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How Would an Astronaut Falling Into a Black Hole Die?

Soulskill posted 1 year,19 days | from the probably-heart-attack dept.

Space 412

ananyo writes "According to the accepted account, an astronaut falling into a black hole would be ripped apart, and his remnants crushed as they plunged into the black hole's infinitely dense core. Calculations by Joseph Polchinski, a string theorist at the Kavli Institute for Theoretical Physics in Santa Barbara, California, though, point to a different end: quantum effects turn the event horizon into a seething maelstrom of particles and anyone who fell in would hit a wall of fire and be burned to a crisp in an instant. There's one problem with the firewall theory. If Polchinski is right, then either general relativity or quantum mechanics is wrong and his work has triggered a mini-crisis in theoretical physics."

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412 comments

Somebody, quick! (-1)

Mexoplex (2736265) | 1 year,19 days | (#43370853)

This looks like a job for Dr. SHELDON COOPER!

Re: Somebody, quick! (5, Insightful)

Anonymous Coward | 1 year,19 days | (#43370915)

The /. I knew and loved a decade ago is gone.

Re: Somebody, quick! (2, Funny)

Anonymous Coward | 1 year,19 days | (#43371151)

The /. we all knew and loved a decade ago was gone by 1997.

Re: Somebody, quick! (1)

Entropius (188861) | 1 year,19 days | (#43371287)

That's more than a decade ago. But, in the Slashdot of yore, nobody could do math, so it's all good.

Re: Somebody, quick! (4, Funny)

Jeremiah Cornelius (137) | 1 year,19 days | (#43371355)

How would he die?

Of old age, on the multimillion year journey to the nearest black hole, I suppose.

But don't let me be the one to interrupt your little rec time, on the holodeck. ;-)

Re:Somebody, quick! (0, Flamebait)

Anonymous Coward | 1 year,19 days | (#43371083)

Leave your crappy sitcom references at the door and let the adults talk.
 
Take the time to read too, you might learn something that isn't some comic book fantasy.

Re:Somebody, quick! (0)

Anonymous Coward | 1 year,19 days | (#43371209)

Leave your crappy sitcom references at the door and let the adults talk. Take the time to read too, you might learn something that isn't some comic book fantasy.

Adults don't talk like that. Insecure teenagers trying clumsily to mimic adults do.

Re:Somebody, quick! (4, Funny)

hawguy (1600213) | 1 year,19 days | (#43371281)

Leave your crappy sitcom references at the door and let the adults talk.

Take the time to read too, you might learn something that isn't some comic book fantasy.

Besides, if anyone knows the answer, it's Dr. Hans Reinhardt.

Re:Somebody, quick! (0)

Anonymous Coward | 1 year,19 days | (#43371449)

Please shoot yourself.

Gravitational tides will kill you (1)

Anonymous Coward | 1 year,19 days | (#43370859)

long before the astronaut gets to the event horizon. Both can be correct.

Re:Gravitational tides will kill you (5, Informative)

Anonymous Coward | 1 year,19 days | (#43371107)

Heck, considering what we know about the environments around black holes, not only will the gravitational tides kill you before you reach the event horizon, so will the radiation.

Everybody repeat after me: "Black holes ain't yer friend. Don't try to hug them, you will die."

Re:Gravitational tides will kill you (5, Funny)

Sarten-X (1102295) | 1 year,19 days | (#43371421)

Heck, considering what we know about the locations of black holes and the speed of manmade spacefcraft, old age will probably kill you before you get close enough to notice the gravity.

Everybody repeat after me: "Space is big. Don't mind Sarten-X, he is a jackass."

Re:Gravitational tides will kill you (5, Funny)

Anonymous Coward | 1 year,19 days | (#43371363)

If the astronaut gets across the event horizon, then he will never die relative to us. So, there really isn't a problem here as far as I can tell.

Re:Gravitational tides will kill you (2)

rwa2 (4391) | 1 year,18 days | (#43371473)

Yeah, that sounds about right. The last time I read about this... somewhere... it really depended upon the size of the black hole.

