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kfiscus
Carpal Tunnel
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Reged: 07/09/12

Loc: Albert Lea, MN, USA
Re: What would the sun appear if it exploded? new [Re: sickfish]
      #6479616 - 04/21/14 05:52 PM

You're dead and vaporized before you could squint. No thought, no pain, no fear, no problem. I read somewhere that we drastically over-estimate the speed that thought and pain travel. Pain sensations travel something like 130 mph, if I remember correctly.

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GlennLeDrew
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Reged: 06/18/08

Loc: Ottawa, Ontario, Canada
Re: What would the sun appear if it exploded? new [Re: chrisg]
      #6479632 - 04/21/14 06:02 PM

Whenever velocity becomes an appreciable fraction of light speed there must entail relativistic effects such as time dilation. Even at the paltry speed of 8km/s in Earth orbit, clocks (atomic, anyway) run at measurably different rates to those on the ground.

My eyepiece pair is the 13mm Ethos, which with my 60mm f/4.5 objectives delivers 20.8X at a spectacular 4.7 degrees.


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gdd
Pooh-Bah


Reged: 11/23/05

Loc: N Seattle suburb, WA
Re: What would the sun appear if it exploded? new [Re: GlennLeDrew]
      #6479687 - 04/21/14 06:25 PM

How about those observing the explosion blow by from the midnight sky, or from the far side of the moon should the explosion occur during a lunar eclipse?

Gale


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Achernar
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Re: How would the sun appear if it exploded? new [Re: chrisg]
      #6479692 - 04/21/14 06:26 PM

An average nova outbursts would flash vaporize and melt the Earth's crust, blow away the atmosphere and boil off the oceans. It goes without saying everything alive on the planet would die of vaporization, the planet would be heat sterilized. All of the other planets, asteroids would be similiary affected because a typical nova outburst shines at least 100,000 times brighter than the Sun. A supernova would not only boil off the surfaces and atmospheres of the planets, they would most likely hurtle off into space from the destruction of the Sun, or be ripped apart when the blast wave hits them at ten percent of the speed of light. You would see the photosphere flare up and then you're vapor. From that close, there would be little to see if the Sun exploded as a nova or supernova. The surge in x-rays and gamma rays would kill you eight minutes after the blast, long before the ejecta hits at least an hour and twenty minutes later.

Taras


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Noisykids
sage
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Reged: 06/01/11

Loc: ma
Re: How would the sun appear if it exploded? new [Re: Achernar]
      #6479709 - 04/21/14 06:32 PM

find and read The Year of the Jackpot. this is exactly what happens at the end.

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Mike B
Starstruck
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Reged: 04/06/05

Loc: shake, rattle, & roll, CA
Re: How would the sun appear if it exploded? new [Re: Noisykids]
      #6479749 - 04/21/14 06:58 PM

Quote:

The arrival of the photons and the gravitational effects (gravity waves) attending the event arrive/occur in step.



Well, according to one theory of gravity. But i'm not sure we really know for certain, just yet, re: the wave nature OR "speed" of gravitational propagation.

One piece i read a while ago stated that gravity, in all meaningful calculations, is assumed to have instantaneous effects... and when they try dialing in a lightspeed factor for gravitational effects, nothing "works" as it's s'posed to, according to the reality measured. (i'm no doubt butchering the guy's presentation, here... but this was his general idea )

We know what gravity does, and we measure its effects (that we know of, anyhoo) down to the "n"th degree... but we still don't know what it actually IS.


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Midnight Dan
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Re: How would the sun appear if it exploded? new [Re: Mike B]
      #6479785 - 04/21/14 07:16 PM

Wow! People are taking this one all over the place. What gets vaporized and when, relativistic speed effects, etc. The question is pretty simple. Would it appear to take less time than the actual duration, and would it appear to speed up or slow down as it nears Earth.

The answers are equally clear. Regardless of whether it's traveling at 1/2 light speed or at 10 miles an hour, it will appear to take 8 minutes less than the actual duration (although the actual duration may be affected by time dilation). And as long as the speed is constant, there is no slowing down or speeding up as it approaches Earth. The effect is linear.

The eyepiece question is, of course, open to debate, BUT ... I'm wearing sunglasses!

-Dan


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gdd
Pooh-Bah


Reged: 11/23/05

Loc: N Seattle suburb, WA
Re: How would the sun appear if it exploded? new [Re: Achernar]
      #6479806 - 04/21/14 07:35 PM

Quote:

An average nova outbursts would flash vaporize and melt the Earth's crust, blow away the atmosphere and boil off the oceans. It goes without saying everything alive on the planet would die of vaporization, the planet would be heat sterilized. All of the other planets, asteroids would be similiary affected because a typical nova outburst shines at least 100,000 times brighter than the Sun. A supernova would not only boil off the surfaces and atmospheres of the planets, they would most likely hurtle off into space from the destruction of the Sun, or be ripped apart when the blast wave hits them at ten percent of the speed of light. You would see the photosphere flare up and then you're vapor. From that close, there would be little to see if the Sun exploded as a nova or supernova. The surge in x-rays and gamma rays would kill you eight minutes after the blast, long before the ejecta hits at least an hour and twenty minutes later.

Taras





What would be the closest soemwhat safe viewing location?

