Thoughtful question about the sun

[Eeezee]

In a fictional universe, yes, we would just not know for a few minutes.

Fortunately astronomy is already a well-developed field, so we'll know when the sun is going to "go out" or "explode" at least several thousand years before that event actually happens. For those sitting around on the Earth at that time, they will have to wait 8 minutes before they notice anything.

A much more cool realization is that you can look up at the night sky and be seeing light that is millions, billions of years old. Astronomers recently announced that they've observed several billion year old light (the oldest light known) from a galaxy formed in the early universe.

 

[wtfbbq]

depending on the situation, we would know beforehand. i remember a particle physicist who told me that some of the reactions in the sun shoot out particles (neutrinos or muons or something else, I forgot), so those would stop hitting earth before the light waves did (so the particles' reaction would be stopped before light stops being emitted).

i can't really remember it very well at all, maybe someone with more knowledge knows what i'm talking about?

 

[Eeezee]

Originally posted by: wtfbbq
depending on the situation, we would know beforehand. i remember a particle physicist who told me that some of the reactions in the sun shoot out particles (neutrinos or muons or something else, I forgot), so those would stop hitting earth before the light waves did (so the particles' reaction would be stopped before light stops being emitted).

i can't really remember it very well at all, maybe someone with more knowledge knows what i'm talking about?

Neutrinos travel at the speed of light too. We'd stop getting hit by neutrinos and photons (light) at the same time. In fact, the neutrinos are being created in the reactions that are "creating" the light.

Also, solar neutrinos are only a fraction of the neutrinos that pass through the Earth daily. Neutrinos interact very weakly, so A) they are hard to detect (the best neutrino detectors only have a few detections per day) and B) they can come from pretty much anywhere, including extragalactic sources (billion year-old neutrinos are passing through your body right now!)

The reaction stopping = no more neutrinos or photons, but since they both travel at the speed of light it will still take 8 minutes for those last neutrinos to reach you.

 

[wtfbbq]

Originally posted by: Eeezee

Originally posted by: wtfbbq
depending on the situation, we would know beforehand. i remember a particle physicist who told me that some of the reactions in the sun shoot out particles (neutrinos or muons or something else, I forgot), so those would stop hitting earth before the light waves did (so the particles' reaction would be stopped before light stops being emitted).

i can't really remember it very well at all, maybe someone with more knowledge knows what i'm talking about?

Neutrinos travel at the speed of light too. We'd stop getting hit by neutrinos and photons (light) at the same time. In fact, the neutrinos are being created in the reactions that are "creating" the light.

Also, solar neutrinos are only a fraction of the neutrinos that pass through the Earth daily. Neutrinos interact very weakly, so A) they are hard to detect (the best neutrino detectors only have a few detections per day) and B) they can come from pretty much anywhere, including extragalactic sources (billion year-old neutrinos are passing through your body right now!)

The reaction stopping = no more neutrinos or photons, but since they both travel at the speed of light it will still take 8 minutes for those last neutrinos to reach you.

yeah, i was thinking about that, but i distinctly recall him saying they would stop first. which is why i thought it would depend on the situation (i.e. how the star died). maybe i'm just making all this up... it was a while ago, and i (both then and now) dont know much about astrophysics...

 

[Orsorum]

It won't matter when the sun "goes out" because by that point it will have gone through its red giant phase and burned Earth to a crisp.

 

[JTsyo]

Even if the Sun went nova, the mass would still be there so there wouldn't be much of a change in gravity.

 

[Kelemvor]

What about gravity. How fast does that travel?

If the sun just were gone instantly, would the earth hurtle off into space right away or would that take a bit to happen too?

 

[Shlong]

Originally posted by: Kelemvor
What about gravity. How fast does that travel?

If the sun just were gone instantly, would the earth hurtle off into space right away or would that take a bit to happen too?

It would take a few minutes for earth to hurtle off into space.