Approaching a small black hole, the gradient in gravitational forces closer to the black hole means that e.g. diving head-first into a black hole would mean your head would feel a stronger gravitational pull than your feet and thus your body would be stretched and ripped apart.

Approaching a much more massive black hole with a larger event horizon could reduce that gravitation gradient enough. But of course you'll be much further from the singularity point as well.

Of course, both ignore the particle soup of other things falling into black holes that would surround most actual black holes.... which is what this article is considering. As well as the fact that it's pretty difficult to dive directly into a celestial object vs. falling into it via a gradually decaying orbit (which is what most of the particle soup is doing).

Also, someone say something about frame dragging effects near such large relativistically-moving amounts of mass.

We must find out for sure! (5, Funny)

Kenja (541830) | 1 year,19 days | (#43370869)

Locate a black hole and start shooting monkeys at it! "Science can not progress without heaps [of monkeys]"

Re:We must find out for sure! (0)

lgw (121541) | 1 year,19 days | (#43370935)

I do endorse experimental approaches!

However, for a big black hole I'd expect the monkeys to survive - how embarrassing! We think of the event horizon as an extreme environment because that's true of star-sized black holes, but with enough mass, the gravity at the event horizon is only 1 g, and I can't think of anything that would kill you as you passed that point.

IIRC "1 g at the event horizon" was 100 million solar masses, but my memory could be way off. Anyone know for sure?

Re:We must find out for sure! (4, Informative)

HappyHead (11389) | 1 year,19 days | (#43371171)

One problem that I see with that, is that the event horizon is defined as the place where gravity is so strong that light can't escape - light can easily escape from 1g, so that's not the event horizon.

I suspect that you're confusing gravity with density - as the black hole's event horizon gets bigger, the density gets lower. I can't remember exactly, but if the event horizon is somewhere around the radius of our solar system, you get an average density around the same as our atmosphere. The gravity's still a heck of a lot higher than 1g at the event horizon though.

Re:We must find out for sure! (3, Interesting)

lgw (121541) | 1 year,19 days | (#43371335)

light can easily escape from 1g

Turns out it can't. Surprising, isn't it? The magnitude of gravity at the event horizon isn't why light can't escape - it's the fact that space itself is effectively rushing into the black hole. There aren't really any good intuitions to be had about conditions at the event horizon.

I'm not good enough to explain it well, but I think of it as the "time" direction points towards the singularity at the event horizon. No matter how good your engines are, you can't apply that thrust in a direction useful for escape.

Re:We must find out for sure! (3, Interesting)

lgw (121541) | 1 year,19 days | (#43371231)

Hmm, working this out for myself:

The radius of the event horizon is:

R = 2GM/c^2

a = GM/R^2 = c^4/(4GM)

The units are right, so I think that's right. Setting a = g we get

M = c^4 / 4Gg ~= 3 * 10^42 kg ~= 1.5 * 10^12 solar masses

So, yeah, I was way off.

Still, a trillion-solar-mass black hole could possibly exist in the universe to lob monkeys at, I'm betting on the monkeys surviving the event horizon passage for a while.

Re:We must find out for sure! (1)

gewalker (57809) | 1 year,19 days | (#43371277)

If the gravity at the "event horizon" were 1g, certainly light at the event horizon could go well outside the event horizon (but not to infinity) before the gravity curved it back into the well. If I had a rocket just inside that event horizon, I should be about to fly out of the black hole as well -- my exhaust would all be trapped, but I could move the part of the total ship mass containing me outside of the event horizon by sacrificing the momentum of the exhaust.

An observer at infinity would see the rocket disappear when it dropped below the event horizon, but then reappear after it returned outside the event horizon.

If not, why not?

Re:We must find out for sure! (4, Interesting)

lgw (121541) | 1 year,18 days | (#43371479)

No matter the size of a black hole, gravity at the event horizon is finite. You could always in theory build rockets more powerful than whatever it is. It won't help you.

