Event horizons are no joke

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Event horizons are no joke Anonymous Tue Jul 21 13:57:06 2015 No.7411764 [Reply] [Original]

what are black holes? the majority of descriptions of them (a singularity hidden inside an event horizon) are most likely wrong. the reason for this is that infalling matter can never actually cross the event horizon within a finite timespan.

whenever an event horizon is created, an impenetrable causal boundary comes into existence. this is normally thought of as a region where no matter can escape, but the actual truth is that no matter can enter. due to the curvature of spacetime around the horizon, objects falling in can only approach it asymptotically.

you can simplistically think of the gravity well outside the event horizon as a flow in space. the deeper you are in the gravity well, the more kinetic energy you would need in order to not be pulled in further. for example, at the point where staying still would require the same amount of kinetic energy as you would have moving at 99.5% light speed in ordinary space, you could describe as a flow of 0.995c. at this level, the relativity factor of spacetime is ~10 (relativity calculator). this means that your spacetime is distorted 10x relative to a distant observer whose relativity factor is ~1.

from your point of view, their clock is ticking 10x faster than yours (they will also be lorentz contracted 10x and blue-shifted). from their point of view, your clock is ticking 10x slower than theirs (also 10x contraction and red-shift).

now, the closer you come to approaching the event horizon, the greater the flow of spacetime and the greater the factor of relativity. there will come a point where a single second that passes for you, would be the same as a trillion years for an outside observer. and it doesn't stop there. since the flow increases all the way to being equal to c at the point of the event horizon, there's no limit to the factor of relativity that can be experienced. so there would theoretically be a point where a second for you would be the same as 10^100 years for an outside observer.

Anonymous Tue Jul 21 13:58:48 2015 No.7411769
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so what this means is that all of the matter that has fallen into the black hole before you, is ahead of you, still falling. from your perspective, the matter ahead of you is all continuously slowing down, contracting, and red-shifting such that it endlessly approaches but never meets the event horizon while appearing to flatten out completely and fade to black.

since there are no reference frames outside the event horizon that allow for matter to approach the horizon in finite time, it's extremely questionable whether matter can even cross it. if the horizon did in fact have its own reference frame, it would be such that all incoming matter crosses it together, at a point in the 'infinite future' relative to the outside. who knows what that would even mean; the only thing that's clear is that an event horizon and what lies beyond somehow transcend space and time.

the dominant, singularity-based view of black holes just doesn't seem plausible when you consider the physics of an event horizon as predicted by the theories of relativity. time-dilation just never allows matter to cross that boundary, only to accumulate around it in a state of endless collapse. when a black hole grows, it's like a bubble, with all new matter collecting along an expanding 2D surface.

the model that seems to best explain the behavior of an event horizon is https://en.wikipedia.org/wiki/Magnetospheric_eternally_collapsing_object which states that 'black holes' are objects in eternal collapse, where no matter has ever crossed the horizon, and therefore have properties that a 'true' black hole couldn't, such as a magnetic field.

what does /sci/ think of a non-singularity black hole model? i've yet to hear a convincing argument that anything at or beyond an event horizon can even exist, but maybe i just haven't heard the right argument yet.

TL;DR what the fuck does any of this mean

>>	Anonymous Tue Jul 21 14:26:34 2015 No.7411816 It takes you to another dimension. :^)

>>	Anonymous Tue Jul 21 14:28:50 2015 No.7411819 >>7411769 what's that gif?

Anonymous Tue Jul 21 14:31:30 2015 No.7411823

>>7411764
>since there are no reference frames outside the event horizon that allow for matter to approach the horizon in finite time, it's extremely questionable whether matter can even cross it.
From the perspective of the falling matter, it does pass through the event horizon in finite proper time. The falling matter is outside the event horizon as it approaches it. So your entire argument is pretty pointless.

>the dominant, singularity-based view of black holes just doesn't seem plausible when you consider the physics of an event horizon as predicted by the theories of relativity. time-dilation just never allows matter to cross that boundary, only to accumulate around it in a state of endless collapse.
Only from your perspective. If you instead look at it in say, Kruskal–Szekeres coordinates, none of this weirdness occurs.

Further the singularity of the black hole is proven by the fact that changing coordinates cannot make it go away (diffeomorphism invariance), while the apparent singularity of the event horizon does go away.

>>	Anonymous Tue Jul 21 14:34:46 2015 No.7411827 >>7411819 The sun's magnetic field is highly irregular, so nothing like a bar magnet. Given that I would say that's it's likely just the effect of that irregular field.

Anonymous Tue Jul 21 14:42:52 2015 No.7411842

>>7411764
>the reason for this is that infalling matter can never actually cross the event horizon within a finite timespan.

Wrong, we just don't SEE it pass the EH in finite time. It passes thru just fine, the "never reaching the surface" is just its light-image.

Anonymous Tue Jul 21 14:47:50 2015 No.7411850

>>7411823
>From the perspective of the falling matter, it does pass through the event horizon in finite proper time.
okay, but when does that happen? the moment that something crosses the event horizon, is a point farther in the future than all outside events! so something can cross the event horizon from its own perspective, but what does that even mean, if it can only do so at the exact same moment as all of the matter in front of it?

>>7411842
nope, you're wrong. matter is in no wayexempt from the effects of relativity. the objects that seem frozen on the edge of the horizon really are there, they're not just a light image. their clocks are ticking that much more slowly relative to you, and relative to you they are really are still there slowing and contracting endlessly.

Anonymous Tue Jul 21 14:52:43 2015 No.7411858

>>7411850
>okay, but when does that happen?

pi R^(3/2) / sqrt(8GM)

source: http://www.physicspages.com/2013/09/07/event-horizon-proper-time-to-fall-into-r-0/

>the moment that something crosses the event horizon, is a point farther in the future than all outside events!
No it's not. See above.

>>	Anonymous Tue Jul 21 14:54:50 2015 No.7411863 >>7411850 You're preferring a reference frame.

>>	Anonymous Tue Jul 21 15:10:01 2015 No.7411888 >a special case where laws of physics break down >"according to laws of physics, this explanation is invalid"

Anonymous Tue Jul 21 15:28:41 2015 No.7411915

>>7411850
>matter is in no wayexempt from the effects of relativity. the objects that seem frozen on the edge of the horizon really are there, they're not just a light image.

Not from THEIR pov, they aren't! THEY see themselves go thru without problems, its only from outside that we never see them cross the horizon.

Anonymous Tue Jul 21 15:31:00 2015 No.7411917

>>7411858
okay, an object can theoretically cross the horizon in its own proper time, but my point is that time dilation makes sure this never happens from from any outside perspective. nobody outside the horizon will ever witness any matter crossing it. nothing that has 'fallen into' a black hole has actually gotten around to crossing the event horizon. matter that was captured a billion years ago would still be there collapsing just outside the boundary.

