January 11, 2013
Researchers Compare Spacetime To A Smooth Whiskey
April Flowers for redOrbit.com - Your Universe Online
According to new research led by Michigan Technological University, spacetime might be less like a foamy beer and more like a smooth Einsteinian whiskey.Robert Nemiroff and his team studied the tracings of three photons of differing wavelengths to reach this heady conclusion. NASA's Fermi Gamma-ray Space Telescope recorded these tracings in 2009.
About 7 billion light years from Earth, a gamma ray outburst threw the photons from their point of origin.
“Gamma-ray bursts can tell us some very interesting things about the universe,” Nemiroff said in a recent statement.
The data from the Fermi telescope might validate Einstein's view of a smooth spacetime into the realm of quantum mechanics. Einstein described space and time as smooth, deforming only under the weight of matter and energy. According to some quantum gravity theories that deal with matter and energy at the smallest scale, spacetime is made up of the frothy particles. and possibly even black holes that pop in and out of existence over infinitesimally small moments at the so-called Planck-length scale, which is less than a trillionth of a trillionth the diameter of a hydrogen atom.
Bubbles in the foam, assuming they exist all, are almost undetectable because of their tiny size. Scientists have theorized, however, that photons from gamma-ray bursts should be able to track the bubbles' signature.
Gamma-ray burst photon wavelengths are some of the shortest distances known to science. They are so short they should interact with even the even smaller bubbles of quantum foam. If they do interact, the photons should be dispersed on their voyage through frothy spacetime.
The photons should disburse in different ways according to their wavelengths', as in the case of Nemiroff´s three photons. As an example: think of a marble, a bowling ball and a softball taking alternate paths to the same destination.
Very few things can delay gamma-ray photons such as these, so they might travel for unimaginably long distances uninterrupted. The scattering is nearly invisible over short distances, but across 7 billion light years the quantum foam might knock the light around enough to notice. The three photons from the same gamma-ray burst may not have crashed through the Fermi telescope in a dead heat.
Supported by the evidence from the three photons, Nemiroff´s analysis supports earlier indications but takes them clearly below the Planck length. .
“If foaminess exists at all, we think it must be at a scale far smaller than the Planck length, indicating that other physics might be involved,” he says.
“There is a possibility of a statistical fluke, or that spacetime foam interacts with light differently than we imagined,” Nemiroff said.
“If future gamma-ray bursts confirm this, we will have learned something very fundamental about our universe,” added Bradley E. Schaefer, professor of physics and astronomy at Louisiana State University.
For now, at least, this looks like another win for Einstein. Perhaps this calls for a toast!
The findings of this study were presented at the annual meeting of the American Astronomical Society.