Gale


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mrchunks
member


Reged: 03/23/14

Re: What would the sun appear if it exploded? new [Re: Midnight Dan]
      #6479864 - 04/21/14 08:09 PM

maybe I missed the point,
at timepoint 1:08 and 1:12 would not the light from the 1/2 waypoint and the 3/4 point arrive at the same time?
if the surface were 1/2 way or 3/4 way closer to earth would the light coming from it would precede the light that came from it initially ????

my head hurts


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palmer570
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Reged: 09/04/12

Loc: Scranton, Pennsylvania
Re: What would the sun appear if it exploded? new [Re: mrchunks]
      #6479994 - 04/21/14 09:19 PM

The light from 1/2 and 3/4 waypoints will not arrive at the same time. No matter how fast or slow a object is travelling light emitted from it will always be the same speed.

At 1/2, 1:08, it would take the light ~4 mins to reach us, 1:12

At 3/4, 1:12, it would take the light ~2 mins to reach us, 1:14

Not sure what you're asking in the second question. If the surface instantly moved 1/2 closer then yes that light would arrive ~4mins before the light from the original position.


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Mike B
Starstruck
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Reged: 04/06/05

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Re: What would the sun appear if it exploded? new [Re: mrchunks]
      #6479996 - 04/21/14 09:20 PM

Quote:

my head hurts



Yeah, supernova's will do that...



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Mentor
professor emeritus


Reged: 09/30/10

Loc: Ontario, Canada
Re: What would the sun appear if it exploded? new [Re: palmer570]
      #6480038 - 04/21/14 09:39 PM

As astronomers we should all be familiar with the redshift of electromagentic radiation as objects receede from an observer. In the example in question, the radiation would be blueshifted as the source is advancing towards the observer at a relativistically significant rate. The speed of light remains constant, the wavelength will change.

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Midnight Dan
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Re: What would the sun appear if it exploded? new [Re: palmer570]
      #6480163 - 04/21/14 10:40 PM

Quote:

The light from 1/2 and 3/4 waypoints will not arrive at the same time. No matter how fast or slow a object is travelling light emitted from it will always be the same speed.

At 1/2, 1:08, it would take the light ~4 mins to reach us, 1:12

At 3/4, 1:12, it would take the light ~2 mins to reach us, 1:14

Not sure what you're asking in the second question. If the surface instantly moved 1/2 closer then yes that light would arrive ~4mins before the light from the original position.






-Dan


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chrisg
sage
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Reged: 02/15/09

Re: What would the sun appear if it exploded? new [Re: Mentor]
      #6480290 - 04/22/14 12:05 AM

Quote:

As astronomers we should all be familiar with the redshift of electromagentic radiation as objects receede from an observer. In the example in question, the radiation would be blueshifted as the source is advancing towards the observer at a relativistically significant rate. The speed of light remains constant, the wavelength will change.




That was going to be my second question but I was hesitant to inflict further brain damage on this fine group!
Wikipedia says that a supernova expels material at approx 1/10th the speed of light, or 30,000 km/s. So I'm wondering how blue would the approaching blob of death appear, assuming that the sun would actually end in a supernova. (I don't know what the accepted theory is here, I'm more interested in the hypothetical example)


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penguinx64
Pooh-Bah


Reged: 11/12/13

Loc: Holland
Re: What would the sun appear if it exploded? new [Re: chrisg]
      #6480534 - 04/22/14 04:26 AM

If the Sun explodes, what kind of filter should I use?

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darren38
member


Reged: 04/02/14

Loc: Burlington, Vermont
Re: What would the sun appear if it exploded? new [Re: chrisg]
      #6480559 - 04/22/14 05:12 AM

We would be dead long before any kind of explosion would take place. As the sun's core begins to fail, it slowly expands outward through the solar system, and I mean slowly. It would envlope the planets, like a hungry giant. If there was an explosion, and I think with our size star, there would not be, we would be long vaporized before. I believe, but I am not an expert.

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darren38
member


Reged: 04/02/14

Loc: Burlington, Vermont
Re: What would the sun appear if it exploded? new [Re: darren38]
      #6480560 - 04/22/14 05:16 AM

here is a pretty cool article, with some pretty cool art work. http://io9.com/5871387/what-will-happen-when-the-sun-dies

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Mentor
professor emeritus


Reged: 09/30/10

Loc: Ontario, Canada
Re: What would the sun appear if it exploded? new [Re: chrisg]
      #6480724 - 04/22/14 08:27 AM

Quote:

That was going to be my second question but I was hesitant to inflict further brain damage on this fine group!
Wikipedia says that a supernova expels material at approx 1/10th the speed of light, or 30,000 km/s. So I'm wondering how blue would the approaching blob of death appear, assuming that the sun would actually end in a supernova. (I don't know what the accepted theory is here, I'm more interested in the hypothetical example)




The formula is simple. Given the assumptions presented (i.e. supernova expanding at 1/10 c), f' = f (1 + V/c), so f' = 1.1f. With a yellow star we can assume f = 500 THz, so f' = 550 THz, right in the green part of the visible electromagnetic spectrum.


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swix
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Reged: 03/25/12

Loc: Maryland
Re: What would the sun appear if it exploded? new [Re: chrisg]
      #6480830 - 04/22/14 09:32 AM

Say a quick goodbye...

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csrlice12
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Reged: 05/22/12

Loc: Denver, CO
Re: What would the sun appear if it exploded? new [Re: penguinx64]
      #6480847 - 04/22/14 09:43 AM

Quote:

If the Sun explodes, what kind of filter should I use?




the KYAGB filter, of course.


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