Slashdot Mirror
Star Falls Into Black Hole
thodelu writes with news that astronomers recently got a look at what they believe is a star falling into a black hole. Phil Plait explains:
"As the star approached this bottomless pit, the side of the star facing the black hole was pulled far harder than the other side of the star, which may have been a million or more kilometers farther away from the black hole. This change in pull stretched the star — this stretching is called a 'tide,' and is essentially the same thing that causes tides on the Earth from the Moon’s gravity and when the star wandered too close to the black hole, the strength of that pull became irresistible, overcoming the star’s own internal gravity. In a flash, the star was torn apart, and octillions of tons of ionized gas burst outward! This material whipped around the black hole, forming a disk of plasma called an accretion disk. Magnetic fields, friction, and turbulence superheated the plasma, and also focused twin beams of matter and energy which blasted out from the poles of the disk, away from the black hole itself. The energy stored in these beams is incredible, crushing our imagination into dust: for a time, they shone with the light of a trillion Suns!"
Why is Slashdot covering Charlie Sheen now?
I would be quite surprised if one was able to witness the entire event through a telescope from start to finish. I'm curious how long it takes a star to "fall into a black hole" from start to finish.
Rhymes that keep their secrets will unfold behind the clouds.There upon the rainbow is the answer to a neverending story
Is a distortion of both Time and Space.
While a star being stretched and pulled into a Black Hole, and perhaps giving out a death cry (rather poetically written as: "The energy stored in these beams is incredible, crushing our imagination into dust: for a time, they shone with the light of a trillion Suns!") is certainly fascinating stuff. It seems to me that within its own reality the Sun remains unstreched, unbent and happy as can be until it merges with that which is the black hole (which itself is converting matter to energy, emitted from its poles.)
A feeling of having made the same mistake before: Deja Foobar
That's OVER 9000 times the force of 1000 suns!
"When information is power, privacy is freedom" - Jah-Wren Ryel
You lose, Sentry! Trillion suns beats a million!
Is this a rhetorical phrase like ginormous, or is this number actually defined somewhere?
An Octillion is 1,000 Septillions.
A Septillion is 1,000 Augustillions.
An Augustillion is 1,000 Julytillions.
A Julytillion is 1,000 Junetillions.
A Junetillion is 1,000 Maytillions.
A Maytillion is 1,000 Apriltillions.
An Apriltillion is 1,000 Marchtillions.
And a Marchtillion is 1,074 Februarytillions (except every 4 years when it's exactly 1,000 Februarytillions.)
Next time look it up in Googol.
A feeling of having made the same mistake before: Deja Foobar
Any site that "embiggens" images when you click on them is OK with me.
Sorry, but gray text on gray background is making my eyes bleed.
NO, absolutely not. An outside observer sees time "slow down" for objects that are approaching a black hole, so that each falling object approaches the event horizon asymptotically BUT NEVER ACTUALLY REACHES IT.
If you watched somebody falling into a black hole, and you kept a telescope trained on his wristwatch, you would see the second hand sweep slower and slower as he got closer to the EH distance. No matter how long your wait, you'll never actually see anything cross the EH from the outside.
(I am not kidding, this is what actually would happen. If this seems unpossible, don't worry too much--unless you've already studied special relativity and grasped at least that much, this is pretty counter-intuitive.)
If I took a cube 100 meters on a side, carved information on it that could be read from a distance, and slung it past the EH
You euthanized your faithful Companion Cube more quickly than any test subject on record. Congratulations.
I don't care if it's 90,000 hectares. That lake was not my doing.
No matter how long your wait, you'll never actually see anything cross the EH from the outside.
Not to burst your bubble or anything, but if nothing ever appears to cross the Event Horizon from an outside perspective then everything that has ever fell in would still look as though it hadn't. All the fallen objects would appear to be continuing to circle the black hole just like everything else in the universe appears to be doing. This could quite possibly, if not probably, mean we have all already passed the Event Horizon of a black hole and are on the inside looking out, rather than the outside looking in.
Personally, methinks the math needs a little more work if you calculate an object traveling a minute distance pulled by incredible force would take an infinite amount of time.
If you want to understand the tidal gradient around a very dense object, go read Larry Niven's Neutron Star.
/. is slipping.
And you shouldn't have had to scan down 123 postings to find this.
"It's the height of ridiculousness to say for those 9 lines you get hundreds of millions."
No he wouldn't. He looks back and sees the stationary guy 1000km away, but the light took a certain amount of time to get to him, negating any possibility of seeing the "future". The further out into the universe he looks, the further back in time he looks -- the same as happens to us when we stare really far into the sky from Earth -- if we're looking at something 1000 light years away, we know that it happened 1000 years ago (or more, if something managed to slow down the light for part of the journey). We can NEVER see the future (or for that matter, the present). Even reading this on your screen is old news by a tiny fraction of a second as the light moves from your screen to your eye.
Basically from the moving observer's perspective, nothing unusual is happening at all until the tidal forces kick in.
As he gets closer and closer to the singularity the tidal forces would rip him into atoms, then the atoms get ripped apart layer by layer until you end up with individual quarks (and who knows what it means to rip a quark or an electron apart.. ie: what happens when space is so warped that a signal can't make it from one side of a quark to the other without exceeding c.)
All that said, the stationary observer would NOT see the moving guy forever. As others have noted, along with seeing him slow down indefinitely, we'd also see him redshift indefinitely. Eventually he'd be so redshifted that he'd no longer be detectable by the instruments of the stationary observer. He'd still "be there" but could no longer be seen. A more sensitive instrument could see him for a longer period of time, but he'd still fade out eventually as all instruments no matter how good will have a finite cutoff for what they can detect.