Of all the unexplained things in our Universe, fast radio bursts are arguably the strangest. They are among the most elusive and explosive signals ever detected in space and although they last only a few milliseconds, they generate as much energy as 500 million Suns. Last year, sixteen of these fast bursts were detected and according to Harvard researchers, these could be proof of advanced alien technology.
Fast bursts (FRB) are not that uncommon. Since the first one detected in 2007, researchers predict that nearly 2,000 of these signals illuminate the Universe every day. But the problem with detecting and analyzing these signals is that they are not only incredibly fleeting (less than 5 milliseconds in duration), but their origins are also hopelessly random. In contrast, earlier in 2016, eleven of these radio signals all came from a single source in a distant Universe. A few weeks ago, six others were detected also coming from the same place and the researchers managed to identify their location in a faint dwarf galaxy more than three billion light years from Earth. But where exactly do they come from?
» Fast bursts are extremely bright. Given their short duration and their very distant origins, we cannot identify with certainty a natural source. says theoretical physicist Avi Loeb of the Harvard-Smithsonian Center for Astrophysics. » We must think about an artificial origin and try to verify it « .
Despite identifying collective sources of these radio signals, no one is able to date to provide a convincing explanation as to the origin of these powerful explosions. The main hypotheses at present suggest that these signals result from the most volatile and explosive events in the Universe such as supermassive black holes spewing out cosmic matter, explosions of superluminous supernovae or the rotation of magnetars, a type of neutron star beats anything it can get its hands on with intense magnetic fields. But according to Harvard scientists and their forthcoming publication in the next issue ofAstrophysical Journal Lettersthis is all just speculation based on the assumption that such strong signals would come from the strongest events ever detected.
So what ? For Avi Loeb, if no one is able to agree on a natural source so far, then maybe we should look at some sources, let’s say less natural. In a recently published document, the researchers postulate that these radio signals are in fact the remains of beams set up by extraterrestrial civilizations: lightsails. If you are not familiar with this technology, it is still in its infancy – at least on Earth – but it could potentially revolutionize space exploration by allowing, for example, to reach Mars in just three days.
Known as a « photonic propulsion » system, the lightsails are powered by the dynamics of photons (particles of light) that could be harnessed by the sun’s rays or generated by giant Earth-based lasers. Put simply, this means we would need virtually zero fuel and interstellar travel could last as long as the physical parts hold. Loeb and his team do not exclude this idea, suggesting the possibility that a gigantic radio transmitter is installed billions of light years away. To emit such signals, the transmitter would have to cover an area like twice the Earth to collect enough sunlight.
Such a device accords with the laws of physics for the researchers who also point out that the purpose of such a colossal construction would be twofold: it could not only send signals across large areas of the Universe to other civilizations ( like ours?), but could also propel probes or spacecraft very long distances through interstellar space. Of course, all of this is still speculative and Loeb does not claim to have an answer to each of the questions proposed.