You are not logged in. [Login] Entrance · Main Index · Search · New user · Who's Online FAQ · Calendar

General Astronomy >> Beginners Forum

Pages: 1 | 2 | 3 | 4 | (show all)
chrisg
sage

Reged: 02/15/09

How would the sun appear if it exploded?
#6478029 - 04/20/14 08:38 PM

Perhaps this isn't how the sun will die, but this question has always puzzled me. Given that it takes light about 8 minutes to reach us at it's current distance, how would the sun's explosion appear as this distance decreases? Mucho apologies for the grim exercise!

Edited by chrisg (04/21/14 12:44 AM)

 Post Extras:
AustinAstronomer
sage

Reged: 03/04/10

Re: What would the sun appear if it exploded? [Re: chrisg]
#6478115 - 04/20/14 09:33 PM

I don't understand your question. If the sun exploded, you would see that explosion eight minutes later, and you would be vaporized about a second after that. In short, the light from the explosion would travel outward from the sun at the speed of light, just like all the other light from the sun.

 Post Extras:
gdd
Pooh-Bah

Reged: 11/23/05

Loc: N Seattle suburb, WA
Re: What would the sun appear if it exploded? [Re: AustinAstronomer]
#6478125 - 04/20/14 09:45 PM

You mean how far out would you have to be to watch the explosion progress without vaporizing from the intense light? Pluto? Out in the Oort cloud? Nearest star?

Gale

 Post Extras:
GlennLeDrew
Postmaster

Reged: 06/18/08

Re: What would the sun appear if it exploded? [Re: gdd]
#6478266 - 04/20/14 11:34 PM

The only difference in appearance would be angular scale (apparent size, which scales inversely with distance) and brightness (which scales inversely as the square of the distance.) In other words, like any object or event as view distance varies.

Tbe light travel time has no bearing; from the observer's point of view all events occur only as they are observed. The arrival of the photons and the gravitational effects (gravity waves) attending the event arrive/occur in step.

 Post Extras:
TCW
Pooh-Bah

Reged: 11/05/13

Loc: The North 40
Re: What would the sun appear if it exploded? [Re: chrisg]
#6478271 - 04/20/14 11:39 PM

It would depend if it were a super nova or "just" a nova. Either way you die before your brain could process what was happening unless you were on the night side of the earth and that might only buy you seconds at best.

 Post Extras:
chrisg
sage

Reged: 02/15/09

Re: What would the sun appear if it exploded? [Re: TCW]
#6478354 - 04/21/14 01:06 AM

Apologies about the grammatical error of my original question, I just edited it!

Maybe I'm too dense to see that my question was answered but here is my issue:

Say we're looking at the sun one day, but we don't realize that 8 minutes ago, the sun has started to explode. I'm assuming the sun's expansion is moving much more slowly than the speed of light. 8 minutes later, we can see that the sun has started to explode, all the while the sun's surface has been traveling towards us for those 8 minutes and is now closer to us than it was at the beginning.

At this point, the surface is say, 4 light minutes away. At some, eh, moment, the surface and light will be close enough to the earth that they'll arrive at the same time, and be in sync with each other. My question is, would the sun appear to explode faster or slower than it actually did? Would it start fast, then slow down? I just can't seem to wrap my head around how this would actually appear on this awful but perhaps beautiful moment in time.
Also, what filter should I use? Which eyepiece, Ethos or Delos?

Edited by chrisg (04/22/14 12:13 AM)

 Post Extras:
Dodge2013
super member

Reged: 01/05/14

Loc: Jackson, Tennessee
Re: What would the sun appear if it exploded? [Re: chrisg]
#6478374 - 04/21/14 01:19 AM

Sounds to me like someone is at work or it has been cloudy for days.

