Astronomers detect regular rhythm of radio waves, with origins unknown

Post by pgt » Sun, Jun 28, 2020, 2:34 PM UTC

jrichardshaw wrote: post #104

pso wrote: post #67

Earlier quoted context omitted.

Pure speculation, isn't the most interesting time period in the signal the transition from signal to no-signal (and back again)? How high is the resolution of the sensors? Is it possible that some frequencies are blocked fractionally earlier than others? At a fine enough temporal resolution, there might be more clues regarding the source.

Good question. For many FRBs there is access to the original antenna time streams (which are essentially voltages samples at 800 MHz), so superficially that might give you 1.25ns resolution. However, the intrinsic width of the pulses seem to be more like ~1ms. That tells you something about the emission source, giving you a rough upper bound on it's size of c * 1ms ~ 300km. However, lots of interesting plasma physics…

Post by Zenbit_UX » Sun, Jun 28, 2020, 2:46 PM UTC

teraflop wrote: post #33

savrajsingh wrote: post #9

They didn’t mention a simpler solution: random emitter orbits behind something / Is occluded for the silent period?

I'm having a hard time imagining what kind of geometry would cause an orbiting object to be occluded for more than 50% of its orbital period.

Post by aaaxyz » Sun, Jun 28, 2020, 4:25 PM UTC

pgt wrote: post #151

jrichardshaw wrote: post #104

Earlier quoted context omitted.

Good question. For many FRBs there is access to the original antenna time streams (which are essentially voltages samples at 800 MHz), so superficially that might give you 1.25ns resolution. However, the intrinsic width of the pulses seem to be more like ~1ms. That tells you something about the emission source, giving you a rough upper bound on it's size of c * 1ms ~ 300km. However, lots of interesting plasma physics…

You just made me realize that it would be cheaper for an advanced civilization to send a message light years away by altering the medium through which the signal passes than to control the source directly, e.g. a neutron star.

Post by Joeri » Sun, Jun 28, 2020, 5:08 PM UTC

antepodius wrote: post #139

gubby wrote: post #134

Earlier quoted context omitted.

An instantiation of me from a backup, however accurate, would be no use to my sense of having survived as I would have ceased to exist and not even be aware of the copy.

That's fine! People with your philosophy of self will just cease to exist, as they presumably will refuse to optimize for likelihood of being simulated, and those with a more permissive notion of self-identity will be the ones willing to adapt to the hellish computational circumstances. (Of course, you could say that everyone's ceasing to exist, here, because your rules of what counts as a person and what's their cop…

Post by jrichardshaw » Sun, Jun 28, 2020, 5:19 PM UTC

johnwangdoe wrote: post #117

jrichardshaw wrote: post #54

One of paper authors here. I'll try and answer some of the questions in the comments. It seems like so long ago the paper actually went public onto the arXiv, but I guess the press embargo just ended.

WHat do you think about Contant the movie in relations to your job?