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Comment by netcraft | Hacker News Reader

the Gravitational Observatories are so impressive to me - I can remember reading about them being theoretical well before LIGO ever started construction, and the fact that theyre here and working just like we expected is so amazing. I can't wait until we have LISA in space!

But its so strange when we shut it off to do upgrades and stuff - like I totally understand why we have to do it, but its like we finally turned on a microphone and could hear things that were always happening but we could never observe before, and then we turn it off for a little while - the thought that there are events that are going on right now that we will never be able to detect because we arent listening gives me major FOMO.

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LIGO collaboration member here: we focus on maximizing the cumulative number of detections over time, and it turns out that by turning the detector off for a year to upgrade it, we can increase the sensitivity so much that a year after that we will have more total detections than if we had left it running continuous for two years. So you also have to think about all the distant/faint signals we would never be able to detect because we kept listening at too low a sensitivity...

(We do make sure that we have a dramatically less sensitive sister detector in Germany, called GEO, listening whenever we're not so that we'll see something really close and loud, like a galactic supernova, even when LIGO is offline.)

I sincerely love that your reply to FOMO was to point out how his FOMO should be even worse. This is exactly how my brain works when I'm optimizing something: I have to balance one obsession with all the other things I need to obsess about.

Thanks for the info! I expected it was something like this, that you expect the increased sensitivity is worth it. I just wish we had more observatories running in different sensitivities - we've just got to get the cost down, thats all :)

I didn't know about GEO, thanks for that!

That makes me think of the "Wait calculation" in https://en.wikipedia.org/wiki/Interstellar_travel#Wait_calcu...

Also the experimentalists get very antsy when they/(we) can't touch the instrument. :-)

> the thought that there are events that are going on right now that we will never be able to detect because we arent listening gives me major FOMO.

I can relate to the sentiment but keep in mind that human timescales are downright puny compared to cosmological timescales. And there's lots of stuff going on all the time (lots is an understatement) so I would say you won't lose much turning off the detector for a year.

I totally understand this from a rational standpoint, but if you take that to its logical conclusion, you expect that nothing will happen in that year that is very interesting or rare, so why look at all?

Sure, our timescales are nothing, making what we have even more valuable, no? We've missed out on a whole lot of observations - we have a lot of catching up to do!

Why would you have FOMO? Why is any particular gravitational wave important enough that you'd worry about missing it? I'm not trying to hassle you here, I'm genuinely perplexed by this attitude.

I used to work in a library and we all had a similar feeling about books. They were all valuable and to be preserved! Objectively, that's not practical. But that base irrational feeling is still useful and important.

Technically we've missed at least four billion years of gravitational wave events, so a week of shutdown for an upgrade isn't going to make a huge difference to that.

I miss those days four billion years ago, before modern worries and before days.

only for Earthlings. I'm sure (hopefully) someone on a rock around a different star might have had those worries in their day too.

Yes, that's where the practicality comes in. But I'm sure there are people who have FOMO over all that data collection we missed over the last 14 billion years. And that's good! Maybe somebody will come up with something clever that is better than nothing. E.g., all the CMB work: https://en.wikipedia.org/wiki/Cosmic_microwave_background

My crude searching tells me there are ~3 supernovas in our galaxy every century. Miss one now and the next might wait for the next generation of astrophysicist.

Close by, interesting astronomical events are rare.

The last decent naked eye supernova was the crab nebula in 1054.

It would be a real shame to miss the next one in this galaxy.

Other "rare" (non-gravitational wave) events I can think of are: the Shoemaker Levy comet hitting Jupiter, the Carrington Event in 1859, Betelgeuse dramatically dimming (last year).

Last 'decent' naked eye supernova was surely Kepler's Supernova of 1604. And the recent fading of Betelgeuse wasn't all that unusual for a fairly typical red supergiant pulsating star.

I replied to a sister comment similarly, but the one resource that we are severely limited by is time. There were events that were far more common in the early universe that we may never see now. Rare things could happen at any time.

The reality is that we can't observe 100% of the time for resource constraints and that the cost/benefit of upgrading is totally worth it in the long run - rationally speaking its the right move. I will just always wonder what we are missing out on that we might never have the opportunity to observe again - or maybe not in our lifetimes.

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