Phys.org: Phys.org news tagged with: spacetime
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en-usPhys.org internet news portal provides the latest news on science including: Physics, Nanotechnology, Life Sciences, Space Science, Earth Science, Environment, Health and Medicine.Physicists make first observation of the pushing pressure of light(Phys.org)—For more than 100 years, scientists have debated the question: when light travels through a medium such as oil or water, does it pull or push on the medium? While most experiments have found that light exerts a pulling pressure, in a new paper physicists have, for the first time, found evidence that light exerts a pushing pressure.
http://phys.org/news352437746.html
PhysicsTue, 02 Jun 2015 12:30:01 EDTnews352437746Does time pass? New book says it does—but not in the way you may think"If you walk into a cocktail party and say, 'I don't believe that time passes,' everyone's going to think you're completely insane," says Brad Skow, an associate professor of philosophy at MIT.
http://phys.org/news341649593.html
Other SciencesWed, 28 Jan 2015 06:40:09 EDTnews341649593Artificial spacetime experiment could show tantalizing effects of gravitational waves(Phys.org) —Although the curves and ripples of spacetime are suspected to be full of intriguing secrets about the history of the universe, they are also extremely difficult to study. For this reason, some physicists are turning to the lab to attempt to recreate spacetime geometries where they can be more easily analyzed.
http://phys.org/news324138343.html
PhysicsThu, 10 Jul 2014 09:30:04 EDTnews324138343Liquid spacetime: A very slippery superfluid, that's what spacetime could be likeWhat if spacetime were a kind of fluid? This is the question tackled by theoretical physicists working on quantum gravity by creating models attempting to reconcile gravity and quantum mechanics. Some of these models predict that spacetime at the Planck scale (10-33cm) is no longer continuous – as held by classical physics – but discrete in nature. Just like the solids or fluids we come into contact with every day, which can be seen as made up of atoms and molecules when observed at sufficient resolution. A structure of this kind generally implies, at very high energies, violations of Einstein's special relativity (a integral part of general relativity).
http://phys.org/news317463557.html
PhysicsWed, 23 Apr 2014 09:19:30 EDTnews317463557Fine-tuning Stephen Hawking's theory of mass(Phys.org) —If you want to know your body's mass, you hop on a scale and watch the needle swing. But if you want to know the mass of a region out in space, there's no cosmic equivalent—the best you can do is consult a geometric formula.
http://phys.org/news314340889.html
PhysicsTue, 18 Mar 2014 05:55:27 EDTnews314340889Expanding universe can emerge in remarkably simple way, scientists sayWhen soup is heated, it starts to boil. When time and space are heated, an expanding universe can emerge, without requiring anything like a "Big Bang". This phase transition between a boring empty space and an expanding universe containing mass has now been mathematically described by a research team at the Vienna University of Technology, together with colleagues from Harvard, the MIT and Edinburgh. The idea behind this result is a remarkable connection between quantum field theory and Einstein's theory of relativity.
http://phys.org/news305887548.html
PhysicsTue, 10 Dec 2013 08:46:37 EDTnews305887548Gravity's lingua franca: Unifying general relativity and quantum theory through spectral geometry(Phys.org) —Mathematics is, in essence, an artificial language for precisely articulating theories about the physical world. Unlike natural language, however, translating different classes of mathematics can be difficult at best. Such is the case encountered in the attempt to unify general relativity and quantum theory, since they are expressed in differential geometry and functional analysis, respectively. That being said, spectral geometry – a field in mathematics which concerns relationships between geometric structures of manifolds and spectra of canonically defined differential operators – may resolve this long-standing quandary by allowing spacetime to be treated as simultaneously continuous and discrete, essentially relating the frequency-based ringing of the fabric of spacetime to its manifold-based shape. Recently, scientists at California Institute of Technology, Princeton University, University of Waterloo, and University of Queensland normalized and segmented spectral geometry into small, finite-dimensional steps. They then demonstrated their approach of calculating the shapes of two-dimensional objects from their vibrational spectra as being viable in two, and possibly more, dimensions.
