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Eldar Black Holes

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Re: Eldar Black Holes

#21

Post by grondilu »

wcarss wrote: post #18
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…

off-topic a bit: does anyone have suggestions for paths for the layperson toward being able to reason and intuit about this stuff at one level beyond pop physics claptrap? I have heard "the theoretical minimum" suggested in the past, but I haven't heard from anyone who has actually used it to go from zero to say, general relativity, only people who think it sounds good. It also seems like a steep investment -- I just…

> has an infinite number of different stupid questions

I think teachers often welcome any question. On coursera for instance teachers are usually available to answer students (via a mail-like interface though, don't expect to chat with them via Skype or anything). There are several courses on general relativity.

Re: Eldar Black Holes

#22

Post by dictum »

whatshisface wrote: post #20
wcarss wrote: post #18

Earlier quoted context omitted.

off-topic a bit: does anyone have suggestions for paths for the layperson toward being able to reason and intuit about this stuff at one level beyond pop physics claptrap? I have heard "the theoretical minimum" suggested in the past, but I haven't heard from anyone who has actually used it to go from zero to say, general relativity, only people who think it sounds good. It also seems like a steep investment -- I just…

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".

Re: Eldar Black Holes

#23

Post by metaobject »

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.

Doesn't the surface area increase as the BH takes on more mass?

Re: Eldar Black Holes

#24

Post by JumpCrisscross »

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…

> no way to find these answers

Yes there are. Answering such questions is why physicists are searching so hard for a unified micro/macro theory. Black holes are both quantum mechanical (at their singularities) and relativistic.

> how could Buddha have known that blackholes existed?

He didn’t.

Re: Eldar Black Holes

#25

Post by fao_ »

wcarss wrote: post #18
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…

off-topic a bit: does anyone have suggestions for paths for the layperson toward being able to reason and intuit about this stuff at one level beyond pop physics claptrap? I have heard "the theoretical minimum" suggested in the past, but I haven't heard from anyone who has actually used it to go from zero to say, general relativity, only people who think it sounds good. It also seems like a steep investment -- I just…

Feynman's lectures of physics are good for layman explanations, however they quickly feel lacking without the maths background, which you can fill in with The Theoretical Minimum. There's actually a video lecture series of the Theoretical Minimum series that you might find more approachable, that is if you haven't heard of it: https://www.youtube.com/view_play_list?p=189C0DCE90CB6D81 (Here for the general relativity playlist: https://www.youtube.com/view_play_list?p=6C8BDEEBA6BDC78D, and here for the full list of playlists: http://theoreticalminimum.com/courses/archive)

You say you haven't heard from anyone who has used it to go from zero to say, general relativity. You might want to look into the adult alumni of the class.

EDIT: You might also find another HN post interesting, it's currently at the top of HN classic: "Learning classical mechanics through Haskell", here: https://news.ycombinator.com/item?id=16453192

(And a direct link to "Classical Mechanics via Scheme", https://mitpress.mit.edu/sites/default/files/titles/content/...)

Re: Eldar Black Holes

#26

Post by krapp »

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 existed when describing the Bifrost bridge or the World Tree. Reading modern scientific meaning into ancient religious ideas is a common way to attempt to validate religion, but doing so does a disservice both to the religion and to science.

The Buddha may have had many insights, but none of them involved the relationship between spacetime and gravity.

Re: Eldar Black Holes

#27

Post by grondilu »

metaobject wrote: post #23
grondilu wrote: post #19

Earlier quoted context omitted.

> 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.

Doesn't the surface area increase as the BH takes on more mass?

Yes, but the mass does not have to cross the event horizon for that, does it?

At that point we probably can't tell more without diving into the math, and it's beyond my abilities. Yet the gross idea does not seem absurd to me.

Re: Eldar Black Holes

#28

Post by heavenlyblue »

garmaine wrote: post #10
LoSboccacc wrote: post #4

Wonder if they also explored the possibility that we are in a black hole and the universe structure is recursive. Maybe the background radiation is the part of the hawking radiation that falls inward. And we perceive it infinite but it’s the dilatated space between the hevent horizon and the naked singularity at the center. And the big bang was the supernova that left the black hole. Trippinng!

We are in a black hole. The event horizon of the entire universe is on the same order as the observable universe. We are inside the black hole of the universe.

What?

Re: Eldar Black Holes

#30

Post by IntronExon »

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…

This strikes me as an issue between understanding these events from the point of view of an external observer, and a test particle or person falling into the hole. From the POV of the observer, your statements are largely accurate, for certain types of universes. For the test particle, there is no freeze frame, all proceeds normally.

The key is the Relative in Relativity.

Truthfully, there is no clear answer as to what a black hole has for an interior, or if it really has one. Holographic theorists would argue that the event horizon is the black hole, String theorists would argue that there is an interior, but no singularity. We just don’t know.

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