Newtonian acceleration determines how much gravity you feel, but not how you actually move, near a black hole, because space itself is effectively rushing across the event horizon.

I'm not good enough at this to explain it well, but as I replied to a sibling post, I think of it as if the time axis has rotated to point towards the singularity. As I understand it, the event horizon is where the time axis points at 45 degrees off the center, and no matter how hard you accelerate, you can't quite change your own vector more than 45 degrees off the time axis, so you're stuck.

Maybe we'll get a physics prof to wander past and explain this better!

Re:We must find out for sure! (3, Insightful)

Hentes (2461350) | 1 year,19 days | (#43370965)

The problem is that we won't be able to observe what happens to them inside the event horizon. If you want to be sure, you have to go yourself.

Re:We must find out for sure! (1)

David_Hart (1184661) | 1 year,19 days | (#43371427)

Locate a black hole and start shooting monkeys at it! "Science can not progress without heaps [of monkeys]"

Isn't this how Planet of the Apes got started.... just saying... I, for one, welcome our new black hole traveling monkey overlords...

Re:We must find out for sure! (3, Interesting)

TheLink (130905) | 1 year,18 days | (#43371471)

Blackholes might not be that uncommon.
http://physicsworld.com/cws/article/news/2013/mar/15/micro-black-holes-could-form-at-lower-than-expected-energies [physicsworld.com]
There are even some theories that some ball lightning could be due to blackholes:
http://en.wikipedia.org/wiki/Ball_lightning#Black_hole_hypothesis [wikipedia.org]

Imagine a tiny blackhole with literally tons of charged particles beyond the event horizon (which is not far away for a tiny blackhole) in close very high speed orbit around it. Those particles might still be affected by magnetic fields, and how about their gravitational effect on the blackhole itself?

Perhaps some real physicists can explain what would happen in such a scenario.

Quantum mechanics and relativity (1)

yo303 (558777) | 1 year,19 days | (#43370873)

We already know that QM and relativity can't both be true. Each theory is very good at predicting things in its realm, but they are mutually exclusive.

Re:Quantum mechanics and relativity (5, Insightful)

Entropius (188861) | 1 year,19 days | (#43371329)

This isn't true.

QM and *special* relativity get along just fine. When you combine them in a simple way you get predictions like antimatter, the fine structure of the hydrogen atom, and so on. If you do this in a more detailed way, using quantum field theory, you get the fantastically accurate predictions of quantum electrodynamics, the theory of quantum chromodynamics that can't be solved with pen and paper but which still gives accurate predictions when done on supercomputers, and so forth.

And there's nothing forbidding QM from playing nice with general relativity, either; we just don't know how it works yet. There are some models, like lattice quantum gravity, that seem quite promising.

Spaghetti (1)

puddingebola (2036796) | 1 year,19 days | (#43370909)

You would be stretched out into Spaghetti!! I saw the movie! Stephen Hawking said so himself.

Re:Spaghetti (4, Funny)

PPH (736903) | 1 year,19 days | (#43371057)

.... becoming one with the FSM.

Re:Spaghetti (0)

Anonymous Coward | 1 year,19 days | (#43371347)

In Soviet black hole star, FSM = FRYING Spaghetti Monster!

Gravitational time dilation (1)

PPH (736903) | 1 year,19 days | (#43370919)

The astronaut dies of old age?

Re:Gravitational time dilation (2)

Motard (1553251) | 1 year,19 days | (#43371067)

Yes, because getting to a black hole will take a long time.

Re:Gravitational time dilation (1)

Kaptain Kruton (854928) | 1 year,19 days | (#43371161)

Yes, because getting to a black hole will take a long time.

Your description of time is to general and relative.

Re:Gravitational time dilation (0)

Anonymous Coward | 1 year,19 days | (#43371469)

Your description of time is to general and relative.

So is your grammar.