Anonymous Tue Jul 21 15:45:53 2015 No.7411935

>>7411823
Mitra's proof that black holes cannot form is based on two key proofs (i) No trapped surface is formed in general relativistic gravitational collapse and (ii) The world-line of an in-falling test particle, which must be 'Time-like' would tend to be 'Light-like' at the Event Horizon (EH) of an assumed black hole (ds_{EH}^2 \to 0). The physical interpretation of the latter proof is that the 'physical speed' of the test particle as defined by Landau & Lifshitz and all other general relativistic experts would approach the speed of light.[3] In order to avoid this, Crawford and Tereno proposed that the speed of one in-falling particle should be measured by another in-falling observer.[13] If so, the speed of the in-falling test particle could remain sub-luminal everywhere, even at the central singularity. While this could be another definition of 'velocity', Mitra claimed that it has got nothing to with his proof which is independent of the definition of 'velocity' (ds_{EH}^2 \to 0).[4][14] In fact later Crawford too admitted that "it is important to emphasize that the interior structure of realistic black holes has not been satisfactorily determined, and is still open to considerable debate".[15]

Anonymous Tue Jul 21 15:51:19 2015 No.7411942

>>7411915
i'm not saying to completely ignore their perspective, i'm just saying that from any perspective other than their own, they never ever cross the horizon. so when we're talking about black holes as they exist, we're really talking about a shell of matter collapsed around an event horizon. none of the matter has made it in yet, even though it would seem a quick journey, for all intents and purposes it's frozen in time at the horizon.

would they really see themselves go through without problems when they can only be allowed to cross at the same moment as all the other matter? until the very moment you cross the horizon, none of the matter ahead of you has crossed it either, and would only cross it when you do.

>>	Anonymous Wed Jul 22 08:41:47 2015 No.7413452 >>7411942 >until the very moment you cross the horizon, none of the matter ahead of you has crossed it either, and would only cross it when you do. is this correct? it was the first thing i thought as well, but it's really hard to visualise

>>	Anonymous Wed Jul 22 11:35:09 2015 No.7413691 I saw this theory already, basically if I understand it correctly all the absorbed matter is just "hanging there". I wonder what happens when the black hole dissipates through hawking radiation what if the universe ends before that?

>>	Anonymous Wed Jul 22 11:43:35 2015 No.7413707 >>7411764 what happens to matter thats approaching the event horizon when the event horizon radius grows? I mean it will fall into the hole from our pov wont it?

>>	Anonymous Wed Jul 22 11:51:22 2015 No.7413721 >singularity In other words, the math hits a zero/infinity and they all shout.. "wahey it's a singularity" It's bullshit

Anonymous Wed Jul 22 12:01:48 2015 No.7413736
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saw this a while ago, found it interesting
https://www.youtube.com/watch?v=2DIl3Hfh9tY
some of it seems to fit what OP is saying
(area as opposed to volume)

>>	Anonymous Wed Jul 22 12:18:50 2015 No.7413770 >>7411917 >nothing that has 'fallen into' a black hole has actually gotten around to crossing the This sounds to me like you're privileging certain reference frames above others, a violation of the principal of relativity.

Anonymous Wed Jul 22 13:09:48 2015 No.7413861

>>7413691
really depends on how the universe ends i guess.

>>7413707
it could be that the event horizon grows like a bubble, still keeping the collapsing matter just outside the surface.

>>7413736
good stuff.

>>7413770
it's true though, nothing has ever gotten around to crossing an event horizon! are you sure you're not privileging a reference frame? it's true in BOTH reference frames that the matter still hasn't made it to the event horizon.
let me repeat that i fully realize that infalling matter *should* cross the horizon in its own relative time frame, but my whole point is that this phenomenon is something that has never, ever happened. what takes a finite amount of time in a horizon-crossing reference frame, actually converges to an *infinite* amount of time in all other reference frames.

Anonymous Wed Jul 22 13:27:06 2015 No.7413885

>>7413770
>privileging certain reference frames above others

He is not - he describes how the situation looks like from certain reference frames. And it is absolutely true that a distant observer cannot possibly observe something crossing the event horizon - that is evident from the very definition of an event horizon. If you could tell that something has crossed it - you would have to be able to receive information from beyond the horizon - which would render the very idea behind 'event horizon' meaningless.

>>	Anonymous Wed Jul 22 13:30:47 2015 No.7413892 >>7413770 now that I think of it - even locally you never cross the event horizon. If you were in a spaceship flying towards the singularity, the apparent horizon would keep receideing from you.

Anonymous Wed Jul 22 13:32:14 2015 No.7413895

>>7413861
>are you sure you're not privileging a reference frame?

No. Have you done any Special Relativity? The most salient example there would be the easier to understand Muon decay experiments, basically the time measured in the rest frame of the muon is different to that measured in the rest frame of the earth, which means we observe muons at sea level even though the half life of the muon means that most should have decayed before reaching the surface. It's pretty much the same with what you're describing, two events in two reference frames that seems to lead to contradictory results, however when you transform from one reference frame to the other this contradiction dissappears.

>TLDR: The particle enters the black hole, just not in your reference frame.

Anonymous Wed Jul 22 13:34:56 2015 No.7413898

>>7413892
>If you were in a spaceship flying towards the singularity, the apparent horizon would keep receideing from you.

an event horizon isn't an apparent horizon though, it's an absolute horizon. you can't see beyond it no matter how close you get to it, so it would never appear to recede.

Anonymous Wed Jul 22 13:45:28 2015 No.7413910

>>7413895
muon decay is not the same thing as what i'm describing. in your example, the decay process in both reference frames converge to occurring within finite spans of time - while in my example, something that occurs in finite time in one reference frame becomes infinite in another.

let's say a muon is falling into a black hole, but that it's not going to have lived long enough to decay until it crosses the horizon. it's just going to asymptotically approach it forever. the muon will essentially never decay because it never actually comes into contact with the event horizon.
again, i realize that from the muon's perspective it will should reach the boundary in a finite amount of time. BUT from the perspective of anyone who isn't themselves crossing the horizon, the muon will never EVER reach the horizon.

Anonymous Wed Jul 22 13:56:43 2015 No.7413923

>>7413910
>BUT from the perspective of anyone who isn't themselves crossing the horizon, the muon will never EVER reach the horizon.

Right, and? Let me try and explain what I was trying to say in that post again. Say we have two observers, one in the rest frame of the earth and one in the rest frame of the muon, if these two observers made a measurement of the half life they would get two different results. There is no problem in this, in fact given what we know of relativity we would expect that. Your example is odd, certainly, but it presents no more issue than getting two different results for the half life of the muon.

>>	Anonymous Wed Jul 22 13:59:53 2015 No.7413925 >>7413885 >He is not He is, he's saying nothing has fallen into a black hole because he didn't see happen in his reference frame, that's privileging his reference frame above that of the particles.

>>	Anonymous Wed Jul 22 14:03:11 2015 No.7413930 >>7411764 1/10 one of the most retarded thing I've read this week on /sci/. fuck, /sci/ really is one of the shittiest boards here

Anonymous Wed Jul 22 14:05:24 2015 No.7413936

>>7411764
>>7411769
Like literally glanced at every second line, but OP it is quite possible that each black hole in the universe is independantly responsible for each peice of mass in their vicinity. Which means that the only freely decaying consciousness is in between black holes in the, surprisingly populated, between spaces of these black holes.
Which ontop of being quite a view would also allow for more superhuman attributes to express themselves, which, all I'm saying is, a very possible future for human beings.
>this is just assuming you've seen some of the videos that are out there and even this guy on Ellen https://www.youtube.com/watch?v=b_xhSQGKxO4

Anonymous Wed Jul 22 14:05:49 2015 No.7413937

>>7413923
and so the muon effectively NEVER decays, except from it's own reference frame, but that's where the paradox lies. two different results for the half life of the muon are perfectly fine because they're both finite values. the disparity between reference frames when matter is falling into a black hole is NOT the same, because the process takes an INFINITE amount of time in any reference frame that doesn't cross the horizon.

there is no matter in existence that has ever crossed an event horizon. that is the point of my argument.