 

[ShadowOfMyself]

That telescope thing is really weird... So if some species in a far away galaxy had a telescope powerful enough to see Earth with some detail, depending on the distance, they could see back to the age of dinossaurs? Crazy stuff!

 

[FoBoT]

http://metaresearch.org/cosmology/speed_of_gravity.asp

ouch ouch ouch, that made my brain hurt

Conclusion: The Speed of Gravity is >= 2x10^10 c

Using the same equation with binary pulsar PSR1534+12 and the parameters in Table I, we can place the most stringent limit yet from the observed uncertainty in : >= 2x10^10 c

i am not sure what that means

 

[darkxshade]

I think we would see the sun explode within 8 mins but I'm sure we have a lot of time before the explosion hits us.

 

[Aharami]

lets say the Sun didnt explode or go Nova. Lets say it just stopped existing - like it was teleported to another point in space. Would Earth go off straight in a tangent whereever it is in its orbital path 8 mins after the sun disappeared? What will happen to life on Earth w/o the Sun? Undoubtedly, life will cease to exist, but how long could life cling on for?

Originally posted by: ShadowOfMyself
That telescope thing is really weird... So if some species in a far away galaxy had a telescope powerful enough to see Earth with some detail, depending on the distance, they could see back to the age of dinossaurs? Crazy stuff!

yea. crazy stuff indeed. and the Universe isnt as we see it right now. We see it as it used to be many many many years ago

 

[darkxshade]

Originally posted by: Aharami
lets say the Sun didnt explode or go Nova. Lets say it just stopped existing - like it was teleported to another point in space. Would Earth go off straight in a tangent whereever it is in its orbital path 8 mins after the sun disappeared? What will happen to life on Earth w/o the Sun? Undoubtedly, life will cease to exist, but how long could life cling on for?

Originally posted by: ShadowOfMyself
That telescope thing is really weird... So if some species in a far away galaxy had a telescope powerful enough to see Earth with some detail, depending on the distance, they could see back to the age of dinossaurs? Crazy stuff!

yea. crazy stuff indeed. and the Universe isnt as we see it right now. We see it as it used to be many many many years ago

I'll leave it to the experts to explain this but I do believe the 8 min thing is how long it would take the light from the sun to reach earth hence we see what's happening 8 mins after the fact but any side effect from whatever events won't be felt until much later imo(not sure how long). This is of course my assumption that nothing can beat the speed of light and no matter how fast events are happening, it won't reach us before the visuals of the event.

 

[Safeway]

Originally posted by: darkxshade
I think we would see the sun explode within 8 mins but I'm sure we have a lot of time before the explosion hits us.

Negative. Supernova send out mass and energy at near-light speed.

 

[Safeway]

And yes, the speed is gravity is equal to the speed of light.

 

[shocksyde]

If you like your mind blown, check out "Death by Black Hole" by Tyson. Mmmmm. Mind-melting!

 

[darkxshade]

Originally posted by: Safeway

Originally posted by: darkxshade
I think we would see the sun explode within 8 mins but I'm sure we have a lot of time before the explosion hits us.

Negative. Supernova send out mass and energy at near-light speed.

really? wow, I was not aware a supernova would be capable of that.

 

[Pollock]

Originally posted by: Aharami
lets say the Sun didnt explode or go Nova. Lets say it just stopped existing - like it was teleported to another point in space. Would Earth go off straight in a tangent whereever it is in its orbital path 8 mins after the sun disappeared? What will happen to life on Earth w/o the Sun? Undoubtedly, life will cease to exist, but how long could life cling on for?

Per Elegant Universe, the speed of light is like a universal speed limit. Nothing can go faster. If the sun suddenly exploded or something, Newtonian physicists figured the earth would instantaneously fly off, but since gravity travels at like (maybe the exact same, I can't remember) the speed of light, that wouldn't occur until the light of the event reached us. That's something that Einstein figured out, I guess. Would we be obliterated at the same time? Beats me.

 

[Kelemvor]

I like the sun. I hope it sticks around for a while...