[aquova]

My first thought was that this sounds like a pulsar, and I was surprised to not see that among the list of possible phenomenon. After looking it up, I still wasn't quite sure why these couldn't be pulsars. Is it because the period is much higher than typical pulsars?

[teraflop]

The article suggests it could be a spinning neutron star, which is what a pulsar is. But a pulsar produces an extremely regular sequence of pulses. (Well, actually it emits a continuous beam of radio waves, but its rotation causes the beam to point towards any given observer at regular intervals.)

This article describes a source that seems to start and stop at regular intervals of several days (much longer than any known pulsar's rotational period) but within the active intervals, the bursts appear to be random. That suggests a more complex mechanism is at work.

[rootbear]

I just throw some gasoline on the "It must be Aliens!" theory (to which I do not subscribe!) and point out that heavily compressed data looks random...

[menybuvico]

As does encrypted data.

[elwell]

Compression is just a bad encryption algorithm. Encryption is just a bad compression algorithm.

[beamatronic]

That’s why somebody needs to send out a sequence of prime numbers

[lumost]

What protocol do you use to represent the sequence? Bytes, Morse, Amplitude modulation, frequency modulation? All of these combinations may appear random to one without the right codec.

[0-_-0]

1 is 1 blip, 2 is 2 blips, etc. just like in the movie

https://en.wikipedia.org/wiki/Unary_numeral_system

[beamatronic]

I wonder if this could be accomplished with a train of satellites. All in the same orbit. Just spaced out like this:

xx xxx xxxxx xxxxxxx

So they just go around and around, including the light, from the point of view of a far away perspective

[namarie]

It would take 500 million years to get there, if the signal was strong enough in the first place.

[anoniuyiu33412]

Maybe is encrypted because we are not the intended receiver.

[jrichardshaw]

Pulsars aren't 100% ruled out, but I think they're considered reasonably unlikely. The problem is mostly the apparent brightness. If you place almost any known pulsar (which are all in our galaxy) at the in the host galaxy of a localised FRB which(only a fraction of FRB's do we have measured distances for, but they're all quite far away), if would be far too dim.

The only exception to this is the Crab pulsar, which is observed to occasionally have "giant pulses" which are 1000s of times brighter than a typical pulse. If you put the a somewhat brighter version of the Crab pulsar in an FRB host galaxy at the low end of the known distances, you might just about be able to see it.

[nabla9]

One explanation might be a pulsar circling something.