>>	Anonymous Wed Jul 22 14:09:12 2015 No.7413942 >>7413925 >privileging his reference frame above that of the particles. actually a she. also that's wrong. it holds true that in ALL reference frames, none of the particles have yet made it to the event horizon.

Anonymous Wed Jul 22 14:10:30 2015 No.7413945

>>7413937
>that is the point of my argument.
No the point of your argument is that no matter has ever fallen into a black hole from an outside frame, now this isn't wrong, but we could always transform into the rest frame of the particle to see that it has indeed fallen into the black hole, in much the same way our observers can transform the value of the half life into each others respective frames to discover that they are the same value. As for the rest of your post, the same reasoning can be applied even if one value is infinite.

>>	Anonymous Wed Jul 22 14:12:33 2015 No.7413946 >>7413936 EEEUURROPE HERE I COME!!!

Anonymous Wed Jul 22 14:13:37 2015 No.7413950

>>7413945
> we could always transform into the rest frame of the particle to see that it has indeed fallen into the black hole
absolutely wrong! if you switch to the rest frame of the particle, it's still outside the event horizon! there's no debating this fact.

>>	Anonymous Wed Jul 22 14:14:59 2015 No.7413951 >>7413942 >actually a she. Sorry, me lady. > it holds true that in ALL reference frames This is wrong, the particle enters the black hole in finite proper time. "Issue" is with the coordinate time.

Anonymous Wed Jul 22 14:19:50 2015 No.7413962

>>7413951
>This is wrong, the particle enters the black hole in finite proper time. "Issue" is with the coordinate time.
it's not wrong! none of the particles that are being pulled into a black hole have yet made it to the event horizon. it doesn't matter what reference frame you're talking about.

Anonymous Wed Jul 22 14:27:08 2015 No.7413971
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>>7413962
>>7413950
This is completely wrong, the particle reaches the horizon in finite proper time, pic related.

Schutz, Bernard "A first Course in general relativity, second edition" (CUP,2014)

>"There is nothing wrong with this statement.... "

Anonymous Wed Jul 22 14:37:54 2015 No.7413983

this relativity of time issue has to have a boundary isn't it? when you say depending on the gravitation a second to you will be equal to trillion years for others we have to consider the age of the universe. an immesurably small fraction of a second has passed for any object within a dense gravitational field then. Then it's not even enough to complete the most basic of fundamental matter interactions. Matter near a black hole may as well not exist with respect to time passing outside

Anonymous Wed Jul 22 14:43:05 2015 No.7413991

>>7411764
>you can simplistically think of the gravity well outside the event horizon as a flow in space.
Sure, this is one way to picture it.
http://casa.colorado.edu/~ajsh/schwp.html#freefall

>from your point of view, their clock is ticking 10x faster than yours
Only if you are maintaining your altitude. If you are falling at the same speed as the flowing space, there is no time difference.

So this
>so what this means is that all of the matter that has fallen into the black hole before you, is ahead of you, still falling.
is not true in this coordinate system.

>from your perspective
I think you are misapplying concepts from special relativity here. In special relativity, for every massive non-accelerating object, there is a unique inertial reference frame in which it is at rest. This no longer works in general relativity. There are no more inertial reference frames anymore, and you have to make things work in arbitrary coordinate systems. In other words, if A and B are lightlike separated, "did A come before B?" is dependent not on the observer but on the arbitary choice of coordinate system.

>Magnetospheric_eternally_collapsing_object
I remember this shit. This is just a crackpot who "disproved" that black holes can form with some basic calculus mistakes, and refuses to admit he is wrong.

>>	Anonymous Wed Jul 22 14:43:13 2015 No.7413993 >>7411827 There's a sphere, it's a fucking space ship.

>>	Anonymous Wed Jul 22 14:46:03 2015 No.7413999 >>7413895 There are no particles until after a measurement is made you fucking amateur! Seriously, call yourself /sci. Embarrassing.

Anonymous Wed Jul 22 14:58:12 2015 No.7414017 [DELETED]

>>7413971
>This is completely wrong, the particle reaches the horizon in finite proper time, pic related
i've already discussed this. it ONLY reaches the horizon in finite proper time in its own reference frame. in any reference frame that doesn't cross the event horizon, this process takes an INFINITE amount of time.

Anonymous Wed Jul 22 15:02:36 2015 No.7414026

>>7413971
>This is completely wrong, the particle reaches the horizon in finite proper time, pic related
i've already discussed this. it ONLY reaches the horizon in finite proper time in its own reference frame. in any reference frame that doesn't cross the event horizon, this process takes an INFINITE amount of time.

also still not wrong, because like i said none of the matter falling in has YET crossed the event horizon, if you think it has then you would be wrong.

Anonymous Wed Jul 22 15:08:03 2015 No.7414035

>>7414026
You're retarded, I'm going to bed now. Please go read a book, Schutz is good but I prefer Hobson et al. Stay away from Wald it's not so friendly to as a first Course. As for SR the standard reference is French, there's a book in springer undergraduate mathematics series called Special Relativity that's probably a more modern introduction, so I'd say French -> Springer -> Schutz -> Hobson ->Wald.

>>	Anonymous Wed Jul 22 15:08:52 2015 No.7414037 >>7413993 if it were, it would be like the size of fucking jupiter. i think it's more likely some feature of a solar prominence, though you can never rule out aliens stopping by with their planet-sized ship to siphon off some plasma.

>>	Anonymous Wed Jul 22 15:12:25 2015 No.7414043 File: 3 KB, 125x108, bahlegdeh.jpg [View same] [iqdb] [saucenao] [google] >>7414035 lol you didn't have to be rude, but thanks for the resources anyway.

>>	Anonymous Wed Jul 22 15:12:56 2015 No.7414046 >>7413885 The lack of information being sent is just as informative as a message sent from beyond the event horizon.

>>	Anonymous Wed Jul 22 15:15:42 2015 No.7414048 >>7414026 You just said "it holds true that in ALL reference frames". So you're wrong.

Anonymous Wed Jul 22 15:22:00 2015 No.7414056

>>7414048
it is true that in ALL reference frames, none of the particles have YET made it to the horizon! are you disputing this? it makes no difference what reference frame you switch to, all matter is still outside of any event horizon.

yes, from the point of view of the matter, it would quickly make the journey across. but my whole point is that this hasn't happened yet.

Anonymous Wed Jul 22 15:25:11 2015 No.7414061

>>7414056
Yes I am disputing this. From the reference fram of the particle falling it reaches the horizon in proper time.

>yes, from the point of view of the matter, it would quickly make the journey across. but my whole point is that this hasn't happened yet.
For the matter inside the event horizon it has. Where are you getting this bullshit from?

