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« Image of the Day --"The Kepler 5" --NASA's Short List of Potential Habitable Exoplanets |Main| 'Seeds' of Milky Way's Supermassive Black Hole Discovered »July 20, 2012 New Singularity in Space-Time Found
Einstein’s theory of general relativity explains gravity as a curvature in space-time. But the theory starts from the assumption that any local patch of space-time looks flat, Temple said. But mathematicians at UC Davis "...show that space-time cannot be locally flat at a point where two shock waves collide,” said Blake Temple, professor of mathematics at UC Davis. “This is a new kind of singularity in general relativity.”
A singularity is a patch of space-time that cannot be made to look flat in any coordinate system, Temple said. One example of a singularity is inside a black hole, where the curvature of space becomes extreme.Temple and his collaborators study the mathematics of how shockwaves in a perfect fluid can affect the curvature of space-time in general relativity. In earlier work, Temple and collaborator Joel Smoller, the Lamberto Cesari professor of mathematics at the University of Michigan, produced a model for the biggest shockwave of all, created from the Big Bang when the universe burst into existence.
A shockwave creates an abrupt change, or discontinuity, in the pressure and density of a fluid, and this creates a jump in the curvature. But it has been known since the 1960s that the jump in curvature created by a single shock wave is not enough to rule out the locally flat nature of space-time.*Vogler’s doctoral work used mathematics to simulate two shockwaves colliding, while Reintjes followed up with an analysis of the equations that describe what happens when shockwaves cross. He found this created a new type of singularity, which he dubbed a “regularity singularity.”
What is surprising is that something as mild as interacting waves could create something as extreme as a space-time singularity, Temple said.
Temple and his colleagues are investigating whether the steep gradients in the space-time fabric at a regularity singularity could create any effects that are measurable in the real world. For example, they wonder whether they might produce gravity waves, Temple said.
General relativity predicts that these are produced, for example, by the collision of massive objects like black holes, but they have not yet been observed in nature. Regularity singularities could also be formed within stars as shockwaves pass within them, the researchers theorize.
Moritz Reintjes, Blake Temple, Points of general relativistic shock wave interaction are ‘regularity singularities’ where space–time is not locally flat, Proceedings of the Royal Society A, 2012, DOI: 10.1098/rspa.2011.0360* Zeke Vogler, Blake Temple, Simulation of general relativistic shock wave interactions by a locally inertial Godunov method featuring dynamical time dilation, Proceedings of the Royal Society A, 2012, DOI: 10.1098/rspa.2011.035.
Image below shows thes shock wave around Supernova 1987A captured by the Hubble Space Telescope.
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Image credits: (credit: NASA, ESA, K. France (University of Colordo, Boulder), P. Challis and R. Kirshner (Harvard-Smithsonian Center for Astrophysics)/Wikimedia Commons) and for image at top o fpage with thanks to Jumpjackflash
Posted at 09:45 AM | PermalinkComments
"But mathematicians at UC Davis..."
ROLF! Now it is mathematicians who make discoveries related to physics and cosmology? My goodness, the world gone mad!
Posted by:Roman |July 20, 2012 at 04:36 PMWow Roman, what rock have you been hiding under?? Anyone can look at a picture and imagine what they think they see. Mathematicians have been cyphering for hundreds (even thousands) of years. NOW if we could JUST GET THEM TO DO IT RIGHT!!!! hahahaha
Posted by:mathematician |July 20, 2012 at 07:32 PMRoman, why are you so surprised? Einstein used the same mathematics to deduce from general relativity the predictions which then were confirmed so spectacular (http://en.wikipedia.org/wiki/General_relativity#Consequences_of_Einstein.27s_theory).
mathematician: "Anyone can look at a picture and imagine what they think they see"
Those are physicists.
Posted by:mathematical physicist |July 20, 2012 at 09:36 PMregularity singularity sounds like a small sized yogurt...
Posted by:fj kardatzke |July 21, 2012 at 09:04 AMSigh...that a mathematician is "discovering" is great news. In my view the first to "propose" is philosopers (include in that realm: sci-fi writers); then mathematicians to suggest that something the philosophers posit is theoretically possible. NOW, guys and gals, it's up to you physicists to SHOW it's possible and to show the effects and affects. Then it goes to the engineers to build a working star drive or local gravity field or local anti-gravity field or... (insert your own dream in the elipses).
Now to get around that pesky thing called inertia. Going faster than light is cool, but ending up as star jelly in the process is less so.
Posted by:Deryl |July 21, 2012 at 11:18 AMWhen you can create artificial gravity fields, inertia becomes irrelevant. You are not actually travelling anywhere. The space around you is moving.
