Betelgeuse going supernovae

[nutball]

nutball, Geminga exploded hundreds of thousands of years ago. We don't really know if it had a zero impact on life, but more to my point, there was no intelligent civilization around to watch it.

Hmmm. Well my response was basically toward Kruno, who's afeared that a nearby supernova might destroy the Earth. Which Geminga didn't. Nor did it wipe out the members of the genus Homo who existed at the time (Neanderthal man, for example, who were supposedly reasonably intelligent and may well have enjoyed the light-show).

So you're right, we don't know with absolute certainty what impact a Betelgeuse supernova might have on current human civilization. However in a vain attempt to stem the tide of Internet silliness, Geminga is a good reference point that suggests strongly that a nearby supernova

- won't destroy the Earth
- won't destroy life on Earth
- won't destroy intelligent life on Earth

 

[chavvdarrr]

yet another possibility for Apocalypse:
http://arxiv.org/ftp/arxiv/papers/1004/1004.3917.pdf

 

[NRP]

All this talk reminds me of the time back in school when a science teacher got angry at me for mispronouncing Uranus.

 

[pcchen]

All this talk reminds me of the time back in school when a science teacher got angry at me for mispronouncing Uranus.

Don't worry, it's going to be renamed to Urectum in 2620.

 

[K.I.L.E.R]

AFAIK, there aren't any stars massive enough to supernova that are close enough to harm us.

I'd be more concerned about magnetar starquakes if I was inclined to worry over random things I have no control over... There was one a couple years back that originated from an object somewhere around half the width of the milky way away (I forget which), on the other side of the galactic core. That discharge was powerful enough even at this enormous distance to partially ionize the earth's upper atmosphere and scrambled the circuits of some satellites I believe.

If that magnetar had been only as far away as Betelgeuze when it went off this planet would have been completely sterilized of all life. Probably had its atmosphere blown off, oceans boiled away into space, possibly even rock melted etc by massive X/gamma-ray bombardment...

Magnetars are freakishly dangerous, powerful and scary things. Fortunately for us - again - there doesn't seem to be any close enough around us to really pose any significant threat.

Magnetars could be one reason there doesn't seem to be a space colony in every solar system in this galaxy. It's quite possible each flare-up wipes out life on one or any number of worlds out there in the cosmos...

Did anyone pick up that Magnetar prior to it going spastic? I can't believe how close we came to death that day.

 

[Grall]

Did anyone pick up that Magnetar prior to it going spastic?

I believe the star remnant in question was known beforehand - these things are X-ray sources, so they show up on telescopes designed to pick up that part of the spectrum. However I'm not sure if scientists knew it was a magnetar or not.

I can't believe how close we came to death that day.

Heh, apart from the fact we weren't close to death at all, that is true yes.

Seriously, there's only like a little over two dozen of these things - that we know about - in the entire GALAXY. They're not particulary common, probably because their shelf-life is quite short. Their magnetic field decays in only about 10.000 years, and since they are a type of neutron star, they require a supermassive star going supernova first to even come into being, and such stars aren't particulary abundant in our corner of the galaxy. That's why we even exist in the first place, no novas wiped us out while we were still primordial ooze... We live in a dull, safe neighborhood, you might say.

Betelgeuze going nova would be spectacular, but my favorite volatile celestial object is the blue variable hypergiant Eta Carinae. It's a binary (or maybe more) star system, where the main star masses an estimated 80-100 solar masses (!!!) and shines millions of times as bright as our sun. It's also extremely temperamental, some time in the 1880s if I remember correctly, it had a little 'episode' and ejected something like a quarter of a solar mass in a violent explosion that now exist as a hourglass-shaped nebula around it that is quite beautiful actually. Look up images of it on the web...

This star's a crazy madman strapped with explosives around his waist, and with a twitchy trigger finger, and it won't be around for all that much longer (few hundred millennia at most); apparantly spectral scans of its light shows substantial amounts of iron, so it'll go through a core-collapse supernova in relatively short order. Fortunately for us, Eta Carinae's also relatively far away, much farther than Betelgeuze (I think around 2000-2500 LY or somesuch).

 

[K.I.L.E.R]

I find it quite strange that we always come out fine in such a chaotic universe. Maybe Intelligent Design is real?

 

[Grall]

Why would it be?