Anonymous Wed Jul 22 15:28:01 2015 No.7414066

>>7414061
>Yes I am disputing this. From the reference fram of the particle falling it reaches the horizon in proper time.

it WILL reach the horizon in it's own proper time. but this hasn't happened yet! therefore, regardless the reference frame, all matter at this point in time is STILL outside of any event horizon!

>For the matter inside the event horizon it has. Where are you getting this bullshit from?
it hasn't yet though! it's still falling in! you're talking about something that hasn't even happened yet!

Anonymous Wed Jul 22 15:32:00 2015 No.7414074

>>7414066
>it WILL reach the horizon in it's own proper time. but this hasn't happened yet!
OK, so wait a bit and it has happened and you're wrong. All you are doing is defining all particles as not falling in yet and then acting amazed that none of them have fallen in yet. What about the ones that already fell in? Trolling or retarded?

Anonymous Wed Jul 22 15:40:14 2015 No.7414095

>>7414074
they effectively WON'T fall in for reasons i've already explained. time dilation slows down matter's clock to a virtual standstill directly outside the horizon. particles that the black hole pulled in a billion years ago are still directly outside the horizon, compressing infinitely underneath everything else that has accumulated since. there is no matter that already fell in. what you're not getting is that no matter has ever crossed an event horizon. like i've said, what takes a finite amount of time for a horizon-crossing reference frame, converges to infinity in any reference frame that stays outside the horizon.

>>	Anonymous Wed Jul 22 15:41:56 2015 No.7414102 >>7414095 >time dilation slows down matter's clock to a virtual standstill directly outside the horizon. To external observers. For all internal observers the particle falls into the black hole.

>>	Anonymous Wed Jul 22 15:45:41 2015 No.7414111 okay! but my point is - there are no internal observers! no matter has yet made it to an event horizon!

>>	Anonymous Wed Jul 22 15:45:57 2015 No.7414114 Why don't we send something through a black hole

>>	Anonymous Wed Jul 22 15:46:46 2015 No.7414116 >>7414111 reply to this: >>7414102

Anonymous Wed Jul 22 15:51:22 2015 No.7414125

>>7414111
Holy fuck, you're for real aren't you. Okay lets say you're travelling towards a black hole and I'm some distant observer, as you get closer and closer I see your clock slow down, as you approach the the event horizon your clock slows to a stand still out side the horizon.

>MEANWHILE

On your ship, you're still heading towards the black hole, when you look at your clock you see it tick normally, you begin to approach the event horizon eventually (after a finite amount of time) you pass through the horizon.

Both of these things happen, neither is wrong. To one observer you never pass the horizon while to the other you do.

Anonymous Wed Jul 22 15:51:55 2015 No.7414127

>>7414095
>they effectively WON'T fall in for reasons i've already explained.
Let's go over your argument:
1. To outside reference frames, matter doesn't fall in
2. This means they won't fall in
3. So they won't fall in all reference frames

Do you not see how this nonsensical?

>time dilation slows down matter's clock to a virtual standstill directly outside the horizon.
As was already shown to you, it doesn't. You can calculate the finite proper time for a particle to fall in from its perspective. Why do you keep ignoring this?

>particles that the black hole pulled in a billion years ago are still directly outside the horizon, compressing infinitely underneath everything else that has accumulated since.
Not from their own perspective. This is just obviously false bootstrapping.

>what you're not getting is that no matter has ever crossed an event horizon.
That's what you're trying to prove, but you're failing. You need to give a reason why the matter is not allowed to go through when from its own perspective it is clearly allowed. So far all you've done is use circular reasoning that isn't even based on facts.

>>7414111
Your argument is simply: matter hasn't fallen in therefore it hasn't fallen in. But you never proved the premise.

>>	Anonymous Wed Jul 22 15:56:24 2015 No.7414135 File: 41 KB, 640x719, sheev.jpg [View same] [iqdb] [saucenao] [google] Falling in is a point of view, Anakin.

>>	Anonymous Wed Jul 22 16:04:32 2015 No.7414145 Forget black holes -- nothing ever falls through the Rindler horizon! https://en.wikipedia.org/wiki/Rindler_coordinates

Anonymous Wed Jul 22 16:14:44 2015 No.7414157 [DELETED]

>>7414125
>Let's go over your argument:
>1. To outside reference frames, matter doesn't fall in
>2. This means they won't fall in
>3. So they won't fall in all reference frames
i have acknowledged that they will fall in in their own reference frame. but as far as the entire universe outside of that event horizon is concerned, the matter never makes it in. it approaches it asymptotically - nobody in this universe will ever witness matter crossing an event horizon regardless of the amount of time that's passed.

>As was already shown to you, it doesn't. You can calculate the finite proper time for a particle to fall in from its perspective. Why do you keep ignoring this?

i'm not ignoring this. i'm just pointing out that this fact doesn't reconcile with the fact that this would take an infinite amount of time from a reference frame not entering the horizon. hence no matter has ever crossed one. only by crossing a horizon yourself, would you be able to witness anything else crossing. UNTIL you do that, all matter in the universe is outside of an event horizon.

>That's what you're trying to prove, but you're failing. You need to give a reason why the matter is not allowed to go through when from its own perspective it is clearly allowed. So far all you've done is use circular reasoning that isn't even based on facts.
both reference frames are valid, but you have to recognize the fact that crossing of the horizon simply doesn't occur from an outside frame. the matter WILL cross the horizon, but the timeline for when this will happen from the perspective of the outside universe converges to an infinite point in the future. i'm not saying matter CAN'T cross a horizon, i'm just saying it won't on our time.

Anonymous Wed Jul 22 16:17:45 2015 No.7414159

>>7414127
>Let's go over your argument:
>1. To outside reference frames, matter doesn't fall in
>2. This means they won't fall in
>3. So they won't fall in all reference frames
i have acknowledged that they will fall in in their own reference frame. but as far as the entire universe outside of that event horizon is concerned, the matter never makes it in. it approaches it asymptotically - nobody in this universe will ever witness matter crossing an event horizon regardless of the amount of time that's passed.

>As was already shown to you, it doesn't. You can calculate the finite proper time for a particle to fall in from its perspective. Why do you keep ignoring this?

i'm not ignoring this. i'm just pointing out that this fact doesn't reconcile with the fact that this would take an infinite amount of time from a reference frame not entering the horizon. hence no matter has ever crossed one. only by crossing a horizon yourself, would you be able to witness anything else crossing. UNTIL you do that, all matter in the universe is outside of an event horizon.

>That's what you're trying to prove, but you're failing. You need to give a reason why the matter is not allowed to go through when from its own perspective it is clearly allowed. So far all you've done is use circular reasoning that isn't even based on facts.
both reference frames are valid, but you have to recognize the fact that crossing of the horizon simply doesn't occur from an outside frame. the matter WILL cross the horizon, but the timeline for when this will happen from the perspective of the outside universe converges to an infinite point in the future. i'm not saying matter CAN'T cross a horizon, i'm just saying it won't on our time.

>>	Anonymous Wed Jul 22 16:21:57 2015 No.7414167 >>7414056 >it is true that in ALL reference frames, none of the particles have YET made it to the horizon! >>7414159 > i'm not saying matter CAN'T cross a horizon, i'm just saying it won't on our time. Damage_control.jpg

Anonymous Wed Jul 22 16:22:13 2015 No.7414168

>>7414159
>but as far as the entire universe outside of that event horizon is concerned, the matter never makes it in.
So what?

