'Rainbow Gravity' Theory Says Our Universe Has No Beginning - ScientificAmerican/HuffPo
'Rainbow Gravity' Theory Says Our Universe Has No BeginningBy Clara Moskowitz - ScientificAmerican'HuffPo
Posted: 12/10/2013 8:42 am EST
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What if the universe had no beginning, and time stretched back infinitely without a big bang to start things off? That's one possible consequence of an idea called "rainbow gravity," so-named because it posits that gravity's effects on spacetime are felt differently by different wavelengths of light, aka different colors in the rainbow.
Rainbow gravity was first proposed 10 years ago as a possible step toward repairing the rifts between the theories of general relativity (covering the very big) and quantum mechanics (concerning the realm of the very small). The idea is not a complete theory for describing quantum effects on gravity, and is not widely accepted. Nevertheless, physicists have now applied the concept to the question of how the universe began, and found that if rainbow gravity is correct, spacetime may have a drastically different origin story than the widely accepted picture of the big bang.
According to Einstein's general relativity, massive objects warp spacetime so that anything traveling through it, including light, takes a curving path. Standard physics says this path shouldn't depend on the energy of the particles moving through spacetime, but in rainbow gravity, it does. "Particles with different energies will actually see different spacetimes, different gravitational fields," says Adel Awad of the Center for Theoretical Physics at Zewail City of Science and Technology in Egypt, who led the new research, published in October in the Journal of Cosmology and Astroparticle Physics. The color of light is determined by its frequency, and because different frequencies correspond to different energies, light particles (photons) of different colors would travel on slightly different paths though spacetime, according to their energy.
The effects would usually be tiny, so that we wouldn't notice the difference in most observations of stars, galaxies and other cosmic phenomena. But with extreme energies, in the case of particles emitted by stellar explosions called gamma-ray bursts, for instance, the change might be detectable. In such situations photons of different wavelengths released by the same gamma-ray burst would reach Earth at slightly different times, after traveling somewhat altered courses through billions of light-years of time and space. "So far we have no conclusive evidence that this is going on," says Giovanni Amelino-Camelia, a physicist at the Sapienza University of Rome who has researched the possibility of such signals. Modern observatories, however, are just now gaining the sensitivity needed to measure these effects, and should improve in coming years.
The extreme energies needed to bring out strong consequences from rainbow gravity, although rare now, were dominant in the dense early universe, and could mean...
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More: http://www.huffingtonpost.com/2013/12/10/rainbow-gravity-theory-universe-beginning_n_4418017.html?ref=topbar
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This rainbow gravity one is not pleasing to me, and I'm not going to explain why, not with numbers anyways.
The trouble with all these theories is they range from the currently conventional working theory (Big Bang! and all that) to the meh, maybe (like "Rainbow Gravity"
, to the utterly crackpot, like my own.
Personally, I think we are screwed up by our flat-earth biologically directed sense of time as some kind of "fourth dimension" we are traveling through. I don't imagine a universe where time travel, or faster-than-light travel, or anything like that is possible. Everything is light, and light doesn't "see" time.
What I end up with is a universe where only the present exists, and both the "past" and the "future" exist only as possibilities, all divergent from any particular location.
For all we know, there may have been beings like us 13.798 billion years ago who looked up in the sky and saw a universe that still looked like it was 13.798 billion years old.
And maybe 13.798 billion years from now there may be beings like us who look up in the sky and see a universe that still looks like it is 13.798 billion years old. From their perspective we ourselves are living within the Big Bang.
