Betelgeuse To Go Supernova

[Wild Bill]

"Betelgeuse! Betelgeuse! BETELGEUSE!"

Just thought I'd bring him back!

[jdobbin]

Either way...when it does blow (with 'luck', in our lifetime, which is begining to seem likely due to the rapid shrinkage) the explosion will dominate the night and daytime sky.

For those unaware how large this star is, refer to this star comparison diagram for a bit of a surprise. Betelgeuse is one of the few stars we can resolve into as disc from Earth it is so large and 'close'...for a star.

I wonder how long that would last with the brightness.

I always get a kick out of the star comparisons. The sheer size simply overwhelms.

[Bonam]

I wonder how long that would last with the brightness.

I always get a kick out of the star comparisons. The sheer size simply overwhelms.

Not long, usually on the timescale of days, depending on the nature of the explosion. Supernovas are remarkably fast and sudden things, considering how slow (by our timescales) the rest of the stellar evolution process is.

[DogOnPorch]

Crap...thought it exploded.

Better in winter anyways, for Canadians.

[GostHacked]

Ah well! Nice to meet you. Space flight is a passion of mine as well. Ion drives and such? Space sails?

Have you tried Orbiter? I'm involved in that project.

http://orbit.medphys.ucl.ac.uk/orbit.html

I was amazed about 6 years ago to find out that the Ion drive exists. Although on a space probe, but hot damn if that isn't cool. Like I mean I build them all the time in Homeworld , but to know it actually exists, feels like we are zoomin up that tech tree.

[DogOnPorch]

I was amazed about 6 years ago to find out that the Ion drive exists. Although on a space probe, but hot damn if that isn't cool. Like I mean I build them all the time in Homeworld , but to know it actually exists, feels like we are zoomin up that tech tree.

I believe Bonam has some experience in the field.

[Bonam]

I believe Bonam has some experience in the field.

Yup it's what my master's research is on.

[CANADIEN]

If Betelgeuse is 600 light-years away, aything we see now has already happened... 600 years ago.

[DogOnPorch]

If Betelgeuse is 600 light-years away, aything we see now has already happened... 600 years ago.

Gosh...really?

[Bonam]

If Betelgeuse is 600 light-years away, aything we see now has already happened... 600 years ago.

Actually that is a flawed concept, arising from a lack of understanding of the principles of relativity. There is no absolute time frame in which to define simultaneity. For us, what we see happening on Betelgeuse, is what is happening NOW, for us, because any possible effects of the occurrence can only be felt now. One can do a thought experiment where one instantly transports themselves to Betelgeuse and from there observes that the events we are now seeing on Earth are 600 years old, but this is impossible in practice. For an observer on Earth, the only present is the present that is observable from Earth.

Anyway my words are hopelessly inadequate to what I'm trying to explain I guess, relativity takes a bit of time to explain and to wrap one's head around.

But the concept is to do with the relativity of simultaneity.

[Wild Bill]

Actually that is a flawed concept, arising from a lack of understanding of the principles of relativity. There is no absolute time frame in which to define simultaneity. For us, what we see happening on Betelgeuse, is what is happening NOW, for us, because any possible effects of the occurrence can only be felt now. One can do a thought experiment where one instantly transports themselves to Betelgeuse and from there observes that the events we are now seeing on Earth are 600 years old, but this is impossible in practice. For an observer on Earth, the only present is the present that is observable from Earth.

Anyway my words are hopelessly inadequate to what I'm trying to explain I guess, relativity takes a bit of time to explain and to wrap one's head around.

But the concept is to do with the relativity of simultaneity.

I'm still wrapping my head around it, and I first read about it when I was 12 years old!

I think I was 16 when it broke my heart. With no common frame of reference for time and no common elapsed rate between frames, I realized there could never be a United Federation of Planets!

You could schedule a meeting at Federation HQ for October 4, 2250. You give everyone 4 weeks notice. NOBODY would have a chance of being on time! A month on one planet in one frame of reference could be several months on another, or days, or literally any time period, depending on the vector speed and direction between HQ and that planet.

Yet WITHIN EACH FRAME it would seem to be 4 weeks! Only when you arrive in another frame would the difference show up.

This is bad enough between two planets. How about for a hundred of them?

Mr. Spock could serve 5 years in Star Fleet and come home to find 50 years had passed!

Edited July 29, 2009 by Wild Bill

[M.Dancer]

Actually that is a flawed concept, arising from a lack of understanding of the principles of relativity. There is no absolute time frame in which to define simultaneity. For us, what we see happening on Betelgeuse, is what is happening NOW, for us, because any possible effects of the occurrence can only be felt now.

Never the less, the light from Betelgeuse takes 600 years to reach us so it did happen in the past...much like a band concert I went to decades ago where the sound system failed...I could see the drummer hit his bass but only hear the bass a second later.

[Wild Bill]

Never the less, the light from Betelgeuse takes 600 years to reach us so it did happen in the past...much like a band concert I went to decades ago where the sound system failed...I could see the drummer hit his bass but only hear the bass a second later.

Failed analogy. If nothing can exceed the speed of light there's no way for you to receive any info 600 years before you see it happen.

