What happens when Betelgeuse explodes? • Hacker News Board

To me one is imperceptible and the other is hard to reason about as a whole (of course I can make use of an abstract idea of a year, but imagine the experiences of a year all at once? Nope.)

Re: What happens when Betelgeuse explodes?

#15

Post by themartorana » Wed, Feb 25, 2015, 1:03 PM UTC

astletron wrote: post #2

"Nighttime will be a different story. The brightness of Betelgeuse’s supernova is about the same as the quarter moon." This will last maybe a couple of weeks, but we don't expect it for 100K years.

No, but with billions of stars in our own galaxy, and more beyond, wouldn't (my misunderstanding of) the probability of witnessing a past supernova event during one's lifetime be higher than it feels like it is?

Re: What happens when Betelgeuse explodes?

#16

Post by onion2k » Wed, Feb 25, 2015, 1:22 PM UTC

themartorana wrote: post #15

astletron wrote: post #2

"Nighttime will be a different story. The brightness of Betelgeuse’s supernova is about the same as the quarter moon." This will last maybe a couple of weeks, but we don't expect it for 100K years.

No, but with billions of stars in our own galaxy, and more beyond, wouldn't (my misunderstanding of) the probability of witnessing a past supernova event during one's lifetime be higher than it feels like it is?

Not really. There are a huge number of stars, but most of them are moving away so fast that the light from their death wouldn't ever reach us, and their light would be shifted in to parts of the spectrum we can't see. Similar to Olbers' Paradox - http://en.wikipedia.org/wiki/Olbers%27_paradox

Re: What happens when Betelgeuse explodes?

#17

Post by d_theorist » Wed, Feb 25, 2015, 1:56 PM UTC

"Betelgeuse is already one of the brightest stars in the night sky, sitting somewhere around the 8th or 9th brightest star in the night sky. (These lists don’t include the Sun, which is somewhat obviously always the brightest object in the sky.)"

A good point, although it is fairly rare to see the sun in the night sky these days.

Re: What happens when Betelgeuse explodes?

#18

Post by aruggirello » Wed, Feb 25, 2015, 2:13 PM UTC

kijin wrote: post #9

Other than slightly brighter-than-normal nights, will there be any adverse effects on Earth? The wikipedia article on near-Earth supernovae [1] suggests that Betelgeuse will be pretty safe because of its distance. But exactly how safe? What about all the delicate electronics that we've sent up to space? I suppose anything that can withstand a daily dose of solar radiation would probably be okay, but are there any spe…

Actually, a supernova would look like an impossibly tiny point source, much smaller than even your average laser pointer. I'm pretty sure the consequences of this haven't been thoroughly explored yet.

I'm not sure the Betelgeuse supernova, at a brightness around that of the full moon, would ignite fires, but I certainly wouldn't want to gaze at it with naked eyes, even at that brightness. IMHO such a light, given sufficient strength, could permanently damage the retina in your eyes.

Re: What happens when Betelgeuse explodes?

#19

Post by mabbo » Wed, Feb 25, 2015, 2:15 PM UTC

onion2k wrote: post #16

themartorana wrote: post #15

Earlier quoted context omitted.

No, but with billions of stars in our own galaxy, and more beyond, wouldn't (my misunderstanding of) the probability of witnessing a past supernova event during one's lifetime be higher than it feels like it is?

Not really. There are a huge number of stars, but most of them are moving away so fast that the light from their death wouldn't ever reach us, and their light would be shifted in to parts of the spectrum we can't see. Similar to Olbers' Paradox - http://en.wikipedia.org/wiki/Olbers%27_paradox

> most of them are moving away so fast that the light from their death wouldn't ever reach us

Correct me if I'm wrong, but I believe that's mistaken. Given enough time, even things moving away from us at the speed of light will eventually be seen by us. http://en.wikipedia.org/wiki/Ant_on_a_rubber_rope

Re: What happens when Betelgeuse explodes?

#20

Post by amoruso » Wed, Feb 25, 2015, 2:22 PM UTC

This article reminded me of something I read a few years ago. What is it like to be really near a supernova? It's a quick read and entertaining too.

Life (Briefly) Near a Supernova:

http://www.nagt.org/files/nagt/jge/abstracts/Dutch_v53n1.pdf