We'll Be Able to Detect Alien Spaceships Coming at Near-Light Speed

Monday, 30 March 2015 - 2:27PM
Alien Life
Monday, 30 March 2015 - 2:27PM
We'll Be Able to Detect Alien Spaceships Coming at Near-Light Speed
If intelligent aliens ever manage to find Earth, they would need to achieve interstellar travel. Although human technology has not yet achieved this feat, scientists have long contended that it should be possible at nearly the speed of light. But would it even be possible to detect a spaceship moving that fast? A new study says yes, as the interaction between the spaceship and photons should make the spaceship detectable using current technologies.

According to the study, spaceships traveling at relativistic velocities, or near-light speeds, will interact with photons in the cosmic microwave background. This interaction causes a "drag," which limits how fast a spaceship can travel through the medium, but it also creates a distinctive radiation signature that should be detectable by current astrophysical observatories.

From the paper: "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 photons from an ultra-relativistic object may create radiation with a characteristic signature allowing the detection of such objects at large distances."

Of course the study is not strictly relevant yet, as scientists aren't sure that near-light speed travel is even possible, but it could be relevant if there are alien civilizations are far more advanced than we are. This study is a little discouraging in a way, as it makes it less likely that we have been visited without our knowledge, but it's encouraging in the sense that we will probably know when and if it happens in the future. 

Via MIT Technology Review.
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