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Comment by adrianN | Hacker News Reader

Somebody is getting close to completing their Dyson sphere?

Good luck dyson sphering that star :)

It's massive and very violent! It might be that this violence is causing the dimming by discharging massive amounts of dust and gas.

I hope it's a prelude to fireworks but that is unfortunately not probable.

I just hope that there is nobody wanting our sun to explode for scientific curiosity.

Betelgeuse can not sustain life and it _will_ blow up very soon in cosmic timescales. There is nothing we do to stop it blowing up so yes, I hope to see this event in my lifetime :)

Our sun is much more stable.

How can you know that?

I mean, you're probably correct, but given we have precisely one datapoint for life, it's a bit much to extrapolate further - there might be aeons-old silicon-skinned space whales congregating around Betelgeuse for their thrice giga-millennial spawning season, or something... . Probably not.

- ed

'thrice kilo or mega millennial' seems a bit less unlikely!

Well, disregarding radiation resistant space whales (which would be able to migrated to another star anyway), I think it's pretty clear the radiation and onslaught of solar winds from Betelgeuse will sterilise everything in the vicinity.

But you are right, nothing can be ruled out ;)

If we're talking hypotheticals, a tidally locked planet would lose its volatiles pretty quickly, but one could in theory bunker up on the far side of the planet and survive.

But you'd be stuck there forever, right? Diffraction means that the shadow only goes out so far before you're being cooked again by one form of particle or another.

Giant stars are quite short-lived, with Betelgeuse estimated to have at most a 15 million (not billion!) year life before becoming a red supergiant . If simple life did evolve in time, it was wiped out about 100,000 years ago as Betelgeuse became a supergiant.

One last fun fact: Betelgeuse is about 125,000 times brighter than the Sun in absolute luminosity.

Well if Betelgeuse explodes, it technically already happened back in the middle ages and we are only just now seeing it.

I've started finding this sort of comment very irritating since I've converted to the idea that everything on the surface of a light cone is simultaneous.

The meaning of the so called "relativity of simultaneity" appears to me to be that you just shouldn't talk about simultaneous events with spacelike separation.

If you agree that you can say Betelgeuse is far away without someone objecting with "only in a reference frame that isn't close to it!" then you should also agree that there is an implied set of reference frames that are reasonable to use in the interpretation of comments written on Earth. In the same way that "Betelgeuse is far away" means "Betelgeuse is far away from me," the claim that "an event on Betelgeuse that we are observing today happened in the Middle Ages" means that "an event on Betelgeuse that we are observing today happened in the Middle Ages from a reference frame comoving with anyone on Earth."

This is probably the last star you would want your Dyson sphere on.

Which makes it the perfect star to cover with a Dyson sphere. What better way to flex on your interstellar neighbors than by harnessing one of the most powerful, violent things in nature?

I think the point being made is the size of it. To make it into a Dyson sphere would require encasing a star that, if centered on Sol, would consume at least the inner 4 planets if not Jupiter as well. It's 950 times the size of our own star and one of the largest in the known universe. There would surely be easier supernova-capturing flexes

"Four intergalactical-capable factions are trying to decide who holds the most power. In an average galaxy in a pretty anonymous corner of the universe one faction detects a unprecedented large star-about-to-go-nova and races to capture the imminent energy surge of a sort the universe hasn't experienced yet. Or will the galaxy implode before they have aligned it all."

A back cover blurb I wouldn't mind picking up! If something like this is already written I want to know.

Could be a one-shot Dyson Sphere designed to capture the energy of a supernova. Like an advanced civilization's version of a nuclear explosion-pumped X-ray laser[1]

[1] https://en.wikipedia.org/wiki/X-ray_laser

I think if you're at that level of technology you'd rather make sure that the star doesn't explode and eject a bunch of valuable fuel into deep space.

That would be an interesting thought exercise for brains better than mine: if you are a civilization capable of building a physical barrier around an entire stellar system, what is the best way to generate energy?

I wonder if it would be something to do with neutron stars or magnetars?

The best way I know is creating small artificial black holes, feeding them matter at just the right rate and harvesting the Hawking radiation. That's actually a lot easier than building a Dyson sphere.

https://arxiv.org/abs/0908.1803

I think that if you have the technology to capture the energy of a supernova you probably don't need to capture it.

Maybe we're all wrong and a nearby civilization just wants to contain the supernova explosion...

If you were next door and you had magic infinitely strong materials, you might want to Dyson-sphere it before it explodes (this dubious concept is found in a number of pieces of science fiction).

No need for a Dyson sphere.

Theoretically, you could place a relatively small, dense object fairly close to Betelgeuse and protect your entire stellar neighborhood. I haven't done the math, but I suspect it would have to be so small and dense that it would be a black hole.

You'd probably be better off just trying to shield your planet from whatever lesser energies eventually arrive.

If I wanted to build Dyson sphere I would choose a star with longer estimated lifetime for bigger bang for the buck. Maybe dwarf star to save on building materials?

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