>i'm just pointing out that this fact doesn't reconcile with the fact that this would take an infinite amount of time from a reference frame not entering the horizon.
It reconciles because of relativity.

>hence no matter has ever crossed one. only by crossing a horizon yourself, would you be able to witness anything else crossing. UNTIL you do that, all matter in the universe is outside of an event horizon.
That's not how physics works. Because we understand relativity, we can get knowledge about matter falling into a black hole without directly seeing it. We can explain exactly why we are seeing what we are seeing and why this also means matter is falling in.

>both reference frames are valid, but you have to recognize the fact that crossing of the horizon simply doesn't occur from an outside frame.
When did I not recognize this?

Anonymous Wed Jul 22 16:34:53 2015 No.7414192

>>7414167
um, i didn't contradict myself. no matter has yet made it to any horizon. it will make it on its own time, but not on ours.

>>7414168
>So what?
so ... any matter that ever has or ever will start falling into black hole is never going to make it in as long as this universe will be around! you could go any arbitrary distance into the future, and all the matter from however long ago will still be collapsing around the event horizon. it doesn't matter how far into the future you go, it will still be there. if you had the means, you could even pluck out matter that started falling in any arbitrary time in the past.

>we can get knowledge about matter falling into a black hole without directly seeing it.
this is where you're not getting it. you would SEE the matter just outside the event horizon because it's STILL THERE. it's not some sort of light echo or whatever, the physical matter is still there right where you see it.

>When did I not recognize this?
by not recognizing the fact that because of matter's asymptotic approach to an event horizon, means that matter will never reach an event horizon within the lifetime of this universe.

>>	Anonymous Wed Jul 22 16:37:20 2015 No.7414199 >>7414192 >so ... any matter that ever has or ever will start falling into black hole is never going to make it in Gadzooks, it's like talking to a fucking wall.

Anonymous Wed Jul 22 17:03:54 2015 No.7414247

>>7414192
>so ... any matter that ever has or ever will start falling into black hole is never going to make it in as long as this universe will be around!
Only from your perspective. Does this mean the description of the black hole is wrong? No. So the premise of your thread is false. Learn how to understand the difference between a description of something and a description of what you can see of something. They are not the same thing.

Anonymous Wed Jul 22 17:29:56 2015 No.7414302
File: 1.81 MB, 150x150, Spine-like_2.gif [View same] [iqdb] [saucenao] [google]

>so what this means is that all of the matter that has fallen into the black hole before you, is ahead of you, still falling. from your perspective, the matter ahead of you is all continuously slowing down, contracting, and red-shifting such that it endlessly approaches but never meets the event horizon while appearing to flatten out completely and fade to black
>TL;DR what the fuck does any of this mean

Sounds like the picture we get of the universe; mostly red-shifted objects fading away into a black nothingness.

Why does the matter ahead of you never reach the event horizon? Because there's no matter moving through space; each point in space carries a record of every change that's ever occurred within it. Via the proper series of actions, a point or arbitrary collection of points can be returned to any previous - or future - state. An object moving through space is a wave of state changes, and the subjective perception of the observer noting the red-shift and fade into black is itself composed of state changes within the observer - state changes caused by reflection of the observed object's 'state change wave' which arrived at non-instantaneous, relativistic speeds.

Every moment of the object's movement towards the event horizon exists simultaneously, and the moment perceived depends on your position relative to the object. Every point is a hologram, reflecting everything that has ever happened within it, and which will ever happen within it in the future.

So than what creates the wave, if all states exist simultaneously? The observer, who flows through matter along a one dimensional stream, and looks at each point in the stream from the perspective needed to produce the expected chain of causality - which can't be violated because the universe is deterministic. Every state is already determined - the observer simply chooses between predetermined states.

>>	Anonymous Wed Jul 22 17:35:15 2015 No.7414308 http://www.pbs.org/wgbh/nova/next/physics/black-holes-could-turn-you-into-a-hologram-and-you-wouldnt-even-notice/ New theory.

>>	Anonymous Wed Jul 22 22:17:49 2015 No.7414774 >>7413993 Yeah I agree. That looked more like a living thing or structure than a solar presence to me. Spooky as all hell too

>>	Anonymous Wed Jul 22 22:43:35 2015 No.7414806 >>7413993 pretty sure it's just an image abberation from the freaking plasma tornado. I mean you don't look at distortion spikes and think Jesus is out there to save you.

Anonymous Wed Jul 22 23:59:24 2015 No.7414892

>>7414199
>>7414247
i was talking about the reference frame of the universe outside the event horizon here, though i should have been more clear on that.

neither of you dispute the fact that matter approaches asymptotically from any outer perspective, so i'm not really sure what you're not getting about the fact that the matter will always be outside the event horizon from an outer reference frame. it's not just an illusion that the matter still appears outside of it - it's really still there and will really still not have crossed 10^100 years in the future (outer frame).

until matter gains the magical ability to cross a horizon in finite proper time with respect to the OUTER reference frame, my argument still stands.

i'll break it down if you're still not getting it:
>matter never ever reaches an event horizon with respect to any outer reference frame
>regardless of reference frame, the matter is in the same place
>with a co-moving frame, the matter is just instants away from crossing
>it doesn't matter how far into the future you travel in an outer reference frame, that same matter will still be an instant away from crossing in its own reference frame
>therefore, no matter has yet crossed any event horizon. all of it is still on the very last moments of its journey within its own frame, which translates to an eternity of remaining time with respect to the outer
>to reiterate, even though matter should quickly cross from its own perspective, this process takes an infinite amount of time from any outer perspective. it doesn't only appear to, it really does take forever from that point of view

Anonymous Thu Jul 23 00:22:07 2015 No.7414907

>>7414892
>the reference frame of the universe outside the event horizon
>the fact that the matter will always be outside the event horizon from an outer reference frame
>the OUTER reference frame
This is a misconception, as I explained in >>7413991. There are coordinate systems in which the object falls in before the outside guy turns 10^100 years old or whatever, and there are coordinate systems in which the object falls after he turns 10^100. Neither is privileged, not even when you've singled out an observer. This is not special relativity.

Anonymous Thu Jul 23 00:38:19 2015 No.7414927

>>7414907
>There are coordinate systems in which the object falls in before the outside guy turns 10^100 years old or whatever
i don't fully understand. could you describe a coordinate system that would allow for this? is my understanding that objects approach an event horizon asymptotically with respect to any outside reference frame, wrong?

>>	Anonymous Thu Jul 23 00:47:07 2015 No.7414941 >>7414927 See http://casa.colorado.edu/~ajsh/schwp.html which shows several coordinate systems, of which only the first (Schwarzschild coordinates) has the event horizon pushed out to the infinite future.

>>	Anonymous Thu Jul 23 01:04:46 2015 No.7414958 >>7414941 but in all these examples, the 'observer' is themselves falling past the event horizon. none of these talk about the perspective of an outside observer, who can only witness matter approaching the event horizon asymptotically.

Anonymous Thu Jul 23 01:12:27 2015 No.7414967

>>7414958
>but in all these examples, the 'observer' is themselves falling past the event horizon.
This "observer" stuff is a misconception. A coordinate system doesn't have an "observer" and isn't a "perspective."