 Post Extras:
Midnight Dan
Postmaster

Reged: 01/23/08

Loc: Hilton, NY, Yellow Zone (Bortl...
Re: What would the sun appear if it exploded? [Re: chrisg]
#6478557 - 04/21/14 07:57 AM

Quote:

Apologies about the grammatical error of my original question, I just edited it!
Maybe I'm too dense to see that my question was answered already but here is my issue:
Say we're looking at the sun one day, but we don't realize that 8 minutes ago, the sun has started to explode. I'm assuming the sun's expansion is moving much slower than the speed of light. 8 minutes later, we can see that the sun has started to explode, all the while the sun's surface has been travelling towards us for those 8 minutes and is now closer to us than it was at the beginning. Now, the surface is say, 4 light minutes away. At some, eh, moment, the surface and light will be close enough to us that they'll be in sync with each other. My question is, would the sun appear to explode faster or slower than it actually did? Would it start fast, then slow down? I just can't seem to wrap my head around how this would actually appear on this awful but perhaps beautiful moment in time.
Also, what filter should I use? Which eyepiece, Ethos or Delos?

There would be no speeding up or slowing down. It would be linear. And clearly, it would appear to occur faster than actual.

Take an example. Let's say the surface of the sun explodes outward at 1/2 the speed of light for ease of calculation. The initial light would take 8 minutes to get here, while the surface would take 16 minutes ... eight minutes behind the initial light. So the event would appear to take 8 minutes, even though the surface required 16 minutes to arrive.

-Dan

 Post Extras:
ianfromoz
professor emeritus

Reged: 12/21/13

Re: What would the sun appear if it exploded? [Re: Midnight Dan]
#6478562 - 04/21/14 08:06 AM

If you live long enough you will see for yourself :-)

 Post Extras:
GlennLeDrew
Postmaster

Reged: 06/18/08

Re: What would the sun appear if it exploded? [Re: ianfromoz]
#6478758 - 04/21/14 10:13 AM

Even supernova ejecta do not much exceed 4,000 km/s. Compared to the 300,000 km/s for light, this is a speed ratio of about 8,000. The material is essentially at a standstill.

 Post Extras:
mrchunks
member

Reged: 03/23/14

Re: What would the sun appear if it exploded? [Re: Midnight Dan]
#6478940 - 04/21/14 11:48 AM

I respectfully disagree. Light is constant leaving the object at the speed of light not speeding up to it. Although its true the actual physical part of the surface would reach earth 16 min later the visual part would be in real time as we see the surface as it was 8 mm in ago not as it is. But we would be dead before the physical part reached us..

 Post Extras:
csrlice12
Postmaster

Reged: 05/22/12

Loc: Denver, CO
Re: What would the sun appear if it exploded? [Re: mrchunks]
#6479196 - 04/21/14 01:56 PM

A very bright, hot flash....you'd be dead before you knew it.....

 Post Extras:
sickfish
super member

Reged: 01/13/09

Loc: Watertown Ma.
Re: What would the sun appear if it exploded? [Re: csrlice12]
#6479205 - 04/21/14 01:58 PM

I dont think you would see anything. You are dead.

 Post Extras:
csrlice12
Postmaster

Reged: 05/22/12

Loc: Denver, CO
Re: What would the sun appear if it exploded? [Re: sickfish]
#6479226 - 04/21/14 02:07 PM

Hey all, I'm a Zombie!

 Post Extras:
howard929
Member

Reged: 01/02/11

Loc: Low End of High Ground
Re: What would the sun appear if it exploded? [Re: chrisg]
#6479228 - 04/21/14 02:09 PM

Realizing that light travels at speed C regardless of the benchmark of the observer, no filter would be required but a Delos for sure.

 Post Extras:
TCW
Pooh-Bah

Reged: 11/05/13

Loc: The North 40
Re: What would the sun appear if it exploded? [Re: chrisg]
#6479296 - 04/21/14 02:45 PM

As Sarah Conner said - anyone not wearing two million sunblock is going to have a really bad day.

The shockwave would arrive after the radiation blast but when the temperature goes up several million degrees in a nanosecond you won't be wondering what eyepeice is best.

 Post Extras:
howard929
Member

Reged: 01/02/11

Loc: Low End of High Ground
Re: How would the sun appear if it exploded? [Re: chrisg]
#6479315 - 04/21/14 02:59 PM

Possibly this helps some-what. Anyone outside in view of daylight sees that light from the Sun as it left the Sun X light minutes ago. The Sun explodes in what would likely be a blinding all encompassing to Earth flash of light. Since we are seeing what was, not what is, heat/light from such a blast would arrive that same X number of light minutes later but I seriously doubt that it's possible for eye to brain realization of such an event prior to vaporizing.

