Betelgeuse going supernovae

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

 

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

 

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.

 

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.

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).

 

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.

 

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

 

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).

 

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

 

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

 

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.

 

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.

 

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.

 

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.

 

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

 

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.