Re:Gravitational time dilation (0)

Anonymous Coward | 1 year,19 days | (#43371143)

Gravitational time dilation would be an affect observed by outsiders only.
For the individual entering the gravity well everything would proceed at "normal" speed even though it might appear to take millenia from the perspective of an observer.

Re:Gravitational time dilation (2, Insightful)

Anonymous Coward | 1 year,19 days | (#43371409)

You got that exactly backwards.

Refer to Stargate SG-1 episode "A Matter of Time" (Season 2 Episode 16): "SG-10 is stranded on planet P3W-451, which is close to a newly formed black hole. The SGC opens the gate to find out what happened, but they cannot shut it down afterwards. Soon they realize that since the planet is near to a black hole, its intense gravity is causing time dilation, so if they do not shut down the gate very soon, it will destroy the SGC, and in time, the entire planet."

People outside the base have much longer to think about what's happening inside the base. e.g. At one point Hammond spends 18 hours off base while those inside the base think he was only gone for ~20 minutes.

Re:Gravitational time dilation (4, Informative)

Culture20 (968837) | 1 year,19 days | (#43371183)

The other way around: The universe dies of old age around the astronaut and black hole.

Re:Gravitational time dilation (4, Interesting)

RoccamOccam (953524) | 1 year,19 days | (#43371373)

There was an SF short story in which an interstellar alien being was psychically-linked with a human and was helping her team study a black hole. The alien is unable to escape the gravity well and is quickly destroyed. Unfortunately, for the human, the alien's time frame is different, so the human will experience its psychic scream for her entire life.

Re:Gravitational time dilation (0)

Anonymous Coward | 1 year,19 days | (#43371437)

There's also a Stargate SG1 episode built around a blackhole. They're unable to disengage the gate, and the gravitational effects begin bleeding through to Earth.

Black hole argument (0)

Anonymous Coward | 1 year,19 days | (#43370937)

I thought that black holes were still theoretical. Or have they been scientifically proved, and I'm just an asshat?
If they're still theoretical, why would any assumption as to their mechanism "triggered a mini-crisis in theoretical physics"?

Myself, I theorize that when approaching a black hole, one experiences "the hole" as something that may get closer and closer, but you will move in a 'new way'. This is to say that if you are between stuff and the black hole, then the stuff further than you from the hole will appear to sped up greatly, and you will not. The closer that you get to 'the hole' the faster everything outside of the hole moves, and when you touch 'the hole' everything happens at the same time.

Oh shit, did someone just blow the theoretical werld?? no.

Re:Black hole argument (3, Informative)

Anonymous Coward | 1 year,19 days | (#43371197)

I thought that black holes were still theoretical. Or have they been scientifically proved, and I'm just an asshat?

They've been observed - just because there's theoretical work being done about something doesn't mean it hasn't been shown to exist.

Re:Black hole argument (0)

Anonymous Coward | 1 year,19 days | (#43371313)

and you are an asshat also.

Re:Black hole argument (0)

Anonymous Coward | 1 year,19 days | (#43371359)

Observations consistent with black holes have been observed but black holes themselves have not, for the obvious reason.

Re:Black hole argument (2)

Hatta (162192) | 1 year,19 days | (#43371395)

Yes, black holes have not only been observed, but super-massive black holes have been discovered at the center of every galaxy we've checked.

Re:Black hole argument (5, Informative)

meerling (1487879) | 1 year,19 days | (#43371443)

They've found numerous stellar objects of various sizes that conform to the preditions of black holes. (Mass, diameter, etc) Though none have been directly observed, their 'feeding' does generate a lot of energy that is detected when something falls in. Just recently one that had been relatively quiet for some time gave of a nice 'burp' of radiation as it apparently 'ate' a planet.