If intelligent design was real, why are there even such objects around? Heck, why would there even be an entire universe out there? It serves no function at all if humans were to be the most important invention since ever. In fact it's likely to be our undoing, if we don't manage that ourselves first, as undoubtedly some day some ten-kilometer-plus impactor's going to smash into us and make a mighty big hole somewhere on our planet, and that'll wreck the ecosystem and that'll wipe us all out. Assuming we don't die in the shockwaves, tsunamis and fires, of course.

Truth is far more boring, I'm afraid. It's nothing more than we happen to be because the chances for our coming into being existed, here.

 

[Argoon]

That's not dangerous though. A tiny black hole should explode immediately if Hawking is right, and the energy released should be no more than E=mc^2 for the black hole (which is tiny). Even if it doesn't explode (i.e. there is no Hawking radiation), the chance of it bumping into some mass for it to "grow up" is extremely small as the cross section is, well, extremely small.

I could be wrong but i seam to remember reading on hawking book that is theory fails on very very small black holes.

 

[pcchen]

I could be wrong but i seam to remember reading on hawking book that is theory fails on very very small black holes.

Yes, no one knows even whether extremely small black holes are possible (the radius is smaller than Planck constant). If they are impossible than they probably aren't dangerous at all. If they are possible, the cross-section-is-too-small argument should still apply, so they are still not very dangerous.

The only dangerous is that, for some reason, micro-blackholes are able to produce much more energy than its own mass (i.e. larger than E=mc^2). That's extremely unlikely, and if true, should be a new energy source and not necessarily a bad thing

 

[K.I.L.E.R]

How do you contain such a small black hole if it has more energy than its own mass?

 

[pcchen]

How do you contain such a small black hole if it has more energy than its own mass?

Well, you don't need to "contain" it. Suppose that it's possible to create a small black hole which is able to generate much more energy than its own mass (thus the energy required to create it), you can create it in the outer space, let it explode by itself, and put a few solar panels around it to collect the energy. The point here is, if it's possible to create energy out of nothing, you have an unlimited supply of free energy.

Of course, it's very unlikely for the world to work this way (to get free energy).

 

[rpg.314]

The only dangerous is that, for some reason, micro-blackholes are able to produce much more energy than its own mass (i.e. larger than E=mc^2). That's extremely unlikely, and if true, should be a new energy source and not necessarily a bad thing

That's not extremely unlikely. It is absolutely impossible.

 

[London Geezer]

Just wanted to point out that supernovae is plural... So Beetlejuice (... Beetlejuice! Beetlejuice!! ) is going supernova.

 

[Grall]

if it's possible to create energy out of nothing, you have an unlimited supply of free energy.

Isaac Asimov once wrote a short story about how aliens from another dimension taught humans how to create free energy.

I don't want to spoil the ending of the story, but as it turned out it wasn't so free after all.

 

[pcchen]

That's not extremely unlikely. It is absolutely impossible.

Well, although I have a lot of faith in the law of conservation of energy, I still won't say "impossible" when dealing with situations where current physics laws don't cover.

 

[WhiningKhan]

Isaac Asimov once wrote a short story about how aliens from another dimension taught humans how to create free energy.

I don't want to spoil the ending of the story, but as it turned out it wasn't so free after all.

It's not a short story, it's a novel (The Gods Themselves). Just as a pointer for those few among us who have somehow failed to read it yet.

 

[Grall]

Hm, it was a short story in the book I read it, decades ago by now, and it wasn't in the original English. Probably a condensed version then. As I recall, it was very, very interesting.

 

[chavvdarrr]

afaik , it started as small story, and years later he made it to a novel. Not sure tho it was long ago when i read his biography.

BTW, I had forgotten the name of the story and recently wondered about the name... 10x WhiningKhan

 

[Grall]

afaik , it started as small story, and years later he made it to a novel.

Wasn't that the story about a world orbiting 5 suns, when all of them would dip below the horizon all at the same time...?

I know that one was a short story at first, and then he made it into a novel together with some other guy I believe. Can't remember the name of it though. Never read the book, but the short story was great.

Interesting parallel to this very thread:
Some (or even most?) of the stars of the short story were red giants (as Betelgeuse is a red giant), and the two main characters are astronomers... Pretty cool.