"Since its rotational axis is not toward the Earth, Betelgeuse's supernova would not cause a gamma ray burst in the direction of Earth large enough to damage its ecosystem even from a relatively close proximity of 520 light years."
Also it would take 520 years to get here anyway...
But I suppose that makes no difference because the first we'd know about it would be the gamma burst. What we're really discussing here is "Has Betelgeuse already gone Boom?"
No, no, no, the first way to tell if a star has already gone supernova is by the change in graviton waves.
I know you are trying to be funny but if there are gravity waves (possibly transmitted by gravitons) they would still arrive at the speed of light much like the visible and other EM radiation with very little lead time, if any. These are predicted by General Relativity and as such cannot violate relativity's golden "no information faster than light" causality rule. Even if the current gravity wave detectors were sensitive enough to detect any gravity waves it would be an after the fact detection since it takes thme time to analyse the data and so they would undoubtedly use the visible artifact to search a region of data carefully.
Of course all this only applies to vacuum. For example, the light of the sun needs much longer from the center of the sun to its surface, than from the surface to the earth, despite the fact that the first distance is much shorter.
I don't know where exactly gamma ray bursts are produced during a supernova, but if there's a substantial matter in between, I could imagine that they take longer than gravitational waves (gravitational waves might also be affected, but since their interaction with matter is much
The fact that light from the core takes a lot more time to reach the surface than from the surface to the earth has a completely different reason.
In fact, neutrinos aren't massless which means they are slower than light. The only reason the neutrinos arrived first is because of the way supernovas work. The neutrinos get emitted as soon as the core collapses but the first visible light only appears as soon as the shockwave from the collapse gets to the surface.
p>But a serious question: Over distance, wouldn't the visible light catch up to the neutrinos?
Sure, but over what distances are we speaking here? A neutrino created in a supernova would go about a trillionth of a meter per second slower than light, so even if they did a race across the universe( 80 billion lightyears), the neutrino would only be 60 km behind!
Neutrinos arrived about three hours before visible light
True - but unless things have improved dramatically since I last heard a talk from LIGO it would need to arrive days, weeks or even months in advance! Gravity wave detectors measure vibrations and have to have an incredibly complex understanding of their noise. This takes time.
The problem is that the weakness of gravitation compared to electromagnetism and that there is a lot of mass-energy distributed over the sky that we don't see at all (because it does not experience electromagnetism) or that we don't see very well (diffuse gas that has thermalized with the CMBR).
The latter introduces an unknown amount of noise if it isn't as diffuse as expected, particularly if stellar and even planetary DM halos are pervasive and dynamic. If the mass-energy is largely diffuse between the s
Money will say more in one moment than the most eloquent lover can in years.
Nova Post! (Score:4, Funny)
Boom!
Re: (Score:3, Interesting)
Seriously - If it goes supernova we should be a bit worried because it's close enough to drown us with radiation.
If that happens all our petty bickering on this planet will seem insignificant.
Of course - it's not certain that the radiation will be strong enough to kill off all life, but things will probably change a lot.
Re: (Score:5, Informative)
http://en.wikipedia.org/wiki/Betelgeuse [wikipedia.org]
Re: (Score:2)
Also it would take 520 years to get here anyway...
But I suppose that makes no difference because the first we'd know about it would be the gamma burst. What we're really discussing here is "Has Betelgeuse already gone Boom?"
Re: (Score:3, Funny)
because the first we'd know about it would be the gamma burst
No, no, no, the first way to tell if a star has already gone supernova is by the change in graviton waves.
Just need to finish figuring out how to detect those... maybe if we supply more power to the lateral sensor array...
Gravity Waves (Score:2, Informative)
No, no, no, the first way to tell if a star has already gone supernova is by the change in graviton waves.
I know you are trying to be funny but if there are gravity waves (possibly transmitted by gravitons) they would still arrive at the speed of light much like the visible and other EM radiation with very little lead time, if any. These are predicted by General Relativity and as such cannot violate relativity's golden "no information faster than light" causality rule. Even if the current gravity wave detectors were sensitive enough to detect any gravity waves it would be an after the fact detection since it takes thme time to analyse the data and so they would undoubtedly use the visible artifact to search a region of data carefully.
Re: (Score:0)
Of course all this only applies to vacuum. For example, the light of the sun needs much longer from the center of the sun to its surface, than from the surface to the earth, despite the fact that the first distance is much shorter.
I don't know where exactly gamma ray bursts are produced during a supernova, but if there's a substantial matter in between, I could imagine that they take longer than gravitational waves (gravitational waves might also be affected, but since their interaction with matter is much
Re: (Score:3, Interesting)
The fact that light from the core takes a lot more time to reach the surface than from the surface to the earth has a completely different reason.
In fact, neutrinos aren't massless which means they are slower than light. The only reason the neutrinos arrived first is because of the way supernovas work. The neutrinos get emitted as soon as the core collapses but the first visible light only appears as soon as the shockwave from the collapse gets to the surface.
Disclaimer: I'm not yet an astrophysicist, but I
Re: (Score:2)
>> I'm not yet an astrophysicist, but I did ace my cosmology exam yesterday
What does "50 ways to please your man." have to do with astrology?
But a serious question: Over distance, wouldn't the visible light catch up to the neutrinos?
Re: (Score:2)
p>But a serious question: Over distance, wouldn't the visible light catch up to the neutrinos?
Sure, but over what distances are we speaking here? A neutrino created in a supernova would go about a trillionth of a meter per second slower than light, so even if they did a race across the universe( 80 billion lightyears), the neutrino would only be 60 km behind!
Re: (Score:2)
Now I'm no astrophysicist, so I cannot tell if any of those possibilities applies.
Why is it that when I read that, I imagined you saying it in an "aw shucks" Matlock style:
"Now, ya Honor.... I ain't one of them big city Astrophysicists...."
Re: (Score:2)
Neutrinos arrived about three hours before visible light
True - but unless things have improved dramatically since I last heard a talk from LIGO it would need to arrive days, weeks or even months in advance! Gravity wave detectors measure vibrations and have to have an incredibly complex understanding of their noise. This takes time.
Re: (Score:0)
The problem is that the weakness of gravitation compared to electromagnetism and that there is a lot of mass-energy distributed over the sky that we don't see at all (because it does not experience electromagnetism) or that we don't see very well (diffuse gas that has thermalized with the CMBR).
The latter introduces an unknown amount of noise if it isn't as diffuse as expected, particularly if stellar and even planetary DM halos are pervasive and dynamic. If the mass-energy is largely diffuse between the s