Have we been to a black hole? No.
Have we taken photos of an actual black hole? No.
Have we seen gravitational effects that look exactly like what a black hole should have? Yes.
Do those gravitational effects calculate out as something of several to millions of solar masses in a tiny volume that can't exist in any non-black hole way that we are aware of? Yes.
Have we seen the radiation from an accretion disk falling into and being destroyed by a black hole as predicted? Yes.
Is a black hole what astrophysicists think it is? Probably.
Is a black hole what non-scientists (hollywood, general public, dentists, etc) think it is? Probably not.
Do you really exist? This is about black holes, but your existence is only a bit less theoretical than that of a black holes, though some of the specifics of either may not be what is generally thought about them.

And no, a black hole is not god dividing by zero. It's more likely an alien mad scientist multiplying by the square root of negative zero. :D

They're all Wrong! (1)

Anonymous Coward | 1 year,19 days | (#43370951)

As my advisor would say, all models, all theories are wrong... the only question is: Are they useful?

Newton is wrong, but the models he developed for large body dynamics are still the foundation of a great deal of stuff. Pick your model from any field, chemistry, biology, physics, genetics, etc... they are all "wrong" ... they are all missing something, but as long as you know the limitations of the model you can still use it to design, predict and understand small pieces of the world.

Re:They're all Wrong! (0)

Anonymous Coward | 1 year,19 days | (#43371365)

Your advisor needs to brush up on their Box, as well as learning what constitutes a scientific theory.

Re:They're all Wrong! (1)

Entropius (188861) | 1 year,19 days | (#43371367)

This doesn't mean that they're wrong; it means that the region of their applicability is bounded. Dealing with such bounds wasn't done in any formal way in Newton's time, but now we have an entire field of study, of "effective field theories", that are a rigorous way to understand how a complicated model behaves in some limit or other. (The example I am most familiar with is "chiral perturbation theory", which consists of pretending the world is made of protons, neutrons, and pions at low energy, knowing full well that those guys are made of quarks once you squint hard enough but not caring. It turns out that chiral perturbation theory is very useful and powerful.)

There's science that refutes this, too. (0)

Anonymous Coward | 1 year,19 days | (#43370961)

http://www.sciencedaily.com/releases/2013/03/130306084151.htm

If most of the black hole's entropy comes from entanglement across the event horizon, then (according to these researchers) the firewall never descends and the black hole can evaporate in peace.

Both? (0)

Anonymous Coward | 1 year,19 days | (#43371013)

Why can't the correct answer be both? You are first burned to crisp. Then your ashes are crushed.

Re:Both? (0)

Anonymous Coward | 1 year,19 days | (#43371263)

Why can't the correct answer be both?

Because you can only die once, therefore you can only die in one way. Remember that the question is "how would you die", not "what would happen to your body".

You are first burned to crisp. Then your ashes are crushed.

Then the answer is "the astronaut would die by being burnt to a crisp". What happens to the ashes afterwards is beyond the scope of the question.

Bad headline (4, Insightful)

SirGarlon (845873) | 1 year,19 days | (#43371015)

TFA is an interesting article about a physicist apparently discovering an inherent contradiction between general relativity and quantum mechanics. The "black hole" stuff is really just the context that led to the apparent contradiction: the real issue is much deeper than that. It's depressing that the real underlying hypothesis isn't considered newsworthy, and the editor feels the need to lead with the "black hole" stuff.

Re:Bad headline (4, Interesting)

bluefoxlucid (723572) | 1 year,19 days | (#43371077)

Polchinski is actually correct, sort of. Everything approaching a black hole is being compressed; you'd be exposed to the burning energy of a hundred thousand million thermonuclear explosions before reaching the event horizon.

Re:Bad headline (1)

DerekLyons (302214) | 1 year,19 days | (#43371175)

That contradictions exist between Newtonian physics, relativity, and quantum mechanics is pretty much old news.

There is only one answer (0)

Anonymous Coward | 1 year,19 days | (#43371025)

How Would an Astronaut Falling Into a Black Hole Die?

Fast!

Re:There is only one answer (0)

Anonymous Coward | 1 year,19 days | (#43371267)

Only from his own perspective. To the rest of us, it would look like it was drawn out forever.

