How many supernova explode every year? • Hacker News Board

Re: How many supernova explode every year?

#11

Post by Cyphase » Tue, Apr 15, 2025, 9:28 AM UTC

darthrupert wrote: post #2

The whole things seems like such a massive living system that I cannot help guessing that what we think of as universe is just a somewhat large single creature.

This reminds me of this quote from Jill Tarter of SETI, specifically the last sentence:

“Might it be the discovery of a distant civilization and our common cosmic origins that finally drives home the message of the bond among all humans? Whether we’re born in San Francisco or Sudan or close to the heart of the Milky Way Galaxy, we are the products of a billion-year lineage of wandering stardust. We, all of us, are what happens when a primordial mixture of hydrogen and helium evolves for so long that it begins to ask where it came from.”

source: https://www.ted.com/talks/jill_tarter_join_the_seti_search (@ 3:02)

Re: How many supernova explode every year?

#12

Post by tialaramex » Tue, Apr 15, 2025, 9:31 AM UTC

ndsipa_pomu wrote: post #6

darthrupert wrote: post #2

The whole things seems like such a massive living system that I cannot help guessing that what we think of as universe is just a somewhat large single creature.

It's an appealing idea, but surely there'd be insurmountable problems with the distance/time involved for any part to communicate to another part? It'd be like trying to run a computer with a clock that takes millions (billions?) of years to make a single tick. I just don't see that it's at all feasible and that's without even trying to guess as to how different parts can change behaviour depending on its environment…

> a clock that takes millions (billions?) of years to make a single tick

Much worse than that, the universe is enormous and it is expanding faster than the maximum possible velocity, as a result such a clock could never complete a single tick.

Re: How many supernova explode every year?

#13

Post by ndsipa_pomu » Tue, Apr 15, 2025, 9:34 AM UTC

jampekka wrote: post #8

I couldn't spot the supernova and there's no answer to where it is. :'(

It's in NGX 1566

Re: How many supernova explode every year?

#14

Post by dkersten » Tue, Apr 15, 2025, 9:38 AM UTC

ndsipa_pomu wrote: post #6

darthrupert wrote: post #2

The whole things seems like such a massive living system that I cannot help guessing that what we think of as universe is just a somewhat large single creature.

It's an appealing idea, but surely there'd be insurmountable problems with the distance/time involved for any part to communicate to another part? It'd be like trying to run a computer with a clock that takes millions (billions?) of years to make a single tick. I just don't see that it's at all feasible and that's without even trying to guess as to how different parts can change behaviour depending on its environment…

What’s wrong with it taking a billion of our years to tick? Just because we, smaller than microscopic beings compared to the size of the larger structures we observe, find it to be a vastly long time, doesn’t mean that it’s a long time for something the size of the observable universe.

For a single bacteria cell, our timeframes must seem immense too.

I’m not saying it’s particularly likely, but it’s a trap to think that just because you can’t fathom the scales that makes it impossible. The universe is huge and very very old. It can afford to wait what is a long time to us for something to happen.

I do think you’re likely right in practice though, and that it is too long for the universe to be an organism. But who knows. We already know that mathematically speaking the heat death of the universe looks identical to a very zoomed in big bang, maybe we just need to zoom out a few billion orders of magnitude to see the big picture, where the vast distances and time scales we see appear as little more than micrometers and microseconds apart…

Re: How many supernova explode every year?

#15

Post by subscribed » Tue, Apr 15, 2025, 9:42 AM UTC

drbig wrote: post #3

The universe is vast and full of nothing... Which in case of explodey stars is a very good thing indeed!

It's fun to think that at some point it will be actually vast and completely dark

Re: How many supernova explode every year?

#16

Post by deadbabe » Tue, Apr 15, 2025, 9:42 AM UTC

Can the thread title be rewritten to be less obnoxious? “How many supernova explode every year?” is fine. This isn’t Reddit. Thread titles should not imply some kind of personality or use cliche meme speak. The all caps is definitely an abomination.

Re: How many supernova explode every year?

#17

Post by fooker » Tue, Apr 15, 2025, 9:51 AM UTC

deadbabe wrote: post #16

Can the thread title be rewritten to be less obnoxious? “How many supernova explode every year?” is fine. This isn’t Reddit. Thread titles should not imply some kind of personality or use cliche meme speak. The all caps is definitely an abomination.

Please read the article along with bikeshedding titles. It's a good one.

Re: How many supernova explode every year?

#18

Post by herendin2 » Tue, Apr 15, 2025, 9:53 AM UTC

If I got the math right, then about 1 in every 32,000 stars in the universe goes supernova each year. That's scary. But I think I'm getting the math very wrong.

edit: I guess my error might be related to confusing a probability factor with the number of incidents in a period.

edit: The right answer is probably up to 1 in every 10bn stars go supernovae in the universe each year (or 1 in 10bn die and a fraction are supernovae). Thanks: yzydserd and zild3d

Re: How many supernova explode every year?

#19

Post by Timwi » Tue, Apr 15, 2025, 9:56 AM UTC

deadbabe wrote: post #16

Can the thread title be rewritten to be less obnoxious? “How many supernova explode every year?” is fine. This isn’t Reddit. Thread titles should not imply some kind of personality or use cliche meme speak. The all caps is definitely an abomination.

Agree. For the record (in case it gets changed), the title at time of writing is “Wait. HOW MANY supernova explode every year?”.

Re: How many supernova explode every year?

#20

Post by ndsipa_pomu » Tue, Apr 15, 2025, 9:58 AM UTC

dkersten wrote: post #14

ndsipa_pomu wrote: post #6

Earlier quoted context omitted.

It's an appealing idea, but surely there'd be insurmountable problems with the distance/time involved for any part to communicate to another part? It'd be like trying to run a computer with a clock that takes millions (billions?) of years to make a single tick. I just don't see that it's at all feasible and that's without even trying to guess as to how different parts can change behaviour depending on its environment…

What’s wrong with it taking a billion of our years to tick? Just because we, smaller than microscopic beings compared to the size of the larger structures we observe, find it to be a vastly long time, doesn’t mean that it’s a long time for something the size of the observable universe. For a single bacteria cell, our timeframes must seem immense too. I’m not saying it’s particularly likely, but it’s a trap to think t…

The problem with zooming out is that the speed of light sets a specific size/time scale so the more zoomed out you get, the more disconnected the big picture is. The observable universe is a mere 93 billion light-years across, so there's a limit on how far it makes sense to talk about zooming out. Also, with the universe expanding, the observable size will reduce over a long time period.

The scales involved are vastly different than the minor difference in scales between bacteria and us - we don't have to worry about the speed of light for anything that we currently consider alive.