“Fast radio bursts” have been confusing astronomers and astrophysicists for a decade — since they were first discovered in 2007. Basically, they’re absurdly powerful pulses of radio waves, only lasting milliseconds, if that. We only discovered them in 2007 because our gear finally became good enough to spot them. But as to what they are, nobody has had any idea.
Now two respectable scientists have a theory: aliens. To be fair, Harvard astrophysicists Avi Loeb and Manasvi Lingam, just wanted to develop a reasonable theory for intelligent life creating the bursts so that their colleagues could rule it out as a possibility. Yes, this is how annoyed astrophysicists are that we keep asking them about aliens. But it’s also reasonable, because something that powerful is usually a sign of a disaster in space: A star getting eaten by a black hole, a supernova, a host of other interstellar phenomena you want to be far, far away from. Astronomers haven’t found evidence for any of these events creating the bursts, nor do they have a solid explanation for why the bursts repeat.
Loeb and Lingam essentially asked themselves two questions: One, if these bursts were generated by intelligent life, how big and powerful would it have to be? And two, if they were building a huge radio transmitter, why would they bother in the first place? Interestingly, Loeb and Lingam determined that it was possible to build what amounts to a giant radio pulse generator. Granted, by our standards, it’s ridiculous: It takes all the solar energy that would fall on a planet twice the size of Earth, meaning that once again, we’ve got a theory involving aliens encasing stars in giant solar arrays. But building it is not only possible, it’s within reason of known engineering technology.
The scientists even offered a practical answer both to why it’s being built and why we only see glimpses of it:
They argue that the most plausible use of such power is driving interstellar light sails. To power a light sail, the transmitter would need to focus a beam on it continuously. Observers on Earth would see a brief flash because the sail and its host planet, star and galaxy are all moving relative to us. As a result, the beam sweeps across the sky and only points in our direction for a moment.
This isn’t solid proof. As we said, the idea was to develop a workable hypothesis so that other wicked smart people could shoot it down and figure out what they think is really happening. Of course, if they can’t shoot it down, that’s when things start getting interesting.
(via Universe Today)