Happen in the past? Who's past? THAT'S the point! It's as valid to assume the present is NOW on Betelgeuse as it is this moment here on Earth.

[M.Dancer]

Failed analogy. If nothing can exceed the speed of light there's no way for you to receive any info 600 years before you see it happen.

So when the fastest Information could travel was by sailing ship, the death of Wolfe and Montcalm happened at the same moment as the Admiralty in London received word of the death?

[Bonam]

So when the fastest Information could travel was by sailing ship, the death of Wolfe and Montcalm happened at the same moment as the Admiralty in London received word of the death?

The fastest information can travel has always been the speed of light. Human technological capabilities are beside the point.

[M.Dancer]

The fastest information can travel has always been the speed of light. Human technological capabilities are beside the point.

Agreed...speed of light+ distance, time for light to travel...event happened 600 years ago

[Bonam]

Agreed...speed of light+ distance, time for light to travel...event happened 600 years ago

In Betelgeuse's timeframe, yes. But we aren't at Betelgeuse. We're on Earth. For us, the event is only happening now.

[M.Dancer]

In Betelgeuse's timeframe, yes. But we aren't at Betelgeuse. We're on Earth. For us, the event is only happening now.

It seems like it's happening now, but it isn't. It did infact happen in the past. Much like a solar flare..we observe it now but are conscious of the fact it happened 8 minutes ago.

[DogOnPorch]

The joys of relativity.

[Jerry J. Fortin]

Everybody here sure that there is no wobble in the axis of the star in question? If there is then a different answer will be found.

[Bonam]

It seems like it's happening now, but it isn't. It did infact happen in the past. Much like a solar flare..we observe it now but are conscious of the fact it happened 8 minutes ago.

Sure we "know" that in the sun's timeframe, the flare occurred 8 minutes ago. But that's a different timeframe, not ours. There is nothing special about the sun's timeframe, nor does it become more special when you are talking about a solar flare. Our timeframe is just as good, the laws of physics are the same in it, and from that point of view it is happening now. For any observer, the observable present is the surface of the past light cone, as represented on a spacetime diagram.

The Sun is a good example to consider. Imagine that the Sun suddenly disappeared, just went poof and wasn't there anymore. For the next 8.5 minutes, we would still see its light. Indeed, the Earth would continue its curved orbit, gravitationally attracted to an object that "isn't there any more", for the next 8.5 minutes. Only then would the information, both electromagnetic and gravitational, reach the Earth, and then we would see the sun disappear and the Earth would fly off on a straight line path. But how can we orbit an object that doesn't exist? We can't, and the answer is that in our timeframe, the object still exists. In our present, as observed from Earth, the Sun continues to exist until we observe that it no longer exists. Meanwhile, an observer, say, on Mars, would still think that the Sun exists - his present is different than our present.

But meh, no use arguing concepts of relativity here really. Can go to the physics forums for that ;p

[M.Dancer]

The Sun is a good example to consider. Imagine that the Sun suddenly disappeared, just went poof and wasn't there anymore. For the next 8.5 minutes, we would still see its light. Indeed, the Earth would continue its curved orbit, gravitationally attracted to an object that "isn't there any more", for the next 8.5 minutes. Only then would the information, both electromagnetic and gravitational, reach the Earth, and then we would see the sun disappear and the Earth would fly off on a straight line path. But how can we orbit an object that doesn't exist? We can't, and the answer is that in our timeframe, the object still exists.

Sort of like when I water the grass with the hose..a long arcing stream of water courses over the lawn, then I let go of the handle and the water ceases to come out of the gun..yet the arc continues on its way, propelled by the water pressure that no longer applies. It's not that in the time frame of the arcing water the pressure exists...only it's energy expended still exists. The gravitational force that keeps us in orbit is 8 minutes old....

[Bonam]

The gravitational force that keeps us in orbit is 8 minutes old....

Gravity is the curvature of spacetime, not really a "force". At our position and in our timeframe, the spacetime remains curved in the same way as it was while the sun existed, until the sun no longer exists in our timeframe, at which time the propagation of the gravitational wave that "flattens" the spacetime reaches us.

[GostHacked]

Gravity is the curvature of spacetime, not really a "force". At our position and in our timeframe, the spacetime remains curved in the same way as it was while the sun existed, until the sun no longer exists in our timeframe, at which time the propagation of the gravitational wave that "flattens" the spacetime reaches us.

Does this mean we only have one timeframe to observe in. So all other events will happen in our time frame, eventhought it happened in the past.

If Betelguese has gone supernova in the past, we won't know about it for some time. However if we were to be in two places at the same time. To earth, Betelguese would still exist, but if you were to observe it on a planet that was close by or in that system, they would see that Betelgues no longer exists.

It happened in the past, and it is taking 600 years for that observable light to reach our retinas. I am no science expert, but to me we can only observer what is in our time frame and speculate what the outcome will be. We have observed Betelguese enough to figure out what happened to the star. We can still see the light and say it exists, when in fact we know different.

Faster than light communications will eventually be possible.

[M.Dancer]

I am no science expert.....

Faster than light communications will eventually be possible.

Is that your no expert opinion?