Posted by:Matthew |July 21, 2012 at 04:18 PMLast time I'd heard anything about singularities was when the idea was still considered an impossibility just like unicorns and black holes, which from what I can understand at this point, have also been proven to be actual.(Black holes, not unicorns*)I am glad, though that we're doing more research,
though.Does anyone else think that we've left the oceans too obscure, though?
*I wish unicorns were real
Posted by:Gerhardt |July 21, 2012 at 06:48 PMLast time I'd heard anything about singularities was when the idea was still considered an impossibility just like unicorns and black holes, which from what I can understand at this point, have also been proven to be actual.(Black holes, not unicorns*)I am glad, though that we're doing more research,
though.Does anyone else think that we've left the oceans too obscure, though?
*I wish unicorns were real
Posted by:Gerhardt |July 21, 2012 at 06:48 PMMy comments made earlier have not yet appeared on the site. Space and time are homogeneous and continuous. When ever a discontinuity/in homogeneity appears, mass and energy respectively gets generated locally. Such is the intrinsic nature of space and time. Big Bang was the biggest anomaly/singularity to occur that generated the whole universe that subsequently evolved in a logical manner as per the design we note presently. Such is the logic of evolution that we humans are still trying to understand through science. We study how and not why things happen as these do through the sciences we have developed.
Posted by:Narendra Nath |July 22, 2012 at 06:03 AMThe Einstein Field Equations
Quote from: http://archive.ncsa.illinois.edu/Cyberia/NumRel/EinsteinEquations.html#Spherical
“The first person to apply Einstein's general theory was the German astrophysicist Karl Schwarzschild. It was 1916, and the First World War was still raging. Just a few days after reading Einstein's newly published theory while stationed at the Russian front, Schwarzschild began to figure out its consequences for the gravitational fields of stars.
For his first attempt, Schwarzschild simplified the problem by considering a perfectly spherical star at rest, ignoring the effects of the star's interior. He sent his preliminary solution of the star's spacetime curvature to Einstein, who reported the results on Schwarzschild's behalf at a physics meeting in January. The curvature of spacetime predicted by the solution became known as the Schwarzschild geometry and had profound implications on future research into gravitation and cosmology.
A few weeks later, Schwarzschild sent a second paper, this time describing the spacetime curvature inside a star. Tragically, Schwarzschild died a few months later of an illness he contracted while at the Russian front.
Schwarzschild was describing a singularity, a region of infinite spacetime curvature that is postulated to lie within what has more recently been termed a black hole. Einstein considered the "Schwarzschild singularity" and black holes as bizarre constructs, resisting the logic of his own theory right up to his death in 1955.
However, though debate continues on the nature of singularities, since the 1960s there has been mounting indirect evidence that black holes might exist in places where, for example, a collapsed star's intense gravitational field allows nothing, including light, to escape. In that sense, the star disappears from the visible universe and forms what is now called a black hole”, end of quote.
AD: That is: Einstein considered “black holes” and “singularities” to be bizarre – but still modern scientists are using these bizarre and unnatural ideas. Such statements just reveal a lack of dynamical understanding which is suppressed by the ruling one track cosmology of gravity that confuses the scientists.
Something does not appear from nowhere (Big Bang) and disappear to nowhere in some “black hole”, but everything is going in circuits via the natural and basically forces of atmospheric dynamics; thermodynamics; hydrodynamics; electrodynamics; magnetodynamics and nuclear dynamics – that all can act as contracting or expanding forces in a local formation of molecular gas and particles.
Ivar Nielsen
Natural Philosopher
Read also this paper:
"Singularity Predictions of General Relativity":
http://www.olduniverse.com/1,5%20Singularities.pdf
Extract:
""Theoretical doubts [concerning the creation of the universe] are based on the fact that [at the] beginning of the expansion, the metric becomes singular and the density becomes infinite. . . In reality, space will probably be of a uniform character, and the present [relativity] theory will be valid only as a limiting case. . . One may not therefore assume the validity of the equations for very high density of field and of matter, and one may not conclude that the 'beginning of the expansion' must mean a singularity in the mathematical sense. All we have to realize is that the equations may not be continued over such regions."
In this quotation, Einstein stated that his theory could not be used to justify a physical singularity, because his equations would not apply accurately under conditions of extreme density of matter. The thinking of Albert Einstein on such issues is discussed in a recent biography of Einstein, originally written in German by Folsing [6], which states (p. 381):
Posted by:Ivar Nielsen |July 22, 2012 at 06:24 AMAgree with Ivar Nielson about the validity of present day Physics to comprehend understandings about things that happened at or close to Big Bang generation of the Universe. New Physics need to be developed to understand things that happened in early universe. Higg's boson is just a tiny part of it!
Posted by:Narendra Nath |July 23, 2012 at 03:48 AMPost a comment
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