>none of these talk about the perspective of an outside observer, who can only witness matter approaching the event horizon asymptotically.
Look again. All of them describe the experience of an outside observer. And all but the first describe the experience of an infalling observer.

>>	Anonymous Thu Jul 23 01:43:43 2015 No.7414997 File: 182 KB, 1280x1920, sun031_PPT_313702180.jpg [View same] [iqdb] [saucenao] [google] >>7411764 dis is a black holes

Anonymous Thu Jul 23 01:49:07 2015 No.7415003

>>7414967
but a coordinate system can correspond to a perspective. if you'll notice, there's not a single coordinate system depicted where either the time metric or the light rays' world lines aren't asymptotic along the event horizon. this shows that either the light ray reaches the event horizon in finite proper time, but traverses an infinite amount of schwarzschild time doing so - or the light ray approaches the horizon endlessly as an asymptote. these correspond to the horizon-crossing and outer perspectives, respectively. a crossing that takes place in a finite amount of proper time in one, converges to infinity in the other.

Anonymous Thu Jul 23 02:03:25 2015 No.7415012

>>7415003
>this shows that either the light ray reaches the event horizon in finite proper time,
In fact, I think you'll find that the light rays reach the horizon in *zero* proper time.

>but traverses an infinite amount of schwarzschild time doing so
It certainly does. But Schwarzschild time isn't a physical thing. It's a just coordinate, like longitude.

>these correspond to the horizon-crossing and outer perspectives
This is where you're wrong. The outer perspective is fully shown in all diagrams by the purple lines.

Anonymous Thu Jul 23 02:22:40 2015 No.7415021

>>7415012
>In fact, I think you'll find that the light rays reach the horizon in *zero* proper time.
unless you're talking about the 'perspective' of a light ray, light takes a finite amount of time to traverse space.

>The outer perspective is fully shown in all diagrams by the purple lines.
which forms an asymptote along the event horizon in any coordinate system where the worldlines don't.

i still don't see how any of this challenges the notion that matter can only approach an event horizon asymptotically within the outer reference frame. help me understand.

Anonymous Thu Jul 23 02:26:04 2015 No.7415026

>>7415021
>unless you're talking about the 'perspective' of a light ray
That's what you said. Proper time.

>which forms an asymptote along the event horizon in any coordinate system where the worldlines don't.
Sorry, my mistake. The *blue* lines represent outside observers.
The purple lines don't correspond to anything physical.

Anonymous Thu Jul 23 02:46:58 2015 No.7415058

>>7415026
>That's what you said. Proper time.
you're right. my mistake.

>The *blue* lines represent outside observers.
>The purple lines don't correspond to anything physical.
blue corresponds to distances relative to an outside observer, and purple corresponds to their time. the schwarzschild diagram is the only one that describes what behavior of light an outside observer would see.

you still haven't addressed
>the notion that matter can only approach an event horizon asymptotically within the outer reference frame

Anonymous Thu Jul 23 02:54:48 2015 No.7415067

>>7415058
>blue corresponds to distances relative to an outside observer, and purple corresponds to their time
I can draw the purple lines anywhere I want, and they'll still be a perfectly valid time coordinate. The blue lines, on the other hand, do follow the path of an outside observer, so they have some physical meaning.

>>	Anonymous Thu Jul 23 03:09:25 2015 No.7415086 >>7415067 >I can draw the purple lines anywhere I want, and they'll still be a perfectly valid time coordinate the only valid configuration for time coordinates with respect to an outside observer, is where it becomes asymptotic at the event horizon.

>>	Anonymous Thu Jul 23 03:11:56 2015 No.7415090 >>7415086 That's wrong. Why do you think that? All of the time coordinates shown would work fine for keeping track of an outside observer's time.

Anonymous Thu Jul 23 03:12:07 2015 No.7415091

I see what you're saying OP, though I've always had a bit of trouble with relativity thought experiments.
If from coordinate system A, an event in system B is observed to take an infinite time (on A's clock), does this mean that from B, during this event, they also observed in infinite amount of time pass on A's clock?

>>	Anonymous Thu Jul 23 03:12:47 2015 No.7415093 How big is a black hole? The event horizon can vary but the "solid matter" inside? Does that change too? I have an idea that a black hole has a surface but does theory support this or is it some bullshit infinite small point?

Anonymous Thu Jul 23 03:16:15 2015 No.7415097

>>7411935
Nobody actually knows what happens to matter as it approaches c. It's already in the grips of a black hole, so the gravitational forces on it are tremendous and also approaching the same kind of breaking point, with respect to space-time.

For all we know, matter is converted to energy during this process. Problem solved, assuming there is relationship between energy, the space-time singularity, and it's effective mass.

>>	Anonymous Thu Jul 23 03:16:46 2015 No.7415098 >>7415093 At some point during the star's collapse, the physics we know ceases to be valid. So we don't really know.

>>	Anonymous Thu Jul 23 03:18:20 2015 No.7415102 >>7415093 space-time is collapsed to a singularity, "inside" a black hole, dude. there are no spatial dimensions. there is no space for matter to exist as we know it.

>>	Anonymous Thu Jul 23 03:18:23 2015 No.7415103 >>7415097 >Nobody actually knows what happens to matter as it approaches c. I know, it's not as if scientists have built machines that do this to particles.

>>	Anonymous Thu Jul 23 03:21:20 2015 No.7415107 >>7415090 because all the prior research i've done on the subject has pointed to matter approaching an event horizon as an asymptote as viewed from any outer perspective. is this wrong?

Anonymous Thu Jul 23 03:21:38 2015 No.7415108

>>7415103

>what is exponential returns

you retard. there is a cosmic fucking gulf between 95% or 99% or even 99.9% of c, and actually symptotically approaching c. and certainly if you actually attain c somehow, considering its mathematically undefinable..

>>	Anonymous Thu Jul 23 03:24:57 2015 No.7415114 What would happen if every black hole in the universe were redistributed into normal matter and it from now on was impossible for any future black hole to form? Would galaxies start to split up or would there happen anything at all?

Anonymous Thu Jul 23 03:27:29 2015 No.7415116

>>7415107
An outside observer will certainly *see* (as in observe with light) the object take an infinite amount of time to fall in. That's because light from the event horizon can't escape.

Whether the object actually has fallen in at any given moment in the outside observer's life is a matter of convention, not perspective. Using different time coordinates, you can get different answers for whether something is in the past or future.

Anonymous Thu Jul 23 03:30:00 2015 No.7415120

>>7415114
What do you mean black holes would be impossible to form? It seems like everything would be exactly the same, except instead of black holes the matter would just be the next closest thing like gigantic neutron stars. In terms of collections of stars like galaxies and clusters nothing would change.

>>	Anonymous Thu Jul 23 03:31:27 2015 No.7415125 >>7415108 >you retard. kek >there is a cosmic fucking gulf between 95% or 99% or even 99.9% of c all attained >and actually symptotically approaching c. Nothing is doing this, though.

Anonymous Thu Jul 23 03:31:34 2015 No.7415126

>>7415116
but it's not like it's the light that's trapped there, the object itself would still be there!

whether the object actually has fallen in at any given moment in the outside observer's life is a matter of fact. the observer will never see matter cross the horizon because it's an event that simply doesn't happen from their perspective. if you had the means, you could pluck out matter that had started falling long ago, because it will have still not crossed the horizon no matter how much time passes for you.

