Eldar Black Holes • Hacker News Board

Re: Eldar Black Holes

#11

Post by hliyan » Sat, Feb 24, 2018, 3:32 PM UTC

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…

I imagine this as time asymptotically slowing as you approach the singularity so that the singularity is forever stuck at the time of the supernova explosion that gave birth to it. You can never reach it because you and your movements too, slow down the closer you get. Is that correct?

Re: Eldar Black Holes

#12

Post by olegkikin » Sat, Feb 24, 2018, 3:34 PM UTC

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…

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?

Re: Eldar Black Holes

#13

Post by grondilu » Sat, Feb 24, 2018, 3:37 PM UTC

hliyan wrote: post #11

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…

I imagine this as time asymptotically slowing as you approach the singularity so that the singularity is forever stuck at the time of the supernova explosion that gave birth to it. You can never reach it because you and your movements too, slow down the closer you get. Is that correct?

A traveler can reach it all right, but only from his own point of view. From the point of view of almost everyone else in the Universe, including us on Earth, it will never ever reach it. It's like the traveler has jumped into an other universe "located" in an infinitely distant future.

Re: Eldar Black Holes

#14

Post by tziki » Sat, Feb 24, 2018, 3:38 PM UTC

This was a major theme in the 'three body problem' book series.

Re: Eldar Black Holes

#15

Post by pwaai » Sat, Feb 24, 2018, 3:40 PM UTC

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 eventually being consumed by a monstrous blackhole that collapses itself?

What about the strange UFO occurences that pentagon acknowledged, are we getting visits from aliens within our universe or from another universe? Have they figured out how to travel between multi-verse, that is if you believe in it?

No proof, no way to find these answers but it really makes me wonder, especially when particles behave strangely like being coupled regardless of distance...but how could Buddha have known that blackholes existed?

https://www.reddit.com/r/Buddhism/comments/6o8zmg/the_buddha...

Anyways, just some things to ponder and gawk about...

Re: Eldar Black Holes

#16

Post by grondilu » Sat, Feb 24, 2018, 3:41 PM UTC

garmaine wrote: post #9

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…

No it doesn’t make sense. That explanation is privledging remote observers frames of reference to “explain” what happens in another frame of reference. That’s a violation of our modern understanding of physics.

It's not "privileging" any thing in the sense that it does not claim one point of view is more valid than the other.

It's just that one of these point of view is ours, and from this point of view, the other point of view does not correspond to any event that will actually happen, like ever.

In other words, the "happening of events" is a relative concept. Just like simultaneity. Not only two events can happen at the same time or not depending on who is observing them, but the very happening of an event can also depend on who is observing (or not observing) it.

That "happening of events" is very close to a definition one can give to the concept of reality. So one might conclude that reality is a relative concept.

Re: Eldar Black Holes

#17

Post by phamilton » Sat, Feb 24, 2018, 3:43 PM UTC

olegkikin wrote: post #12

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…

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?

Wouldn't it just depend on your definition of the area of the black hole? By your logic, I certainly agree that black holes having mass beyond their event horizon is an impossibility from an observation perspective, but how far outside the event horizon do we include in our definition of a black hole? Far enough out, we could certainly observe them gaining mass.

Re: Eldar Black Holes

#18

Post by wcarss » Sat, Feb 24, 2018, 3:46 PM UTC

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 want to have a decent enough grasp to separate sense from nonsense and hold a picture in my mind.

One related thing I have wished existed was a good place to ask questions about and discuss topics like this while learning them, but it seems like in theoretical physics, everyone (including myself) has an infinite number of different stupid questions and misconceptions, to the point that we drown each other out, and answers to our questions often have little cross-applicability.

So, would love ideas for either!

Re: Eldar Black Holes

#19

Post by grondilu » Sat, Feb 24, 2018, 3:47 PM UTC

olegkikin wrote: post #12

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…

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.

Re: Eldar Black Holes

#20

Post by whatshisface » Sat, Feb 24, 2018, 3:53 PM UTC

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…

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 the entire definition tree.