New Attempt for a 'Unified Theory of Everything'

When it comes to explaining the world around us, there are two ways you can go about it. You can either explain how large bodies interact, as in everything from apples and humans to planets and galaxies, or determine the behavior of extremely small, elementary particles, such as photons and electrons. General relativity, as a theory, is extremely apt at explaining large-scale interactions, whereas quantum mechanics is perfectly able to show how particles interact at a subatomic level. Connecting the two would result in a Unified Theory of Everything that would essentially explain everything.

But drawing parallels between the two theories proves to be extremely difficult to do, considering the fact that, when you get down to it, they report to space and time in completely different ways. While general relativity (Einstein's theory) sees the space-time continuum as an ocean, a never-ending interaction of particles, quantum mechanics view it as the grains of sand on a beach. The latter theory estimates that the “grains” making up space and time may be measuring as little as 10^-35 meters. Such a small size puts these grains far beyond the capabilities of any Earth-based instrument.

Physicists believe that one possible solution to testing whether the theories are accurate is to look at gamma-rays, the extremely energetic forms of light that are believed to be created by extreme and very rare astronomical events, such as colliding neutron stars and supermassive black hole emissions. The experts explain that higher energies for the photons in these radiations mean shorter wavelengths. This means, some argue, that the photons could start stumbling over and colliding with the fine space-time particles at some point, which may slow down their amazing speed, even if by a little bit.

“What you need is really a race,” University of Rome La Sapienza theoretical physicist Giovanni Amelino-Camelia says. He reveals that shorter-wavelength gamma-rays may be made to travel slower than their longer-wavelength counterparts. The main element that dictates the difference may be the existence of the fine grains making up space and time. Details of this amazing idea appear in the October 28 issue of the respected scientific journal Nature.

One of the best bets that we have at finding these gamma-rays is the Fermi Gamma-ray Space Telescope, which is especially suitable for this type of observations. On May 10, it discovered a short gamma-ray burst, from a galaxy some seven billion light-years away from Earth. The shortest-wavelength radiation arrived at the observatory some 0.829 seconds after the longer-wavelength one, but this difference is not nearly enough to support the quantum interpretation. More studies are needed before a clear conclusion can be drawn, Nature News reports.