What are repeating FRBs or fast radio bursts? A quantum physicist decodes this term & explains the phenomenon.
If you were the point of contact for an alien civilisation, what’s the first thing you would say? I would probably tell the aliens about coffee, and then have them try some. That would surely, and perhaps literally, warm them up to us.
I ask this because I’m a complete sci-fi romantic, and some recent astronomical news has left me daydreaming like Cinderella before she met Prince Charming. Full disclosure: no, we have not found evidence of an alien civilisation.
In fact, my starting off the way I did was probably misleading. However, the detection of repeating fast radio bursts – only the second of its kind to ever be discovered – is significant. Let me tell you why.
What Are Fast Radio Bursts?
First, fast radio bursts (FRBs) are super high energy radio pulses that come from the skies (read: a few billion light years away). While super high energy at their source – a few milliseconds of energy emission can match how much energy our sun emits in a day – by the time they reach the Earth, they emit way less energy.
Think about going to the moon and then trying to receive a signal from Earth on your phone: perhaps a parent is trying to call because you left your jacket behind. Got the visual? The strength of these FRBs when they reach us, is a thousand times less than that.
Substantial Population of Repeating FRBs
Since 2007, these FRBs have been detected over sixty times. Most were individual signals from different sources; only once was a repeating set of signals ever detected. Until now. In July and August 2018, the Canadian Hydrogen Intensity Mapping Experiment (CHIME) FRB project detected six repeating FRBs that appeared to originate from a single source 1.5 billion light years away, along with seven other individual signals.
For a bit of perspective, I’d like to point out that our Milky Way is only about a hundred thousand light years in diameter.
That repeating FRBs were detected at all, gives rise to a number of suggestions. One, repeating FRBs are not an anomaly. The first detection wasn’t a standalone, and according to the CHIME/FRB Nature paper, this second detection “suggests that there exists—and that CHIME/FRB and other wide-field, sensitive radio telescopes will find—a substantial population of repeating FRBs.”
Much More To Be Known About Repeating FRBs
Two, repeating FRBs are inexplicable from the viewpoint of our limited knowledge, and may point to all sorts of unknown powerful astronomical events far, far away! That’s always exciting.
Three, we actually don’t know much about FRBs and their origin, and trying to zoom in on a single source that gives out repeating FRBs, might provide us with the data to know more.
Four, since the sources are unknown, FRBs may have an alien origin. Indeed, Prof Avi Loeb of the Harvard-Smithsonian Centre for Astrophysics, says, “Fast radio bursts are exceedingly bright given their short duration and origin at great distances, and we haven’t identified a possible natural source with any confidence. An artificial origin is worth contemplating and checking”.
Let me point out that “aliens” isn’t really the first answer that most have when new, inexplicable, exciting things are discovered. Very few scientists are embracing this idea for repeating FRBs because it is incredibly, and I can’t stress this enough, incredibly premature.
So, instead of running through the streets proclaiming that we are not alone, daydream with me. I ask you again: what’s the first thing you, as a point of contact, would say to aliens?