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Eldar Black Holes

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Re: Eldar Black Holes

#71

Post by make3 »

grondilu wrote: post #8

There is a fascinating PBS Space Time video[1] about black holes that questions the very existence of whatever is "inside" a black hole. They point out that as you approach a black hole, your proper time is advancing slower and slower when compared to an observer located far away from the black hole (like us, on Earth). That means that from the point of view of this far observer, nothing happens inside a black hole u…

not an physicist, but from the point of view of the thing going on the black whole, time still goes on smoothly. My understanding is that the inside of the black whole becomes like a new universe, effectively cut from the previous one from the perspective of causality

Re: Eldar Black Holes

#72

Post by zaphod12 »

pavel_lishin wrote: post #62
jcadam wrote: post #45

Reminds me a bit of the old short story The Crystal Spheres. In that universe, once a civilization had attained a certain level of advancement, they intentionally migrated to a black hole to await the arrival of others (the idea being that all advanced civilizations in the universe were separated by so much time , that they suffered from a sort of loneliness). https://en.wikipedia.org/wiki/The_Crystal_Spheres

There's another book whose name is on the tip of my tongue that has a similar premise, except the planet instead of the entire system is encased in a sort of time-dilation field. Naturally, humanity thinks it's an attack.

I believe you're thinking of Spin by Robert Charles Winston.

Really good book

Re: Eldar Black Holes

#73

Post by v_lisivka »

make3 wrote: post #69
olegkikin wrote: post #12

Earlier quoted context omitted.

That's the thing that never made sense to me about the black holes. The closer you are to the event horizon, the faster the time passes for the universe around you. So reaching the event horizon should take infinite amount of the "outside time", so right before you reach the horizon, you should see the whole future of the universe, including its end, if there's any. So how do black holes gain any mass then?

[Deleted]

so, because black hole rotates, at some point in far future, speed of the shell will cross speed of light just because of geometry.

Re: Eldar Black Holes

#74

Post by whatshisface »

dictum wrote: post #22
whatshisface wrote: post #20

Earlier quoted context omitted.

The only well-traveled path to understanding physics starts at "highschooler with a lot of confidence in their math skills," and it takes four years minimum. Anything else is going to be a long shot, just by virtue of the fact that nobody's doing it (for the most part). Nobody has ever discovered a way to truthfully map physics concepts into English sentences that you can understand without having to have explored th…

Concurrently, every attempt to map physics concepts into English is met by a barrage of "well, actually".

That's because the mappings always fail - not so much a concurrent thing as a consequence. (For comparison, you can say everything about Roman troop organization in English, because that's native to how the information exists in the first place. You won't get any "well, actually" about the size of a legion, because it involves words and concepts that everyone already knows.)

Re: Eldar Black Holes

#75

Post by solipsism »

pavel_lishin wrote: post #62
jcadam wrote: post #45

Reminds me a bit of the old short story The Crystal Spheres. In that universe, once a civilization had attained a certain level of advancement, they intentionally migrated to a black hole to await the arrival of others (the idea being that all advanced civilizations in the universe were separated by so much time , that they suffered from a sort of loneliness). https://en.wikipedia.org/wiki/The_Crystal_Spheres

There's another book whose name is on the tip of my tongue that has a similar premise, except the planet instead of the entire system is encased in a sort of time-dilation field. Naturally, humanity thinks it's an attack.

Sounds like Spin by Robert Charles Wilson.

Re: Eldar Black Holes

#76

Post by v_lisivka »

grondilu wrote: post #8

There is a fascinating PBS Space Time video[1] about black holes that questions the very existence of whatever is "inside" a black hole. They point out that as you approach a black hole, your proper time is advancing slower and slower when compared to an observer located far away from the black hole (like us, on Earth). That means that from the point of view of this far observer, nothing happens inside a black hole u…

But black hole has center, where gravity forces from shell negates each other, which has zero gravity, thus normal speed.

Re: Eldar Black Holes

#77

Post by olegkikin »

IntronExon wrote: post #67
olegkikin wrote: post #65

Earlier quoted context omitted.

But from our perspective, the outside observers, why do black holes gain mass? It would take an infinite amount of time from our perspective for any mass to even touch the event horizon.

At this point a few issues arise. The first is that what you’re describing is a feature of the Schwarzschild metric, which applies to a model black hole, which is time-independent and eternal. There is no particular reason to believe that this accurately describes black holes in nature. For example this metric can not describe the merger of two black holes, but we now have observational evidence that this does indeed…

> The crew of a 99.9% lightspeed ship doesn’t experience time dilation until they return home.

That's not true. They see the universe around them moving much faster.

Time dilation has nothing to do with "returning home".

Re: Eldar Black Holes

#78

Post by IntronExon »

grondilu wrote: post #19
olegkikin wrote: post #12

Earlier quoted context omitted.

That's the thing that never made sense to me about the black holes. The closer you are to the event horizon, the faster the time passes for the universe around you. So reaching the event horizon should take infinite amount of the "outside time", so right before you reach the horizon, you should see the whole future of the universe, including its end, if there's any. So how do black holes gain any mass then?

> So how do black holes gain any mass then? Well, from our point of view all incoming mass gets stuck very close to the event horizon. That's not too surprising considering the amount of information of a black hole is proportional to its surface area. So from a far away observer a black hole is more like a sticky sphere than an hollow ball.

What is important to remember is thst our point of view is not special or “right” in any way. There is a difference between our observation of a process like matter falling into a black hole, and the reality of it. Black holes do “eat” and grow, and that occurs despite the intense time dilation near their surface. The light which returns to us will be redshifted to black, and we won’t see the final event, but it does happen in its own proper time, in finite time. When black holes merge we can detect their gravitational waves, evidence that black holes are not “frozen” in reality.

It is also important to distinguish between the implications of a model black hole formed from the uniform collapse of a perfectly spherical dust cloud, from infinity, in an otherwise empty universe, with no charge or angular momentum, from what happens in nature.

Re: Eldar Black Holes

#79

Post by dcow »

krapp wrote: post #26
pwaai wrote: post #15

what if our universe is expanding because there are other bubbles of universes that pull in all directions? what if Buddha was right in that there are thousand fold universe systems each with their own unique civilizations? If there are blackholes older than the universe itself, what if that suggested the universe was cyclical and that we may be in some gazillion-th iteration? what if big bang was just a universe eve…

>What about the strange UFO occurences that pentagon acknowledged, are we getting visits from aliens within our universe or from another universe? The Pentagon has never acknowledged the existence of extraterrestrial craft, or of UFOs as being anything but hoaxes and misidentified, mundane phenomena. >but how could Buddha have known that blackholes existed? He didn't, any more than the Norse knew that wormholes exist…

I agree, but remember our science today will look like Norse mythology in 1000 years too.

Re: Eldar Black Holes

#80

Post by visarga »

dustingetz wrote: post #57
grondilu wrote: post #8

There is a fascinating PBS Space Time video[1] about black holes that questions the very existence of whatever is "inside" a black hole. They point out that as you approach a black hole, your proper time is advancing slower and slower when compared to an observer located far away from the black hole (like us, on Earth). That means that from the point of view of this far observer, nothing happens inside a black hole u…

Between reality and maths, the maths are the more fundamental thing that is used to explain reality. What you call reality is just some circumstances that your brain got used to.

On the contrary, maths are just approximations of reality, not something fundamental to it.
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