 Post Extras:
csrlice12
Postmaster

Reged: 05/22/12

Loc: Denver, CO
Re: How would the sun appear if it exploded? [Re: howard929]
#6479428 - 04/21/14 03:56 PM

Think of how cheap solar scopes would become....

 Post Extras:
Midnight Dan
Postmaster

Reged: 01/23/08

Loc: Hilton, NY, Yellow Zone (Bortl...
Re: What would the sun appear if it exploded? [Re: mrchunks]
#6479443 - 04/21/14 04:04 PM

Quote:

I respectfully disagree. Light is constant leaving the object at the speed of light not speeding up to it. Although its true the actual physical part of the surface would reach earth 16 min later the visual part would be in real time as we see the surface as it was 8 mm in ago not as it is. But we would be dead before the physical part reached us..

Hi MrChunks:

Not sure what you're referring to here. I didn't make any comments regarding the speed of light speeding up.

But just to clarify though, here is the timeline

1:00 pm on Earth
- Sun begins to explode. No visible sign of it on earth.

1:08 pm on Earth
- Light from sun's initial explosion reaches Earth. We see sun's surface beginning to move outward
- Actual surface of sun is now 1/2 way to Earth (based on fictitious example of surface moving at 1/2 light speed)

1:12 pm on Earth
- Light from sun's 1/2-way explosion point reaches Earth, after 4 minutes of travel
- Actual surface of sun is now 3/4 of the way to Earth

1:16 pm on Earth
- Sun's surface reaches Earth
- When sun's surface reaches Earth, light from the surface now arrives at the same time because it's right here.

So, if you look at the time line, the sun's surface took from 1:00pm to 1:16pm to get here - 16 minutes. But the first time we could observe it started at 1:08pm. Therefore the visible explosion took from 1:08pm to 1:16pm, or just 8 minutes.

I believe the OP is interested in this thought experiment, not whether we'd live or die or at what point our retinas burn out, so of course I'm ignoring all that.

-Dan

 Post Extras:
chrisg
sage

Reged: 02/15/09

Re: What would the sun appear if it exploded? [Re: Midnight Dan]
#6479530 - 04/21/14 04:55 PM

Exactly! Since the sun's light and surface are moving towards us at different speeds, but will eventually be in sync, then I'm assuming that the sun will appear to expand more quickly than it actually did. But, as the surface of the sun gets closer to earth, the expansion will appear to slow to it's actual rate.
I'm definitely no expert on the lives of stars but LeDrew has it right, the surface would probably be moving much more slowly, a quick look at Wikipedia/internet, seems like the sun should take around two hours to engulf the earth.
Either way, I'm intrigued with the idea that the appearance an event like this could be distorted by distance effects. Though please chime in if the logic is wrong!
My vote would be a pair of 20mm ethos in a binoscope. Isn't that what you have Glenn?

 Post Extras:
kfiscus
Carpal Tunnel

Reged: 07/09/12

Loc: Albert Lea, MN, USA
Re: What would the sun appear if it exploded? [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.

 Post Extras:
GlennLeDrew
Postmaster

Reged: 06/18/08

Re: What would the sun appear if it exploded? [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.

 Post Extras:
gdd
Pooh-Bah

Reged: 11/23/05

Loc: N Seattle suburb, WA
Re: What would the sun appear if it exploded? [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

 Post Extras:
Achernar
Postmaster

Reged: 02/25/06

Loc: Mobile, Alabama, USA
Re: How would the sun appear if it exploded? [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

 Post Extras:
Noisykids
sage

Reged: 06/01/11

Loc: ma
Re: How would the sun appear if it exploded? [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.

 Post Extras:
Mike B
Starstruck

Reged: 04/06/05

Loc: shake, rattle, & roll, CA
Re: How would the sun appear if it exploded? [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.

 Post Extras:
Midnight Dan
Postmaster

Reged: 01/23/08

Loc: Hilton, NY, Yellow Zone (Bortl...
Re: How would the sun appear if it exploded? [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

 Post Extras:
gdd
Pooh-Bah

Reged: 11/23/05

Loc: N Seattle suburb, WA
Re: How would the sun appear if it exploded? [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

 Post Extras:
mrchunks
member

Reged: 03/23/14

Re: What would the sun appear if it exploded? [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 ????

