My thought experiment pertained to what happened to a collapsing star after it falls below its Scwhartzchild radius, because as far as I know, there’s no force or quantum mechanical principle to stop the collapse, but we can’t exactly say that all the matter falls into an infinitely-dense point of zero dimensions at the singularity. It may uncover one of the inequalities of QM and GR that keep us from finding the theory that connects the two.
To be fair, physics as a whole kind of starts stammering nervously when you ask it to accurately describe something with the mass of a star compressed into the space typically reserved for particles and assorted other atomic debris. It does make for a fascinating field of study, though.
@Nittany Discord
Well, the equations for a particle’s trajectory does actually reach the singularity in a finite (often really short) time, and it can’t stop any more than you can reverse time, so I can’t imagine there’s much to stop it.
I’m not afraid of calculus. I saw it every day in college and grad school, but Einstein’s equations are 4D tensor math based on the square of infinitesimals. It’s more exciting than scary to me to think about how those equations describe the really tiny bending of space and time around matter and energy.
But I’ll definitely take a look at the simplified stuff.
My thought experiment pertained to what happened to a collapsing star after it falls below its Scwhartzchild radius, because as far as I know, there’s no force or quantum mechanical principle to stop the collapse, but we can’t exactly say that all the matter falls into an infinitely-dense point of zero dimensions at the singularity. It may uncover one of the inequalities of QM and GR that keep us from finding the theory that connects the two.
@Nittany Discord
Once you’re in the event horizon, stopping your plunge to the singularity is paramount to stopping, or even going backwards in time. So unless any physical process can reverse time, it can’t stop the collapse.
So far, no such phenomenon have been observed, barring some interpretations of quantum mechanics - but those don’t work in a way that would prevent the collapse into a singularity (lol, this quantum phenomenon actually has to do with quantum state “collapse”, so same word, but entirely different meaning from the “collapse” of material into a singularity).
How much do you know already?
I started with Brian Greene’s books, “The Fabric of the Cosmos,” “The Hidden Reality,” and “The Elegant Universe.” The first one isn’t actually the first one he wrote, but, before I even knew anything about GR (other than it was a ludicrously complex theory of gravity that made such small corrections to Newton’s theories that Newton’s gravity is still good enough to colonize Mars, or even Pluto with), the idea of spacetime itself being some sort of fabric of reality fascinated me enough that I just devoured that book.
Next was Kip Thorne’s Black Holes and Time Warps. It’s a bit more technical, but still doesn’t go into the math.
Now, when it came down to chomping on the simpler math I got a textbook. It’s just some of the metrics of GR, rather than the entire theory.
From what I’ve gathered, typically what a physicist will do (knowing the full theory) is plugging in an arrangement of matter/energy, work the equations, and out comes a metric, then analyze the metric.
This book covers the “analyze the metric” part, as well as the necessary principles of GR required to do so. It covers the Schwarzchild - black hole - metric, and even touches on the Kerr spinning black hole metric near the end.
It’s actually rather surprising in that you can cover most of GR this way. It talks about geodesics, time dilation, orbits and how they differ from Newton’s orbits - all that good stuff, and it only requires algebra, and only touches on some calculus every so often. For the most part, you can just think of “dt” as a different name for a time interval :P Link to that book.
I think a really neat thing they did when making this, is they let students read it, bring up all kinds of questions and “wait a second!…” types of thoughts, then they edited the book to include them in little notes. The book even has problems to work, to boot! I loved that part of it.
Now, what I’m doing now, though, is watching the Stanford lectures on General Relativity. I’m only on 4/10, but this really gets into the meat of the theory. They’re freely available on Youtube, but I’m having a little difficulty keeping up with the math since I haven’t covered multivariable calculus yet, but I get most of it, and all of the qualitative parts, having only covered Linear Algebra (matrices, vectors, etc.).
@Cirrus Light
I actually find GR and black holes quite fascinating, and wonder if I could wrap my head around the equations of GR.
There’s also the question of what happens to matter in a black hole, and if there’s anything beyond neutron degeneracy pressure to prevent all matter from falling into a point (bar some freezing of space-time).
@runesorcerer
Honestly, I’m a bit of a fan of black hole cosmology - it’s established and respectable physics, but it’s not a particularly big theory, but it’s a cosmological theory about the nature of the universe.
I’ve got a few ideas I’d like to research more, but there’s some really fascinating implications about the singularity, specifically, and even more so about the nature of space and time. Nothing that special relativity doesn’t already say, but something that few people really internalize.
If you thought this was whacky, things get a lot more crazy when you actually cross the black hole, and I’m actually thinking of maybe publishing some of my own observations on the matter that would probably apply to not only Schwarzchild black holes, but Kerr (spinning) and Kerr-Newman (charged, spinning), as well. Not sure if it applies to Reissner-Nordstrom’s solution or not (charged, not spinning).