Anonymous Thu Jul 23 03:31:34 2015 No.7415127

>>7414159

Someone with only a small understanding of relativity replying here,

>i have acknowledged that they will fall in in their own reference frame. but as far as the entire universe outside of that event horizon is concerned, the matter never makes it in. it approaches it asymptotically - nobody in this universe will ever witness matter crossing an event horizon regardless of the amount of time that's passed.

Yeah, no-one outside will ever see it happen.

>>7414192
>so ... any matter that ever has or ever will start falling into black hole is never going to make it in as long as this universe will be around!

Why would this apply to 'has ever'? You weren't observing it, so from your current reference frame, it already happened, and there's not even an apparent contradiction.

As I understand it, the object falling in could send out a regular pulse, and to you, outside, it would take longer and longer for these pulses to reach you, until eventually they appear to stop / take forever - but for the object, it was sending these pulses regularly all the way in, but (here's the point where I might fail to take something into account and over-simplify as a result, if I haven't already) it was never knowing if/when you were receiving the pulse (and I'd think if it somehow did, it would notice the receipt of the pulses was taking longer and longer - if it had time to notice such a thing before it crossed the horizon), and the fact that at some point you will stop receiving its signal makes no difference to the object whatsoever.

Any of that right?

>>	Anonymous Thu Jul 23 03:35:10 2015 No.7415132 File: 1007 KB, 332x187, mfwtheDMTkicksin.gif [View same] [iqdb] [saucenao] [google] >>7411769 >literal space monsters exist

Anonymous Thu Jul 23 03:36:34 2015 No.7415133

>>7415126
>whether the object actually has fallen in at any given moment in the outside observer's life is a matter of fact.
Nope, and understanding this is the first crucial step to understanding relativity. There is no universal present like in Newtonian mechanics. You should think of time as the fourth dimension of space.

Anonymous Thu Jul 23 03:36:53 2015 No.7415134

>>7415127
>Why would this apply to 'has ever'? You weren't observing it, so from your current reference frame, it already happened, and there's not even an apparent contradiction.
the only thing that already happened is that it STARTED falling. there's no matter that has already crossed the horizon.

>Any of that right?
yup.

>>	Anonymous Thu Jul 23 03:39:51 2015 No.7415136 If someone dropped a micro black hole on the ground how many years would we have before the core would collapse in on itself?

>>	Anonymous Thu Jul 23 03:40:30 2015 No.7415138 >>7415133 but an observer could theoretically catch up to matter that started falling in any time in the past, without crossing the event horizon. how is this not the same as the matter not having crossed the event horizon yet?

>>	Anonymous Thu Jul 23 03:41:35 2015 No.7415141 >>7415138 >but an observer could theoretically catch up to matter that started falling in any time in the past, without crossing the event horizon. No, they couldn't. To do so would require them to exceed the speed of light.

>>	Anonymous Thu Jul 23 03:44:13 2015 No.7415146 >>7415136 Would evaporate too quickly

>>	Anonymous Thu Jul 23 03:49:18 2015 No.7415153 >>7415146 But it would start digging thin tunnels and gain mass tho.

>>	Anonymous Thu Jul 23 03:50:59 2015 No.7415155 >>7415146 Depends on how large it is.

>>	Anonymous Thu Jul 23 03:52:30 2015 No.7415156 >>7415141 >To do so would require them to exceed the speed of light. it wouldn't though. the matter is subluminal until it reaches the event horizon, so it could be caught up to before then.

Anonymous Thu Jul 23 03:56:53 2015 No.7415159

A black hole weighing 606,000 metric tons (this is about the mass of the Seawise Giant, the longest sea-going ship ever built) would have a Schwarzschild radius of 0.9 attometers, a power output of 160 petawatts, and a 3.5 year lifespan.

BLACK HOLE POWER NOW

>>	Anonymous Thu Jul 23 03:57:33 2015 No.7415161 File: 9 KB, 244x217, stff.gif [View same] [iqdb] [saucenao] [google] >>7415156 Yellow is infalling light; green are infalling objects. At some point, you (purple) are no longer able to beat green to the event horizon without going faster than yellow.

>>	Anonymous Thu Jul 23 03:58:34 2015 No.7415162 >>7415161 >you (purple) Sorry, fucked that up again. You are blue.

>>	Anonymous Thu Jul 23 04:32:36 2015 No.7415200 File: 17 KB, 244x217, schwarzschild-time.png [View same] [iqdb] [saucenao] [google] >>7415161 ooh, you're right. why though doesn't the same seem to hold true in schwarzschild time?

>>	Anonymous Thu Jul 23 04:49:27 2015 No.7415231 >>7415200 You can't tell either way from that diagram because Schwarzschild time is putting anything that happens on the event horizon out at t=<span class="math">\infty[/spoiler].

>>	Anonymous Thu Jul 23 05:18:28 2015 No.7415271 >>7415231 you can tell though, from the relative slopes between the sets of worldlines. you can deduce that any arbitrary light ray will eventually pass any arbitrary falling object, unlike with free-fall coordinates.

>>	Anonymous Thu Jul 23 05:33:51 2015 No.7415297 File: 40 KB, 244x217, stffs.gif [View same] [iqdb] [saucenao] [google] >>7415271 All I can say is you're trying to extrapolate and getting it wrong. There's no difference between the two.

Anonymous Thu Jul 23 05:40:02 2015 No.7415306

>>7414061
I have no in depth understanding of the topic, but you seem to be intentionally ignoring the OP's point just because he made a fairly small error.

I believe the idea behind it is that there are no real implications to it crossing the event horizon in its own finite time. After all, for the entirety of its existence to the outside observer, the matter would exist in an infinitely dense shell on the event horizon. This would also play into any interactions that it has with the outside universe.

Moreover, if you have any energy loss from Hawking radiation, wouldn't any black hole have completely dissipated before any matter crossed that shell in its own reference frame, or is there something that would make that a non-factor?

>>	Anonymous Thu Jul 23 05:48:39 2015 No.7415314 >>7413925 >he's saying nothing has fallen into a black hole ...from all the reference frames outside of the black hole. This is relativity 101.

>>	Anonymous Thu Jul 23 05:53:04 2015 No.7415319 >>7415314 And that's wrong.

>>	Anonymous Thu Jul 23 10:08:24 2015 No.7415640 How come black holes so complicated? Isn't a black hole just a big sphere of mass that exceeds the schwarzschild radius?

Prof Sai Thu Jul 23 10:18:29 2015 No.7415656

OP's argument makes perfect sense to me, I don't understand the objection.

Someone falling into the universe can see outside just fine. Imagine they are falling into the black hole, while watching a clock in the distance. What does the distant clock read when they reach the event horizon? It seems it would have an infinite value.

I'd add that since Stephen Hawking predicted that black holes evaporate, any falling observer would see the black hole do this before s/he got there, and so never reach a singularity. (In fact, they might survive indefinitely because of this.)

>>	Anonymous Thu Jul 23 10:31:45 2015 No.7415670 >>7411769 Is there any explanation for gamma ray bursts from black holes in this theory?