 Post Extras:
palmer570
super member

Reged: 09/04/12

Loc: Scranton, Pennsylvania
Re: What would the sun appear if it exploded? [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.

 Post Extras:
Mike B
Starstruck

Reged: 04/06/05

Loc: shake, rattle, & roll, CA
Re: What would the sun appear if it exploded? [Re: mrchunks]
#6479996 - 04/21/14 09:20 PM

Quote:

Yeah, supernova's will do that...

 Post Extras:
Mentor
professor emeritus

Reged: 09/30/10

Re: What would the sun appear if it exploded? [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.

 Post Extras:
Midnight Dan
Postmaster

Reged: 01/23/08

Loc: Hilton, NY, Yellow Zone (Bortl...
Re: What would the sun appear if it exploded? [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

 Post Extras:
chrisg
sage

Reged: 02/15/09

Re: What would the sun appear if it exploded? [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)

 Post Extras:
penguinx64
Pooh-Bah

Reged: 11/12/13

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

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

 Post Extras:
darren38
member

Reged: 04/02/14

Loc: Burlington, Vermont
Re: What would the sun appear if it exploded? [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.

 Post Extras:
darren38
member

Reged: 04/02/14

Loc: Burlington, Vermont
Re: What would the sun appear if it exploded? [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

 Post Extras:
Mentor
professor emeritus

Reged: 09/30/10

Re: What would the sun appear if it exploded? [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.

 Post Extras:
swix
member

Reged: 03/25/12

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

Say a quick goodbye...

 Post Extras:
csrlice12
Postmaster

Reged: 05/22/12

Loc: Denver, CO
Re: What would the sun appear if it exploded? [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.

 Post Extras:
rnc39560
Pooh-Bah

Reged: 07/23/13

Loc: MS coast
Re: What would the sun appear if it exploded? [Re: csrlice12]
#6480982 - 04/22/14 11:14 AM

 Post Extras:
Paco_Grande
Carpal Tunnel

Reged: 07/14/12

Loc: Banana Republic of California
Re: What would the sun appear if it exploded? [Re: csrlice12]
#6481042 - 04/22/14 11:45 AM

I have \$100 that says a bunch of cockroaches will survive.

Everything else? Buh bye.

 Post Extras:
TCW
Pooh-Bah

Reged: 11/05/13

Loc: The North 40
Re: What would the sun appear if it exploded? [Re: Midnight Dan]
#6481695 - 04/22/14 05:26 PM

Dan what you are missing is the radiation blast just like that of an atomic bomb arrives at the speed of light. You won't be around to see the shockwave arriving. I seriously doubt your brain could process anything in the time the temperature at your location goes from 75 degrees to 2,000,075 in a nanosecond.

To those who say the suns surface would arrive in 16 minutes that means the material would be traveling at 50% of the speed of light. I don't think that is possible.

 Post Extras:
Achernar
Postmaster

Reged: 02/25/06

Loc: Mobile, Alabama, USA
Re: How would the sun appear if it exploded? [Re: gdd]
#6481780 - 04/22/14 06:21 PM

For a supernova, that is one that is not the result of a gamma ray burst, you would have to be at least 30 light years away to be out the danger zone. The most massive nova outbursts would be no immediate threat beyond the star system in which they take place, but in either case you would not want to be in deep space outside of a planet's magnetosphere. Charged particles will be coming at nearly the speed of light, and they can be lethal to both electronics and living cells. A planet's magnetic field can block them from ever reaching the planet's atmosphere and surface.

Taras

 Post Extras:
Midnight Dan
Postmaster

Reged: 01/23/08

Loc: Hilton, NY, Yellow Zone (Bortl...
Re: What would the sun appear if it exploded? [Re: TCW]
#6490583 - 04/26/14 07:42 PM

Quote:

Dan what you are missing is the radiation blast just like that of an atomic bomb arrives at the speed of light. You won't be around to see the shockwave arriving. I seriously doubt your brain could process anything in the time the temperature at your location goes from 75 degrees to 2,000,075 in a nanosecond.

