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How many supernova explode every year?

badastronomy.beehiiv.com

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Re: How many supernova explode every year?

#111

Post by Wobbles42 »

yzydserd wrote: post #44
roenxi wrote: post #4

We're dealing with the sum total of everything, if the true nature of things is that there are a finite number of supernovas I'd be surprised. The real shock is how small the number of supernovas is and how young everything seems to be in the known universe (the age of the observed universe is estimated at maybe double digit billion years). These are tiny numbers given that we're quite possibly dealing with infinity…

its 1 supernova per century per galaxy. there are many galaxies: more than 10 stars go supernova every second across the universe. tens of thousands have gone supernova since the article was posted to HN. tiny percentages in a large sample are huge numbers, you might even say 'astronomical'.

There is a really good intuitive analogy hiding here for the scale of the universe:

Our galaxy is to the observable universe as a tenth of a second is to your entire lifetime.

Re: How many supernova explode every year?

#112

Post by danso »

SwtCyber wrote: post #28
tialaramex wrote: post #9

That's one of my favourite hints in Outer Wilds. You will see a Supernova. Not with a fancy telescope, it's visible to the naked eye, and if you watch the sky you'll see another soon enough. You can see this right at the start, and unlike the random direction of the probe launch you don't need any game lore to, if you're smart enough, put two and two together.

Honestly one of those rare games that makes you feel like a real explorer, not just someone following a path the devs laid out.

Truly one of the most purest of video games in terms of player freedom, I’m still sad that I didn’t think to record my own playthrough as everyone’s path of discovery is more or less unique.

The freeform gameplay and incredible ending makes OW easily my pick for best game of all time, even though it’s also my least replayed favorite game.

Re: How many supernova explode every year?

#113

Post by Wobbles42 »

foxglacier wrote: post #10
roenxi wrote: post #4

We're dealing with the sum total of everything, if the true nature of things is that there are a finite number of supernovas I'd be surprised. The real shock is how small the number of supernovas is and how young everything seems to be in the known universe (the age of the observed universe is estimated at maybe double digit billion years). These are tiny numbers given that we're quite possibly dealing with infinity…

You can't compare a number of years or events with infinity. Saying it's tiny or huge makes no sense whatsoever. What amazes me is how young the universe is compared to life. The universe is only about 4 times as old as life on Earth.

Or to flip that around, life has existed on Earth for about 25% of the lifetime of the universe.

The fact that we are part of that life introduces some nasty sampling biases, but if we find even one more planet that shows a similar ratio, the implications will be that life is ubiquitous.

Re: How many supernova explode every year?

#114

Post by [deleted] »

wolfram74 wrote: post #82
ben_w wrote: post #74

Hmm… So that's cool, but now I'm thinking: the distant galaxies are redshifted and time-dilated in equal proportion, and also more densly packed because the universe was smaller in the past, so I expect the actual rate of supernovas to be significantly smaller than simply multiplying 1/century/galaxy by 1e11 galaxies. Edit: also I don't know if rate of supernovas changes over history thanks to different steller envir…

I would imagine the supernova rate to be higher in the early universe, as we've already passed peak stellar formation rates and the heavier (and shorter lived) stars were more likely to be formed earlier when the average density of the universe was higher.

[deleted]

Re: How many supernova explode every year?

#116

Post by jxf »

SwtCyber wrote: post #31
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.

There's something kinda poetic (and maybe even logical) about the idea that what we perceive as scattered galaxies and physics is actually just the internal processes of something far bigger than we can comprehend.

Poetic, or maybe Lovecraftian. A lot of "cosmic horror" has the trope of vastnesses too big to comprehend, where even trying to think about it (or in some cases merely learning of the possibility) causes you to go mad.

Re: How many supernova explode every year?

#117

Post by [deleted] »

ben_w wrote: post #74

Hmm… So that's cool, but now I'm thinking: the distant galaxies are redshifted and time-dilated in equal proportion, and also more densly packed because the universe was smaller in the past, so I expect the actual rate of supernovas to be significantly smaller than simply multiplying 1/century/galaxy by 1e11 galaxies. Edit: also I don't know if rate of supernovas changes over history thanks to different steller envir…

[deleted]

Re: How many supernova explode every year?

#118

Post by Wobbles42 »

dylan604 wrote: post #95
Wobbles42 wrote: post #87

Earlier quoted context omitted.

That is unfortunate. With only two prime factors, one of which being 13, base 26 is even worse than base 10, and it doesn't even have anatomical coincidence to recommend it. Much better to use base 36 -- we have a ready made character set for it by simply adding the digits to the 26 alphabetic characters. This gives us many more integer prime factors. Not as good as base 60, but better than base 26 and finger numbers…

Why the assumption that base36 would use the western alphabet. If they use Cyrillic, they'd have 33 chars. If they use Japanese, they'd have 46 chars. Using Hindi, they'd have 50 chars. https://wordfinderx.com/blog/languages-ranked-by-letters-in-... I have no clue as to the accuracy of this website, but accuracy isn't something we strive for when making ridiculous comments on the interwebs, is it?

Well, the assumption was based on the fact that they chose base 26, and that the "26" came from the use of a 26 character alphabet. The 10 Arabic numerals are then a convenient character set to expand to 36, which is a much nicer number base than 26.

Japanese could be combined with the Hindi character set to yield base 96, which is fairly convenient. Cyrillic would be harder -- perhaps the best options there would be to drop a character to yield base 32, or perhaps 3 characters to yield base 30.

I'd argue that base 60 is probably the optimal number base for nearly any use (with base 16 or 64 as close second and third for working with binary data). Hindi's 50 characters combined with our 10 Arabic numerals could indeed be a great way to get there.

Re: How many supernova explode every year?

#119

Post by bee_rider »

IggleSniggle wrote: post #73
IggleSniggle wrote: post #65

Earlier quoted context omitted.

It's in the article. SN2067aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa vs SN2067aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa. Apparently astronomers find base26 very straightforward and reasonable!

Also, as a cousin comment alludes to, for there to be one of the above supernovae, there will also be a supernova named SN2067iamsoverystupidoopssorry and a SN2067thisnamingschemawasabadidea

I guess we’re already hitting four letter words, was there a supernova “butt” last year?

Re: How many supernova explode every year?

#120

Post by criddell »

rookderby wrote: post #81

First off, dont look at the outer wilds discussion on here, just play the game. Second - they didnt say how many letters we need to encode all of the observable supernova in a given year! So 100 billion galaxies, 1 per year per galaxy, we have around 1 billion to encode. Sorry two edits this moring, first one was right. due to math without coffee. 1e9/26^6 is about 3, 1e9/26^7 is less than one. So we might see 'SN205…

I bought Outer Wilds based on recommendations like yours and I found it kind of boring. The world is mostly empty and the repetitiveness wore me down. I didn't finish it.

It's a great looking game though and the first hour or two I had a blast.

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