GPS has a new job. It does a great job of telling us our location, but the network of hyper-accurate clocks in space could get a fix on something far more elusive: dark matter.
Dark matter makes up 80 per cent of the universe's matter but scarcely interacts with ordinary matter. A novel particle is the most popular candidate, but Andrei Derevianko ( http://www.dereviankogroup.com/dark-matter-atomic-clocks-idea-call-experimental-efforts/ ) at the University of Nevada, Reno, and Maxim Pospelov ( http://www.perimeterinstitute.ca/people/maxim-pospelov ) at the Perimeter Institute in Waterloo, Ontario, Canada propose that kinks or cracks in the quantum fields that permeate the universe could be the culprit.
If they are right, fundamental properties such as the mass of an electron or the strength of electromagnetic fields would change at the kinks. "The effect is essentially locally modifying fundamental constants," Derevianko says. Clocks would be affected too, measuring time slightly differently as a result.
http://www.newscientist.com/article/dn26575-dark-matter-could-be-seen-in-gps-time-glitches.html
[Abstract/Paper]:
http://arxiv.org/abs/1311.1244
http://www.nature.com/nphys/journal/vaop/ncurrent/full/nphys3137.html
(Score: 2) by maxwell demon on Tuesday November 18 2014, @06:24PM
Err .. .just after hitting "submit" I noticed that in the initial paragraph I omitted a crucial point: Namely that the measurement limit of course depends on how well you can measure. And so does therefore what can be considered "relativistic speed". Atomic clocks (such as those used in GPS) are very accurate measurement devices.
The Tao of math: The numbers you can count are not the real numbers.