Anonymous Thu Jul 23 10:32:18 2015 No.7415672

>>7411823
Indeed, in Kruskal coordinates you get rid of thw singularity at the Schwarzschild-radius, but they do not represent what we intuitively define as time anymore. In the book of Fließbach I have seen a formula for the trajectory of an object approaching the SR in the frame of a distant observer. Except for some constants, it was R(t) = R_s + const*exp(-t/T). I think that proves what OP said.

I had the same argument with my GR tutor and he thought that the objects are actually falling in but we don't see it due to infinite redshift. But the formula from Fließbach states the opposite...

>>	Anonymous Thu Jul 23 10:33:37 2015 No.7415674 I'll quote someone from my high school that I agree with to this day "Black holes scare me because that shit literally fucks with time".

Anonymous Thu Jul 23 10:35:46 2015 No.7415677

>>7415656
>What does the distant clock read when they reach the event horizon? It seems it would have an infinite value.

while i already knew this just thinking about it is whoa

i mean fuck, basically if you go into one of those things you fast forward to the end of the universe

so like what happens to the black hole from your pov, just it just evaporate instantly?

>>	Anonymous Thu Jul 23 10:36:46 2015 No.7415680 >>7415677 *does it just

Anonymous Thu Jul 23 11:02:55 2015 No.7415737

>>7415656
>Imagine they are falling into the black hole, while watching a clock in the distance. What does the distant clock read when they reach the event horizon? It seems it would have an infinite value.

From the POV of the person falling in to the black hole, wouldn't the clock in the distance appear to be moving away at near light speed, and thus slowing down? Then at some point where the clock looks to have stopped, he/she passes the event horizon at what they perceive to be a 'normal' speed.

>>	Anonymous Thu Jul 23 11:05:19 2015 No.7415744 >>7415680 Fuck my shit up

Anonymous Thu Jul 23 11:28:14 2015 No.7415781

>>7415306
>I have no in depth understanding of the topic, but you seem to be intentionally ignoring the OP's point just because he made a fairly small error.
"I don't understand the topic but I will talk as if I do anyway". Shut the fuck up.

>I believe the idea behind it is that there are no real implications to it crossing the event horizon in its own finite time.
Well that's wrong.

>After all, for the entirety of its existence to the outside observer, the matter would exist in an infinitely dense shell on the event horizon. This would also play into any interactions that it has with the outside universe.
Depends on what coordinate system you use! Jesus Fucking Tapdancing Christ, why do I have to keep repeating this over and over? Learn general relativity or get the fuck out of this thread.

>>	Anonymous Thu Jul 23 11:51:41 2015 No.7415824 >>7415656 >What does the distant clock read when they reach the event horizon? It seems it would have an infinite value. No, see >>7415161.

>>	Anonymous Thu Jul 23 11:57:54 2015 No.7415836 >>7415677 See >>7415161; what you thought you knew is wrong.

Anonymous Thu Jul 23 12:32:35 2015 No.7416018

https://www.newscientist.com/article/dn25472-turbulent-black-holes-grow-fractal-skins-as-they-feed/

>“We showed that when you throw stuff into a black hole, the surface of the black hole responds like a fluid – and in particular, it can become turbulent”

Is it the matter that's stuck at the event horizon in the outside observer's perspective that is going turbulent?

>>	Anonymous Thu Jul 23 13:47:39 2015 No.7416183 >>7416018 No, I'm pretty sure they're talking about the geometry of the event horizon.

>>	Anonymous Thu Jul 23 14:16:48 2015 No.7416228 >>7413937 >there is no matter in existence that has ever crossed an event horizon. that is the point of my argument. And, it never will. The universe will end before the matter has a chance to cross the event horizon.

>>	Anonymous Thu Jul 23 14:53:12 2015 No.7416316 could black holes just be lack of space?

Anonymous Thu Jul 23 16:29:23 2015 No.7416550

>>7415781
I have a disclaimer because I'm not an expert in the field, but I knew what the OP meant when you seemed not to. Calm down and try to participate without being a condescending prick. Sure, there may be a reference frame in which it can cross the event horizon, but what is the significance of that when the universe has ended 10x over before that has passed? If I take a snapshot of a black hole at any time in the next trillion years from my end, would any matter have crossed the event horizon?

Would the black hole not completely dissipate before any matter crossed the event horizon, or am I wrong about that? If I am wrong, what is the the correct way to view it?

Simple questions, simple answers. I'm not going to pull out a GR textbook because it has no significance to my field of study, but I am interested in the OP's question.

>>	Anonymous Thu Jul 23 17:57:02 2015 No.7416727 >>7416550 All matter would be converted to energy as it approached the event horizon.

Anonymous Thu Jul 23 18:36:38 2015 No.7416800
File: 75 KB, 421x568, figure1.png [View same] [iqdb] [saucenao] [google]

>>7416550
>Sure, there may be a reference frame in which it can cross the event horizon,
This isn't something relative. Either it crosses at some point in spacetime or it doesn't. As for reference frames, that's a special relativity concept. It applies only in an approximate sense, over limited regions of spacetime.

>but what is the significance of that
To the people inside, it won't have any effect. Someone falling in would care, though.

>when the universe has ended 10x over before that has passed
As was pointed out even in the post you responded to, whether that's true or not depends on the coordinate system you use.

BTW, the expansion of the universe is getting faster, so there is (to current knowledge) no indication that it will end.

>If I take a snapshot of a black hole at any time in the next trillion years from my end, would any matter have crossed the event horizon?
You would be taking the snapshot with light (or something of equal or lesser speed), which cannot escape the event horizon, so you would not see the matter cross.

>Would the black hole not completely dissipate before any matter crossed the event horizon, or am I wrong about that?
This is more controversial, and quantum mechanics may actually result in the old classical (meaning not quantum mechanical) understanding of black holes being overturned. But as I understand it, the traditional semi-classical model is that it dissipates after the matter falls in (pic related). Note that there's still no way for an outside observer to see anything fall through the horizon, or anything beyond that.

>>	Anonymous Thu Jul 23 18:39:23 2015 No.7416805 >>7411764 If black holes can slow down time, can we use it somehow to travel to future?

>>	Anonymous Thu Jul 23 18:41:09 2015 No.7416809 >>7416805 Sure, but you can do it easier using the ship you'd need to get there.

>>	Anonymous Thu Jul 23 19:12:47 2015 No.7416870 >>7416805 Time travel to the future is easy as shit, no one cares about that.

>>	Anonymous Fri Jul 24 21:18:35 2015 No.7419037 >>7411764 Ok one thing I don't understand is rotating black holes. How can it be rotating if time stops at the event horizon?

>>	Anonymous Fri Jul 24 22:23:58 2015 No.7419129 >>7419037 It's basically the space rotating. The matter that formed the black hole was rotating, but after it fell through the event horizon, it doesn't affect the outside anymore.

>>	Anonymous Sat Jul 25 18:30:13 2015 No.7420584 File: 15 KB, 240x240, 1365718831562.png [View same] [iqdb] [saucenao] [google] >>7419037 The TL;DR of it poster is that movement doesn't necessarily imply time, if you move faster than a plank scale you're no longer moving, you're warping

>>	Anonymous Sat Jul 25 19:14:56 2015 No.7420693 >>7414135 >can i learn about falling in? >not from OP

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/sci/ - Science & Math