J Int, 2001, 144: 471–480 CrossRef
Arabelos D. Comparison of Earth-tide parameters over a large latitude difference. Geophys J Int, 2002, 151: 950–956 CrossRef
Sun H P, Xu H Z, Zhou J C, et al. Latest observation results from superconducting gravimeter at station Wuhan and investigation of the ocean tide models (in Chinese). Chin J Geophys, 2005, 48: 299–307
Xu J Q, Sun H P, Zhou J C. Experimental detection of the inner core translational triplet. Chin Sci Bull, 2010, 55: 276–283 CrossRef
Xu J Q, Chen X D, Zhou J C, et al. Characteristics of tidal gravity changes in Lhasa, Tibet, China. Chin Sci Bull, 2012, 57: 2586–2594
A field that permeates the universe and gives rise to a new force, or "fifth force," between massive objects may be a candidate for dark energy and an explanation for why the expansion of the universe is accelerating. This field, called the symmetron field, is so named because it has a symmetry in regions of high density, while in regions of low density, such as a vacuum, the symmetry is broken and the field mediates the new force.
Thus far they have shown promise but if anything their production value has not been proven.Enki wrote:Graphene Supercapacitors
Combining the best of batteries and capacitors. High storage, fast charge.
http://www.upworthy.com/see-the-scienti ... -battery-l
Cosmos may be 'inherently unstable'
Comments (584)
Jonathan Amos By Jonathan Amos Science correspondent, BBC News, Boston
Particle tracks Collisions at the LHC in Geneva have refined a mass for the Higgs-like particle
Scientists say they may be able to determine the eventual fate of the cosmos as they probe the properties of the Higgs boson.
A concept known as vacuum instability could result, billions of years from now, in a new universe opening up in the present one and replacing it.
It all depends on some precise numbers related to the Higgs that researchers are currently trying to pin down.
A "Higgs-like" particle was first seen at the Large Hadron Collider last year.
Associated with an energy field that pervades all space, the boson helps explain the existence of mass in the cosmos. In other words, it underpins the workings of all the matter we see around us.
Since detecting the particle in their accelerator experiments, researchers at the Geneva lab and at related institutions around the world have begun to theorise on the Higgs' implications for physics.
One idea that it throws up is the possibility of a cyclical universe, in which every so often all of space is renewed.
"It turns out there's a calculation you can do in our Standard Model of particle physics, once you know the mass of the Higgs boson," explained Dr Joseph Lykken.
"If you use all the physics we know now, and you do this straightforward calculation - it's bad news.
"What happens is you get just a quantum fluctuation that makes a tiny bubble of the vacuum the Universe really wants to be in. And because it's a lower-energy state, this bubble will then expand, basically at the speed of light, and sweep everything before it," the Fermi National Accelerator Laboratory theoretician told BBC News.
Exotic but useful metals such as tantalum and titanium are about to become cheap and plentiful
ALUMINIUM was once more costly than gold. Napoleon III, emperor of France, reserved cutlery made from it for his most favoured guests, and the Washington monument, in America’s capital, was capped with it not because the builders were cheapskates but because they wanted to show off. How times change. And in aluminium’s case they changed because, in the late 1880s, Charles Hall and Paul Héroult worked out how to separate the stuff from its oxide using electricity rather than chemical reducing agents. Now, the founders of Metalysis, a small British firm, hope to do much the same with tantalum, titanium and a host of other recherché and expensive metallic elements including neodymium, tungsten and vanadium.
Three body galleryIt's the sort of abstract puzzle that keeps a scientist awake at night: Can you predict how three objects will orbit each other in a repeating pattern? In the 300 years since this "three-body problem" was first recognized, just three families of solutions have been found. Now, two physicists have discovered 13 new families. It's quite a feat in mathematical physics, and it could conceivably help astrophysicists understand new planetary systems.
Very interesting. Thanks.Typhoon wrote:New solutions to one of the oldest problems in physics:
Science | Physicists Discover a Whopping 13 New Solutions to Three-Body Problem
Three body galleryIt's the sort of abstract puzzle that keeps a scientist awake at night: Can you predict how three objects will orbit each other in a repeating pattern? In the 300 years since this "three-body problem" was first recognized, just three families of solutions have been found. Now, two physicists have discovered 13 new families. It's quite a feat in mathematical physics, and it could conceivably help astrophysicists understand new planetary systems.