To those who say the suns surface would arrive in 16 minutes that means the material would be traveling at 50% of the speed of light. I don't think that is possible.

No one said the sun's surface would arrive in 16 minutes or that it would travel at half the speed of light. If you read the thread you'll see that it's a fictitious example provided for ease of calculation. Its just for illustrative purposes.

-Dan

 Post Extras:
DTH
super member

Reged: 08/11/13

Loc: Georgia
Re: What would the sun appear if it exploded? [Re: Midnight Dan]
#6490635 - 04/26/14 08:10 PM

I'd be to busy with my head between my legs while escaping earth aboard the Millennium Falcon to take a look at the explosion. But as far as filters--use a variable polarizing filter--it won't really matter--you'll be blind.

 Post Extras:
maugi88
Carpal Tunnel

Reged: 08/25/13

Loc: SE MN
Re: What would the sun appear if it exploded? [Re: DTH]
#6490925 - 04/26/14 10:27 PM

Clearly, the sun would have already engulfed the planet earth BEFORE it exploded. So we would not be here to see it.

The sun will expand to beyond the orbit of Mars and then implode to become a white dwarf. The Earth will be vaporized. So we will never see the sun explode. In Billions of years that is.

Edited by maugi88 (04/26/14 10:33 PM)

 Post Extras:
sslcm56
super member

Reged: 07/20/12

Loc: Montgomery, Al.
Re: What would the sun appear if it exploded? [Re: maugi88]
#6491144 - 04/27/14 01:43 AM

Oh my gosh....Who the *bleep* cares? The light gets bright and you are in the presence of God. Good luck then.:)

Edited by sslcm56 (04/27/14 01:45 AM)

 Post Extras:
TCW
Pooh-Bah

Reged: 11/05/13

Loc: The North 40
Re: What would the sun appear if it exploded? [Re: Midnight Dan]
#6491157 - 04/27/14 02:06 AM

 Post Extras:
17.5Dob
sage

Reged: 03/21/13

Just to play along [Re: chrisg]
#6491162 - 04/27/14 02:10 AM

If there is any hope for Homo Sapiens, and it's further evolved decedents, if they even survive, barring asteroid strikes, mutant virus, over population, nuclear/chemical/biological wars etc. to witness the Sun explode, they will have to invent the the technology to move out of our entire solar system.

Long before the sun goes nova, it will have bloated up/ swallowed up/vaporized the the entire planet formerly known as "Earth" .

People are arguing about "Human Caused Global Warming" and being able to mitigate the effects already. Is it really "Human Caused" or just the next evolutionary phase of our planet as a whole ?

In any event, the Earth will have roasted to vapor, long before the Sun explodes.

How many light years beyond our current world can we move to witness the sun explode, and report about it, remains to be seen.

 Post Extras:
mayidunk

Reged: 02/17/10

Loc: Betwixt & Between...
Re: How would the sun appear if it exploded? [Re: chrisg]
#6491168 - 04/27/14 02:17 AM

It would likely appear to be just a teensy bit brighter... But only for a split second before you, I, and the rest of the world were instantly incinerated!

Edited by mayidunk (04/28/14 12:29 AM)

 Post Extras:
SpooPoker
sage

Reged: 06/04/13

Loc: North Bay CA
Re: How would the sun appear if it exploded? [Re: mayidunk]
#6491212 - 04/27/14 02:53 AM

I am no astrophysicist but seem to recall that there is a limit, perhaps 8 times the mass of the sun as being the minimum mass for a star to go supernova, i.e. explode. Below this limit, the star essentially gets larger, more tenuous, cooler (in the red spectrum, i.e. red giant), and eventually shedding its tenuous outer layers going straight to white dwarf stage without going kablooey. Stars like our sun become red giants and then white dwarfs as part of their evolution - they run out of fuel so to speak and the forces of gravity that keep the star intact no longer can counterbalance the coulomb forces pushing outward from the core.

The sun is a small star, very small in fact. In a statistical analysis, it would be well above average given the huge population of red and brown dwarfs, but in reality, out sun is a little tiddler. No explosion or cosmic fireworks. However, Betelgeuse, approx 50ly away, is a supernova waiting to happen. It is too far away for thermal radiation to incinerate life on Earth but apparently it could radiate enough UV/X/Gamma Rays to interfere with the Ozone layer. In the visible spectrum it would be bright enough to outshine the Moon - it would certainly be a spectacular sight.

