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, @06:22PM
So how would a wormhole or space bending travel signature look like? That seems so far the only realistic option to crack the distances in space.
(Score: 2) by HiThere on Saturday April 11 2015, @07:08PM
I don't think a wormhole would leave a detectable signal in the middle. There is the problem that it takes a lot of negative mass to stabilize it, though. (Or is that mass with negative energy?) And I'm not sure what you mean by "space bending" singe I don't think you mean "artificial gravity" which if used to propel the spaceship would leave an identical trail to any other propulsion method...though granted each propulsion method has a few special characteristics of its own.
FWIW, my idea of the best way to do interstellar space is a generation ship...except that thinking of it as a ship is wrong. Instead think of it as a mobile habitat. That way you don't need any huge amount of power (anything that gets you into the region of time dilation is horribly expensive) and you don't need to reach any particular destination at any particular time. You live by browsing off of free planets, asteroids, etc. You *do* need controlled fusion and a well regulated nearly closed ecosystem. (You *might* be able to do this with fission, but it's iffy.)
Javascript is what you use to allow unknown third parties to run software you have no idea about on your computer.
(Score: 2) by kaszz on Saturday April 11 2015, @07:30PM
Space bending is that you contract space ahead of your ship and expand it behind you. And the ship itself remains static inside a bubble.
Your are probably right about the wormhole. No detection signature in mid path.
Overall there might be signs of intelligent activities however which in itself would be interesting. If the scientific community wouldn't limit themselves to radio waves only.
(Score: 2) by boristhespider on Saturday April 11 2015, @10:18PM
No-one limits to themselves to radio waves! I'm not sure where that idea comes from. Any astronomer wants to cover as much of the spectrum as we possibly can! Gamma ray bursts are a nice example of an intriguing problem that comes up because telescopes (initially spy telescopes, entertainingly, but followed up with astronomical telescopes once the Americans and Russians were convinced they weren't trying to kill each other) observe in gamma rays. Vast amounts of astronomy is even now done in optical, galactic physics relies to a large extent on infra-red (since it can see past the typical dust grains, whose size is such that they fuck up optical observations), then obviously we also need radio wave astronomy even though without massive interferometers the resolution is diabolical, and my own field in cosmology relies to a vast degree on microwave observations.
Frankly what we want is all-sky surveys in every single wavelength. Realistically, we're never getting that. But mass surveys in the microwave (such as Planck), along with mass surveys in radio (such as SKA will bring) and mass surveys in the IR/optical (such as SDSS) along with whatever we can glean in the X/gamma ray regime, gives us good leverage, especially as in these broad fields we can also observe in narrower frequency bands.
(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.
(Score: 2) by boristhespider on Saturday April 11 2015, @10:14PM
To be honest a wormhole would look like a black hole. I'd like to take volunteers to throw themselves into a black hole in the hope it's a wormhole inside.
Warp would be a lot more interesting. Assuming we're talking about warp solutions in relativity, if a warping spaceship were coming towards you I'd guess you'd get a high blueshifting of matter lying between you and the ship, and a corresponding redshifting behind which would be extreme closer to the ship and increasingly mild further away. (Warp solutions typically have a tight bunching of space and a long tail.) These effects would obviously be affecting different objects lying between you and the ship and would then die away - it would be extremely characteristic. There are two timescales involved (from the observer's perspective) - the time between the start and end of the effect, and the rate at which intermediate objects start to blueshift, blueshift strongly, move back towards neutral, start to redshift, redshift strongly, and then move slowly back towards neutral. The latter would give you an idea of what we may as well for want of a better word dub the "velocity" of the ship, while the former would then allow you to determine where the ship was when it kicked its drive in. If the drive were hard enough, those blueshifted photons could be whacked into the X ray or gamma ray range, at which point we'd want to make sure we weren't in it's path. The Enterprise blasting towards you at Warp 9 could be a lethal weapon...
(Score: 2) by kaszz on Saturday April 11 2015, @10:21PM
So if we find electromagnetically shifted trails across the sky.. *hmm!!*
(Score: 2) by boristhespider on Saturday April 11 2015, @10:42PM
It would be a good day :)