2015/03/13 by Yurtsever, Ulvi, Wilkinson, Steven · 1 citation
#FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #Popular Physics (physics.pop-ph)
paper · doi:10.48550/arxiv.1503.05845
While special relativity imposes an absolute speed limit at the speed of light, our Universe is not empty Minkowski spacetime. The constituents that fill the interstellar/intergalactic vacuum, including the cosmic microwave background photons, impose a lower speed limit on any object travelling at relativistic velocities. Scattering of cosmic microwave phtotons from an ultra-relativistic object may create radiation with a characteristic signature allowing the detection of such objects at large distances.