QM vs Relativity is not a new mini crisis. (0)

Anonymous Coward | 1 year,19 days | (#43371027)

The dissonance of QM and Relativity has been known for a long time, since the days of Einstein, Bohr, et al... It was not triggered by the new "firewall theory"

Re:QM vs Relativity is not a new mini crisis. (1)

TechyImmigrant (175943) | 1 year,19 days | (#43371163)

Right, but this finding gives theoreticians something they can get to grips with in a much more tangible way than the hand-wavey incompatibility of QM and GR.

no one escapes the Black Hole (2)

pezpunk (205653) | 1 year,19 days | (#43371063)

i agree the reversed lower playfield can be a bit disorienting at first, but let's not get melodramatic -- since there are no outlanes in the gravity well, a quick SDTM drain is really the only way to die down there, and completing either bank of drop targets opens the re-entry gate anyway.

How would he die? (0)

Anonymous Coward | 1 year,19 days | (#43371089)

How would he die? Why the black hole would kill him, that's how!

Why Waste an Astronaut? (1)

avandesande (143899) | 1 year,19 days | (#43371091)

Shouldn't we use a convicted murderer or something?

Re:Why Waste an Astronaut? (4, Funny)

pezpunk (205653) | 1 year,19 days | (#43371157)

well, technically, wouldn't the convicted murder BECOME an astronaut by definition the moment we shot him into space?

slashdot is really provoking the deep questions today.

Re:Why Waste an Astronaut? (1)

avandesande (143899) | 1 year,19 days | (#43371247)

not according to wikipedia: "An astronaut or cosmonaut is a person trained by a human spaceflight program to command, pilot, or serve as a crew member of a spacecraft."
I wouldn't waste resources training the person.

Re:Why Waste an Astronaut? (0)

Anonymous Coward | 1 year,19 days | (#43371225)

Good news! We just found a job for all those self-loathing literature PHDs.

Re:Why Waste an Astronaut? (1)

hawguy (1600213) | 1 year,19 days | (#43371447)

Shouldn't we use a convicted murderer or something?

I think there would be plenty of volunteers for a one-way trip to a black hole -- volunteers more willing to make scientific observations than a death-row inmate forced to go.

Besides, what if the inmate banished from earth finds himself released by an atomic shockwave from a planet that his prison-ship flies near and he goes to that planet and finds that he has superpowers granted by the planet's sun, and he wreaks havoc on that planet as a super-villan until someone on the planet with super-powers to match the criminal manages to stop him?

Painfully (1)

onyxruby (118189) | 1 year,19 days | (#43371099)

At this point all we have in conjecture as actually studying what would happen is for all intents and purposes impossible. Are you crushed, burned alive by everything else, toasted by radiation, spaghettified, or some other horrible fate?

The only thing that we /really/ know is that any possible fate you would have from falling into a black hole would be painful. Unless you are killed so quickly your body never has a chance to transmit the signals for excruciating pain. The bottom line is that we really don't know and this is something that is necessarily always going to be a theory.

My theory (4, Funny)

Algae_94 (2017070) | 1 year,19 days | (#43371101)

Unicorns would stampede the astronaut as he enters the event horizon. There's one problem with the unicorn theory. If I'm right, then either general relativity or quantum mechanics is wrong.

Re:My theory (1)

alphatel (1450715) | 1 year,19 days | (#43371223)

Unicorns would stampede the astronaut as he enters the event horizon.

I think we can all agree the astronaut would die.

Re:My theory (1)

WillAffleckUW (858324) | 1 year,19 days | (#43371235)

Unicorns would stampede the astronaut as he enters the event horizon. There's one problem with the unicorn theory. If I'm right, then either general relativity or quantum mechanics is wrong.

Fairly certain the Space Chipmunks would get him first.

Re:My theory (0)

Anonymous Coward | 1 year,19 days | (#43371253)

Then it's turtles all the way down.

Re:My theory (0)

Anonymous Coward | 1 year,19 days | (#43371401)

... and Heisenberg's uncertainty tells us that we cannot know which is wrong until we try...