 Post Extras:
mseto
member

Reged: 08/27/13

Loc: Cincinnati
Re: How would the sun appear if it exploded? [Re: SpooPoker]
#6494219 - 04/28/14 04:20 PM

Larry Niven wrote a short story on this topic called Inconstant Moon. Great story, won a Hugo. Starts off with a guy noticing the moon starting to get really bright...

 Post Extras:
Qwickdraw
Carpal Tunnel

Reged: 03/03/12

Loc: Ann Arbor, MI
Re: How would the sun appear if it exploded? [Re: Achernar]
#6494262 - 04/28/14 04:46 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 Taras said

 Post Extras:
Thudley
journeyman

Reged: 04/27/14

Loc: East Bay SFO, CA
Re: How would the sun appear if it exploded? [Re: Qwickdraw]
#6494703 - 04/28/14 08:51 PM

I had a question related to this from a 7th grader. We were covering the speed of light, and I mentioned that we see the Sun as it was about 8 minutes ago. I casually mentioned that the Sun may have exploded a few minutes ago, but we won't see that for another few minutes. One student asked, "If the Sun exploded, would it's gravity change also take 8 minutes to affect the Earth?"

That's what we call, "stump the dummy".

 Post Extras:
ChristianG
sage

Reged: 10/18/12

Re: How would the sun appear if it exploded? [Re: Thudley]
#6494863 - 04/28/14 10:19 PM

Hi. Good question. Because the answer is not simple.

Gravity waves (and any other disturbances in gravity) also should travel at the speed of light. I say should because we are still trying to observ them. Lots of stuff to read there at the LIGO site.

Other point, however, is that an explosion would be spherically symmetrical and until the stuff hits the Earth, the total mass (minus a bit from energy conversion) would be the same and the position of the center of mass of the Sun would not change. So gravity from the Sun would not change until the exploding stuff (mostly helium I suppose??) would reach the Earth orbit. Then gravity would start to decrease as more stuff would end up past the Earth orbit (what's left of it anyway).

--Christian

 Post Extras:
Thudley
journeyman

Reged: 04/27/14

Loc: East Bay SFO, CA
Re: How would the sun appear if it exploded? [Re: ChristianG]
#6495853 - 04/29/14 01:22 PM

That's what I finally came up with for my answer. As long as all the matter is still inside the Earth's orbit, the gravity field is still there. Just an educated guess on my part at the time.

 Post Extras:
csrlice12
Postmaster

Reged: 05/22/12

Loc: Denver, CO
Re: How would the sun appear if it exploded? [Re: Thudley]
#6495910 - 04/29/14 01:43 PM

"It was as if the lifeforce of billions of people just dissappeared"....or something similar to that....Obiwan Kenobe

 Post Extras:
Valorum
member

Reged: 02/28/14

Loc: NW GA
Re: How would the sun appear if it exploded? [Re: Thudley]
#6495915 - 04/29/14 01:46 PM

I heart this discussion

 Post Extras:
ChristianG
sage

Reged: 10/18/12

Re: How would the sun appear if it exploded? [Re: Thudley]
#6496325 - 04/29/14 05:12 PM

Quote:

As long as all the matter is still inside the Earth's orbit, the gravity field is still there. Just an educated guess on my part at the time.

FYI, Gauss' theorem in electricity (if that rings a bell, otherwise ignore) applies to gravity as well. So your educated guess was rather accurate!

--Christian

 Post Extras:
Skokauckas
member

Reged: 06/13/10

Loc: Arizona -United States
Re: How would the sun appear if it exploded? [Re: ChristianG]
#6497506 - 04/30/14 06:49 AM

Well, if the Sun decided to go BOOM at least we all could say that we were a part of a Great Astronomical Event...

Clear Skies!

 Post Extras:
Pages: 1 | 2 | 3 | 4 | (show all)

Extra information
20 registered and 31 anonymous users are browsing this forum.

Moderator:  WOBentley, kkokkolis

Forum Permissions
You cannot start new topics