CURSE you, EINSTEIN! Humanity still chained in relativistic PRISON
'Collapsar jump' from Forever War seemingly not on cards
By Lewis Page • Get more from this author
Posted in Science, 26th April 2013 13:54 GMT
Free whitepaper – Hands on with Hyper-V 3.0 and virtual machine movement
Disappointing news on the science wires today, as new research indicates that a possible means of subverting the laws of physics to allow interstellar travel apparently doesn't work.
Curses! Can nothing pierce this damned rubber sheet?
As we are told in a new paper just published in hefty boffinry mag Science:
Neutron stars with masses above 1.8 solar masses possess extreme gravitational fields, which may give rise to phenomena outside general relativity.
That would be quite handy, as one of the rules of general relativity is that nothing can travel faster than light: which means that journeys between the stars must take years or centuries at minimum, and that humanity is probably imprisoned in the immediate vicinity of our home Sun - a tiny pinprick of space on the vast canvas of the universe.
But with the aid of a handy neutron star - aka collapsar, as such bodies consist of collapsed matter in which all the atoms have been crushed down into an unfeasibly incrediblo-dense blob of neutrons - one might perhaps violate Einsteinian physics and so somehow permit human beings to travel the wider universe. Science fiction writer Joe Haldeman speculated to this effect in his classic work The Forever War, in which starships would leap across the galaxy by means of the "collapsar jump":
They had discovered the collapsar jump. Just fling an object at a collapsar with sufficient speed, and it pops out in some other part of the galaxy. It didn't take long to figure out the formula that predicted where it would come out: it travels along the same "line" (actually an Einstein geodesic) it would have followed if the collapsar hadn't been in the way - until it reaches another collapsar field, whereupon it reappears, repelled with the same speed at which it approached the original collapsar. Travel time between the two collapsars ... exactly zero.
But our crew of physicists writing in Science are having simply none of this. They've found a powerful collapsar named PSR J0348+0432, and cunningly managed to measure the effects of its outrageously powerful space-warping gravitational field by monitoring the behaviour of an orbiting "lightweight dwarf" star.
Disappointingly, it seems that even this brutal mangling of the space-time continuum is not enough to suspend Einsteinian physics. The scientists write:
For these masses and orbital period, general relativity predicts a significant orbital decay, which matches the observed value ...
The consistency of the observed orbital decay with general relativity therefore supports its validity, even for such extreme gravity-matter couplings, and rules out strong-field phenomena predicted by physically well-motivated alternatives.
So much for the collapsar jump, then.
"The observations disprove these alternatives and thus give further confidence that Einstein's theory is a good description of nature," says spoilsport astronomer Marten van Kerkwijk of Toronto uni, one of the investigating boffins.
However he leaves us a tiny bit of hope, adding:
" – even though we know it is not a complete one, given the unresolved inconsistencies with quantum mechanics."
PhyOrg | Physics team entangles photons that never coexisted in timeAzrael wrote:the Future of Photons
In the back corner of the optics lab in the Physics/Astronomy Building sits a contraption made of mirrors, crystals, and lasers. In this small corner, Professor John Cramer is experimenting with receiving messages before they’re sent — essentially, time travel.
Cramer’s experiment involves quantum nonlocality, a theory where two quantum-entangled photons can have faster-than-light communication.
To test this theory, a photon from a violet laser is shot at a nonlinear crystal, making two infrared photons. Then the resulting quantum-entangled, daughter-photons go through a beam-splitting crystal and through interferometers that measure the particle’s properties — whether wave-like interference or particle-like path.
By introducing a delay in the sending end of the link, Cramer hopes to be able to detect changes at this subatomic level before the measurements of the second particle have been taken — in essence sending the message from one photon to the other backward through time to be received before it was sent.
More on Retrocausality
Presented and narrated by physicist Brian Green. Join Brian Greene on a wild ride into the weird realm of quantum physics, which governs the universe on the tiniest of scales. Greene brings quantum mechanics to life in a nightclub like no other, where objects pop in and out of existence, and things over here can affect others over there, instantaneously and without anything crossing the space between them. A century ago, during the initial shots in the quantum revolution, the best minds of a generation—including Albert Einstein and Niels Bohr—squared off in a battle for the soul of physics. How could the rules of the quantum world, which work so well to describe the behavior of individual atoms and their components, conflict so dramatically with the everyday rules that govern people, planets, and galaxies?
Quantum mechanics may be counterintuitive, but it's one of the most successful theories in the history of science, making predictions that have been confirmed to better than one part in a billion, while also launching the technological advances at the heart of modern life, like computers and cell phones. But even today, even with such profound successes, the debate still rages over what quantum mechanics implies for the true nature of reality.