http://phys.org/news286449018.html
PhysicsMon, 29 Apr 2013 11:00:01 EDTnews286449018Shape from sound: New methods to probe the universe(Phys.org) —As the universe expands, it is continually subjected to energy shifts, or "quantum fluctuations," that send out little pulses of "sound" into the fabric of spacetime. In fact, the universe is thought to have sprung from just such an energy shift.
http://phys.org/news284214066.html
PhysicsWed, 03 Apr 2013 13:21:20 EDTnews284214066Gravitational telescope creates space invader mirage(Phys.org)—The NASA/ESA Hubble Space Telescope is one of the most powerful available to astronomers, but sometimes it too needs a helping hand. This comes in the form of Einstein's general theory of relativity, which makes galaxy clusters act as natural lenses, amplifying the light coming from very distant galaxies.
http://phys.org/news281698984.html
Astronomy & SpaceTue, 05 Mar 2013 09:43:14 EDTnews281698984Spacetime ripples from dying black holes could help reveal how they formed(Phys.org)—Researchers from Cardiff University have discovered a new property of black holes: their dying tones could reveal the cosmic crash that produced them.
http://phys.org/news267098187.html
PhysicsMon, 17 Sep 2012 10:56:36 EDTnews267098187Mathematicians offer unified theory of dark matter, dark energy, altering Einstein field equations(Phys.org)—A pair of mathematicians—one from Indiana University and the other from Sichuan University in China—have proposed a unified theory of dark matter and dark energy that alters Einstein's equations describing the fundamentals of gravity.
http://phys.org/news266223577.html
PhysicsFri, 07 Sep 2012 07:59:51 EDTnews266223577Spacetime: A smoother brew than we knew(Phys.org)—Spacetime may be less like beer and more like sipping whisky.
http://phys.org/news264923189.html
Astronomy & SpaceThu, 23 Aug 2012 06:46:44 EDTnews264923189Scientists investigate the possibility of wormholes between stars(PhysOrg.com) -- Wormholes are one of the stranger objects that arise in general relativity. Although no experimental evidence for wormholes exists, scientists predict that they would appear to serve as shortcuts between one point of spacetime and another. Scientists usually imagine wormholes connecting regions of empty space, but now a new study suggests that wormholes might exist between distant stars. Instead of being empty tunnels, these wormholes would contain a perfect fluid that flows back and forth between the two stars, possibly giving them a detectable signature.
http://phys.org/news217858113.html
Astronomy & SpaceFri, 25 Feb 2011 12:09:20 EDTnews217858113Physicists describe method to observe timelike entanglement(PhysOrg.com) -- In "ordinary" quantum entanglement, two particles possess properties that are inherently linked with each other, even though the particles may be spatially separated by a large distance. Now, physicists S. Jay Olson and Timothy C. Ralph from the University of Queensland have shown that it's possible to create entanglement between regions of spacetime that are separated in time but not in space, and then to convert the timelike entanglement into normal spacelike entanglement. They also discuss the possibility of using this timelike entanglement from the quantum vacuum for a process they call "teleportation in time."
http://phys.org/news215095406.html
PhysicsMon, 24 Jan 2011 12:43:40 EDTnews215095406Model describes universe with no big bang, no beginning, and no end(PhysOrg.com) -- By suggesting that mass, time, and length can be converted into one another as the universe evolves, Wun-Yi Shu has proposed a new class of cosmological models that may fit observations of the universe better than the current big bang model. What this means specifically is that the new models might explain the increasing acceleration of the universe without relying on a cosmological constant such as dark energy, as well as solve or eliminate other cosmological dilemmas such as the flatness problem and the horizon problem.
http://phys.org/news199591806.html
PhysicsThu, 29 Jul 2010 06:42:20 EDTnews199591806A Newtonian system that mimics the baldness of rotating black holes(PhysOrg.com) -- The rotating black hole has been described as one of nature's most perfect objects. As described by the Kerr solution of Einstein's gravitational field equations, its spacetime geometry is completely characterized by only two numbers — mass and spin — and is sometimes described by the aphorism "black holes have no hair.''
http://phys.org/news154627589.html
PhysicsMon, 23 Feb 2009 16:06:59 EDTnews154627589