Close

Search

Search Menu
Photonics Media Photonics Buyers' Guide Photonics EDU Photonics Spectra BioPhotonics EuroPhotonics Industrial Photonics Photonics Showcase Photonics ProdSpec Photonics Handbook
More News
share
Email Facebook Twitter Google+ LinkedIn Comments

Is Space a Dispersive Medium?

Photonics Spectra
Apr 2001
According to string theory, perhaps the top contender in the struggle to create a quantum theory of gravity, the vacuum of space is frothing. According to Dimitri V. Nanopoulos, a professor at Texas A&M University in College Station, and his colleagues, John Ellis of CERN in Geneva and Nikolaos E. Mavromatos of King's College in London, these Planck-scale defects in the space-time manifold should produce macroscopic effects over cosmic distances. Namely, the vacuum should be dispersive, so that the speed of light will depend on its frequency.

Research seems to be supporting this position. Physicists interpreting data from the High Energy Gamma Ray Astronomy facility in La Palma, Canary Islands, found that a frequency-dependent speed of light explains the lack of observable electron-positron pairs that should be produced by energetic photons from the galaxy Markarian 501.

GLOSSARY
astronomy
The scientific observation of celestial radiation that has reached the vicinity of Earth, and the interpretation of these observations to determine the characteristics of the extraterrestrial bodies and phenomena that have emitted the radiation.
astronomyBasic ScienceResearch & TechnologyTech Pulse

Comments
Terms & Conditions Privacy Policy About Us Contact Us
back to top

Facebook Twitter Instagram LinkedIn YouTube RSS
©2017 Photonics Media
x Subscribe to Photonics Spectra magazine - FREE!