🧵 Why can't light escape?
Anonymous at Thu, 7 Mar 2024 23:04:32 UTC No. 16061988
Dumb question: I was told that black holes can have an electric charge because the electric field can extend from inside the black hole to outside the black hole. I would also think that a magnetic field can extend from inside to outside as well. So if electric and magnetic fields can extend outside a black hole, why can't the electric and magnetic fields of electromagnetic radiation extend from inside to outside a black hole?
Anonymous at Thu, 7 Mar 2024 23:06:24 UTC No. 16061991
>>16061988
Read landau lifshitz vol 2
Anonymous at Thu, 7 Mar 2024 23:08:24 UTC No. 16061997
>>16061991
I found an online copy. Which page is most pertinent?
Anonymous at Thu, 7 Mar 2024 23:11:32 UTC No. 16062002
It's all very simple. Space is expanding inside a black hole faster than light.
Anonymous at Thu, 7 Mar 2024 23:13:57 UTC No. 16062005
>>16062002
How did the "information" about an electric charge being inside the black hole overcome this?
Anonymous at Thu, 7 Mar 2024 23:14:43 UTC No. 16062007
>>16061988
it can
Anonymous at Thu, 7 Mar 2024 23:33:01 UTC No. 16062033
>>16062005
It's all very simple. There is only one electron.
Anonymous at Thu, 7 Mar 2024 23:38:08 UTC No. 16062040
>>16061988
The whole point of the event horizon is all timelike or lightlike worldlines that start on one side of the horizon can never leave. But field lines extend in spacelike directions, so there is no issue.
Anonymous at Thu, 7 Mar 2024 23:53:33 UTC No. 16062047
what is it about black holes that makes them the number one most popular popsci topic of discussion amongst the brainlet soience fangoys?
is it the comic bookish aspects of the spectacular, unrealistic and completely non disprovable conjectures which go along with the topic that make black holes so popular amongst the scientist posers and wannabes?
Anonymous at Fri, 8 Mar 2024 00:16:20 UTC No. 16062076
>>16062040
>field lines extend in spacelike directions
Isn't light an excitation of two fields? It doesn't experience time, only space, so I hear.
>The whole point
That's basically what I'm asking. The fields extend out past the event horizon, but excitations of the field can't?
Anonymous at Fri, 8 Mar 2024 00:28:53 UTC No. 16062085
>>16061991
>Read jewish schizophrenia vol 2
Anonymous at Fri, 8 Mar 2024 00:29:43 UTC No. 16062086
>>16062047
Cause they're unknown and mysterious, why does this upset an autist like you?
Anonymous at Fri, 8 Mar 2024 01:07:15 UTC No. 16062130
>>16061988
Light can escape Roy Kerr proved it last month
Penrose and Hawking are frauds
Anonymous at Fri, 8 Mar 2024 01:29:58 UTC No. 16062147
>>16061988
isnt it the same as with gravity? gravitational waves cant leave a black hole just like electromagnetic waves, but a black hole still has gravity, because the curvature remains
Anonymous at Fri, 8 Mar 2024 02:58:50 UTC No. 16062198
Anonymous at Fri, 8 Mar 2024 03:40:17 UTC No. 16062246
>>16061988
>in the middle of a black hole is a one dimensional point with a huge mass at infinite density
How did they get otherwise intelligent people to actually believe this?
Anonymous at Fri, 8 Mar 2024 04:31:05 UTC No. 16062297
>>16062246
It’s pretty much accepted to be a shitty/faulty prediction at this point.
Anonymous at Fri, 8 Mar 2024 06:21:37 UTC No. 16062408
>>16061988
Serious answer:
>Within the event horizon of a black hole space is curved to the point where all paths that light might take to exit the event horizon point back inside the event horizon. This is the reason why light cannot escape a black hole. Another way to look at it is that the escape velocity from the event horizon of a black hole is faster than the speed of light. Since nothing can travel faster than the speed of light, nothing escapes the event horizon of a black hole.
Anonymous at Fri, 8 Mar 2024 07:09:36 UTC No. 16062451
>>16062085
germany lost
Anonymous at Fri, 8 Mar 2024 07:37:24 UTC No. 16062485
>>16062047
Its where all the effects of GR are most prominent and reach their limit. The same particle physics focus on sub-atomic particles and quarks, and not molecules.
Anonymous at Fri, 8 Mar 2024 14:16:15 UTC No. 16062776
>>16061988
It is wrong to think of EM-fields and gravity extending out from inside the blackhole because as you have noticed, nothing once it crosses the event horizon can affect the outside world. Instead, because of the extreme time dilation, external observers will never seen any matter fall into the blackhole. It can be thought of as a shell of mass and charge at the event horizon, frozen in time.
Anonymous at Fri, 8 Mar 2024 14:27:52 UTC No. 16062794
>>16062047
we have jungle fever
Anonymous at Fri, 8 Mar 2024 15:51:55 UTC No. 16062922
>>16062076
Say you perturb the electric and magnetic fields inside the horizon. That perturbation spreads out at the speed of light just like in flat space. In other words a point on the front between the old static field lines and the spreading region carrying information about the perturbation is following a lightlike trajectory in spacetime. All such trajectories can never leave the horizon.
If it still doesn't make sense to you, make sure you understand the flat case first. If you have non zero net charge somewhere, there must be field lines arbitrarily far away due to Gauss's law. But those field lines aren't giving you instantaneous information about the charges. If you move the configuration of charges, the fields will change, but the change in fields propagates out at the speed of light and isn't instantaneous
🗑️ Anonymous at Fri, 8 Mar 2024 15:53:10 UTC No. 16062924
>>16062776
Stop giving false information. A charged black hole has an electric field
Anonymous at Fri, 8 Mar 2024 16:07:52 UTC No. 16062950
>>16062076
Maybe the following will help you understand (or maybe not). The ordinary coordinate systems for a black hole has the event horizon be a static sphere at some radius, but actually this description of a black hole is not suitable for describing the interior. Many coordinate systems that extend to the interior of the blackhole describe the event horizon as moving outward at the speed of light. The reason information can not leave the horizon is because it can never catch up. This sounds weird compared to how black holes are usually described in pop sci, but this is just a change of coordinates and even in the old coordinates the event horizon is a "null surface," which means a surface moving at the speed of light.
In these non-static coordinates the situation is clear. Field lines can extend past the horizon because they are already there extending to spatial infinity. A perturbation of the field lines can't leave the horizon because it travels at the speed of light and can't catch the horizon (which is also moving at the speed of light)
Anonymous at Sat, 9 Mar 2024 03:08:17 UTC No. 16064208
>>16062451
>barbarians won, therefore they're right
OGA OGA