SoylentNews is people
SoylentNews
In an article published on arXiv.org [Full article available] California-based Raytheon engineers Ulvi Yurtsever and Steven Wilkinson say that any interstellar spacecraft traveling at near-light speed would leave distinct light signatures in its wake.
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 traveling at relativistic velocities. Scattering of cosmic microwave photons from an ultra-relativistic object may create radiation with a characteristic signature allowing the detection of such objects at large distances.
(Score: 2) by kaszz on Saturday April 11 2015, @10:29PM
I meant searching for high energy particles (perhaps low ones too?) and other types of energy forms not ordinarily thought of as a means of radiation from objects in the universe. Perhaps there a fields that warps the properties of atoms in other ways. Neutrinos are also interesting from this point of view but also notoriously hard to catch.
(gravity is monitored by LIGO so it's covered)
(Score: 2) by boristhespider on Saturday April 11 2015, @10:38PM
The X and gamma ray observatories are meant to catch the high-energy events, and the microwave and radio surveys should catch practically all the low-energy ones. It's quite hard to come up with something that will emit in these ranges that doesn't have some signal on the CMB, and the CMB is extremely well observed...
But yes, we can always do with more observations, ideally from space so we don't drown ourselves in interference from Jersey Shore and The Only Way is Essex (and the Sun, of course), and across as many frequency ranges as we can hit.
We'd also love to see the cosmic neutrino background. Alas, as you point out, the chances of doing so are extremely slender.