There are many things in the universe that we still have to understand. She only throws up riddles, and we, tiny specks crawling along the surface of a small blue dot, do our best to solve them.
Recently there was news of one of the most exciting mysteries. For the first time, a fast radio burst (FRB) was discovered, which has a 16-day cycle with four days of intermittent bursts and 12 days of silence.
We still don't know what is causing these extremely powerful, millisecond bursts of radio waves up to billions of light years away. Most were not repetitive, most were highly unpredictable, and only five of over 100 were traced back to the original galaxy.
It was extremely difficult to find a cosmic phenomenon that matches the signal profile. Furious, highly magnetized neutron stars called magnetars are fairly close, but there is some doubt as to whether they can emit Nova-scale energies found in fast radio bursts.
But the lack of a clear explanation does not yet mean that we should automatically turn to alien civilizations. When unusual cosmic phenomena appear, unbridled fantasy comes to this assumption too quickly.
“Calling aliens has become too systematic, too simple and too sensational a way to get public attention … [It] reminds me of how we used to call on the gods,” planetary scientist and astrobiologist Charlie Lineweiver of the Australian National University (ANU) told ScienceAlert.
Alien communication.
In 2017, some physicists suggested that fast radio signals could be generated by leaking radiation from the propulsion systems of an alien spacecraft. Others have put forward the idea that this could be a one-way alien connection.
“As far as I understand, these explanations are not excluded by the available evidence,” said physicist Paul Ginsparg of Cornell University and founder of arXiv.
'But also the fact that they don't need them, in the sense that there remain the same or more plausible explanations that do not use extraterrestrial intelligence.'
One big problem for an alien idea is the variety of locations and distances. Of the signals that have been localized, some are billions of light years away; others from hundreds of millions.
As noted by astronomer Seth Shostak of the SETI Institute, this reason alone is sufficient to refute the hypothesis that FRB is an extraterrestrial connection.
“How could aliens have mastered such unimaginable spaces of the universe to broadcast the same signal?” he wrote a blog post last year.
“After the Big Bang, there was hardly enough time to coordinate such incredible teamwork, even if you can think of a reason for it!”
For signals to be artificial, at least 100 different alien species would have to be incredibly technologically advanced to generate such a powerful signal that it can travel through space and still be detected by us.
For context, here on Earth, we only developed technology that could emit radio waves into space just about 125 years ago. This means that any radio transmission from Earth would travel no more than 125 light years. By the time the signal travels this far, it will become too weak to be detected.
This does not mean that a more advanced civilization cannot send a powerful signal … but there is another problem. All of these hypothetical alien civilizations would have to develop their technologies at the right time in order for all their signals to reach Earth in the same few years.
Are we alone?
To date, we do not have reliable evidence that there are other intelligent, advanced civilizations. The lack of evidence for other civilizations seems paradoxical in the context of the Drake equation, which suggests that there must be many such civilizations around.
But should it? Of all the many species on Earth, only humans have advanced intelligence.
“My understanding of biological evolution on Earth is that human intelligence is not a converging line of evolution,” said Linewiver.
“The point of my thinking is that the best data we have (evolutionary data here on Earth) strongly suggests that our closest relatives in the universe are here on Earth.”
Thus, there are logistical grounds to believe that fast radio bursts are of natural origin. As the interstellar object 'Oumuamua' was ultimately discovered, another target for the presence of aliens – there is actually evidence in the data that this is a natural phenomenon.
'I think the best argument against the extraterrestrial hypothesis is that we see signals with all sorts of strange properties (some are wide, some are narrow, some are polarized, others are not, some have multiple pulses, some have one pulse),' – an astronomer who wished remain anonymous for fear of being targeted by conspiracy theorists.
'If I were to design a spacecraft propulsion system (which would be a hell of a lot of fun), I'm not sure if some of these properties (like changing polarization with momentum) would make the spacecraft's engine better.
On the other hand, we see a similar variety of properties in pulsars, which, by all accounts, is a natural phenomenon. '
This line of thinking is also supported by astronomer Andy Howell of the Las Cambres Observatory and the University of California, Santa Barbara.
The value of creative ideas.
All this does not mean that there is no point in considering explanations in the form of an intelligent civilization. It is important for scientists to remain impartial, to be receptive to opportunities, even if they are small.
Consider cases – even if they represent only a small percentage – of hypotheses initially ridiculed by the scientific community, but later widely accepted. The existence of tectonic plates comes to mind.
Bold ideas can also help keep the public interested in science; not only the discoveries themselves, but the work that scientists undertake to present a hypothesis, provide evidence for it, and create a theory.
And there are practical possibilities too.
“These discussions give interested people information about what amazing observations have been made, what scientists think of them, and the possibilities that exist,” Jinsparg said.
'Speculation can sometimes be tested with next-generation tools that can either confirm or disprove a hypothesis, or see something completely unexpected. And that also makes science fun. '
The difficulty lies in understanding the difference between thinking about new ideas as an exercise for reflection and evidence based on data and previous experience, observations and conclusions.
Or, as Jinsparg said, “In a discussion on string theory, a senior physicist once argued to me that you cannot 'prove' that there is no Santa Claus, but that we have alternative ways of explaining the observed phenomena with fewer unnecessary assumptions. '
So, for now, we discard the alien origin of fast radio bursts, until aliens tell us otherwise.
Sources: Photo: (NRAO Outreach / Vimeo)