He's a string theorist (0)

Anonymous Coward | 1 year,19 days | (#43371127)

He's a contradiction already since the Higgs has been found.

He would die of shock (1)

WillAffleckUW (858324) | 1 year,19 days | (#43371141)

Shock at being in a black hole in the first place.

Shock at the radiation that blasted away her face plate.

Shock that we were able to afford to get her that far from Earth, when we're shutting down airports right now.

And then her body would be torn asunder.

My new hobby (1)

tfocker4 (2750497) | 1 year,19 days | (#43371147)

Bringing up old physics thought experiments in order to throw the quantum mechanics community into an intellectual crisis.

So the consensus is still (4, Funny)

HermDog (24570) | 1 year,19 days | (#43371153)

try to avoid falling into a black hole

Re:So the consensus is still (0)

Anonymous Coward | 1 year,19 days | (#43371385)

Dunno, tripadvisor gives three out of five stars, so I guess we can't really speak of a consensus.
http://www.tripadvisor.co.uk/Hotel_Review-g297889-d2022440-Reviews-Black_Hole_Hotel-Incheon.html

You may cross alive (1)

little1973 (467075) | 1 year,19 days | (#43371173)

I once read that if the black hole is big enough tidal forces will be minimal and you can actually cross the event horizon alive.

This theory has some merit as the universe itself is a black hole from a certain point of view.

Re:You may cross alive (0)

Anonymous Coward | 1 year,19 days | (#43371441)

This theory has some merit as the universe itself is a black hole from a certain point of view.
 
Care to explain this a little better?

only small BH rips you apart (1)

peter303 (12292) | 1 year,19 days | (#43371245)

Due to the tidal grdient across your length. A large BH would have a midel tidal gradient. I dont know the size, but I think its over a trillion solar masses.

You can't have infinite density (1)

Viol8 (599362) | 1 year,19 days | (#43371319)

Infinite density = zero size and something with zero size no longer exists. If something has a presence in spacetime it will have some form of dimension. You can't have "something" that isn't actually there.

To an outside observer he'd never die (1)

TheGoodNamesWereGone (1844118) | 1 year,19 days | (#43371337)

... He'd just red-shift more and more forever

Re:To an outside observer he'd never die (1)

Jherico (39763) | 1 year,19 days | (#43371453)

This depends on the size of the black hole. The larger the black hole, the smaller the tidal forces at the actual event horizon, in which case you're correct, he just seems to slow down and redshift from an outside observer. However, for a small enough black hole he'll be ripped apart and quite dead long before he reaches the event horizon. If it's small enough to have a hot accretion disk (whether the disk is there or not).

Either way, it would be a very bad evening (0)

Anonymous Coward | 1 year,19 days | (#43371349)

I think that section of the universe could expect to have its Yelp page flamed.

If Polchinski is right... (4, Funny)

fahrbot-bot (874524) | 1 year,19 days | (#43371371)

Umm... He's a string theorist, so...

Listen to Zombie Feynman kids: Unscientific [xkcd.com] :

  • "I hunger for Braaaaaiiiinns!"
  • Uh, try the Physics lab next door.
  • "I said brains. All they've got are string theorists."

Well... (1)

Impy the Impiuos Imp (442658) | 1 year,19 days | (#43371403)

I read a different account 20 years ago -- the event horizon was not some infinite destruction area, it was just a one-way door. For supersized black holes the size of the solar system, the gravity gradient was so small you could easily fall in without being ripped apart.

Even larger ones at galactic cores should be even more gentle, from a gravity point of view anyway.

Wait, wait, I can answer this one (1)

waddgodd (34934) | 1 year,19 days | (#43371425)

The astronaut would die of starvation or hypoxia long before they got to the Black Hole, given that the farthest we've sent an astronaut is 250,000 miles (a bit more than one light-second), and the nearest black hole is 1600 light years away, or 5E+10 times as far.

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