Hhhmmm, actualy, dang, I really need to look into those metrics. I think that they may have a rather interesting property I’ve been wondering about…
I think black holes are things too. However, when I think about the singularity, I think about it as the drain of a bathtub.
The thing is, thinking about the entire black hole as the drain makes sense too, at least for me, because while it could still be matter, it could also be where matter goes to.
Also, I think “obligatory pony” is for things that are posted here, with a pony thrown in so that it meets the rules. Technically, that’s against the rules.
But the pony wasn’t thrown in here to make it meet the rules and able to be posted here - instead, it meets the rules and was posted here because of the ponies that were already there, so It’s good to stay, I say, and that tag doesn’t belong.
So he got it. The only thing is I might say that Black Holes are things, they’re just constructs made entirely of spacetime, but that comes down to: do you call spacetime itself a “thing”? I’d say, that because it has properties (namely, curvature), it does classify as a “thing”, but that’s more a philosophical question than a physical one.
I’m just jealous someone beat me to using ponies in physics XP
This video is what got me to subsribe to this channel. Even disregarding the ponies, it does a great job of explaining the time dilating effects of intense gravitational fields.
Why aren’t Rainbow Dash and fluttershy wearing space suits? And why are they flapping their wings in a vacuum where their wings wouldn’t do anything? Why the hell do I care?
Yep.
Oh right, been a long time since I saw it - so the monkey is the one falling in?
It’s okay. Fluttershy is hovering over the black hole. She has some major wingpower.
Edited
Try Baez’s relativity tutorial. It’s got several levels of explanations, from verbal to visual to calculational.
http://math.ucr.edu/home/baez/gr/
Well, the equations for a particle’s trajectory does actually reach the singularity in a finite (often really short) time, and it can’t stop any more than you can reverse time, so I can’t imagine there’s much to stop it.
Also, more on black holes, a really neat little site I found.
Awesome.
I’m not afraid of calculus. I saw it every day in college and grad school, but Einstein’s equations are 4D tensor math based on the square of infinitesimals. It’s more exciting than scary to me to think about how those equations describe the really tiny bending of space and time around matter and energy.
But I’ll definitely take a look at the simplified stuff.
My thought experiment pertained to what happened to a collapsing star after it falls below its Scwhartzchild radius, because as far as I know, there’s no force or quantum mechanical principle to stop the collapse, but we can’t exactly say that all the matter falls into an infinitely-dense point of zero dimensions at the singularity. It may uncover one of the inequalities of QM and GR that keep us from finding the theory that connects the two.
Once you’re in the event horizon, stopping your plunge to the singularity is paramount to stopping, or even going backwards in time. So unless any physical process can reverse time, it can’t stop the collapse.
So far, no such phenomenon have been observed, barring some interpretations of quantum mechanics - but those don’t work in a way that would prevent the collapse into a singularity (lol, this quantum phenomenon actually has to do with quantum state “collapse”, so same word, but entirely different meaning from the “collapse” of material into a singularity).
How much do you know already?
I started with Brian Greene’s books, “The Fabric of the Cosmos,” “The Hidden Reality,” and “The Elegant Universe.” The first one isn’t actually the first one he wrote, but, before I even knew anything about GR (other than it was a ludicrously complex theory of gravity that made such small corrections to Newton’s theories that Newton’s gravity is still good enough to colonize Mars, or even Pluto with), the idea of spacetime itself being some sort of fabric of reality fascinated me enough that I just devoured that book.
Next was Kip Thorne’s Black Holes and Time Warps. It’s a bit more technical, but still doesn’t go into the math.
Now, when it came down to chomping on the simpler math I got a textbook. It’s just some of the metrics of GR, rather than the entire theory.
From what I’ve gathered, typically what a physicist will do (knowing the full theory) is plugging in an arrangement of matter/energy, work the equations, and out comes a metric, then analyze the metric.
This book covers the “analyze the metric” part, as well as the necessary principles of GR required to do so. It covers the Schwarzchild - black hole - metric, and even touches on the Kerr spinning black hole metric near the end.
It’s actually rather surprising in that you can cover most of GR this way. It talks about geodesics, time dilation, orbits and how they differ from Newton’s orbits - all that good stuff, and it only requires algebra, and only touches on some calculus every so often. For the most part, you can just think of “dt” as a different name for a time interval :P
Link to that book.
I think a really neat thing they did when making this, is they let students read it, bring up all kinds of questions and “wait a second!…” types of thoughts, then they edited the book to include them in little notes. The book even has problems to work, to boot! I loved that part of it.
Now, what I’m doing now, though, is watching the Stanford lectures on General Relativity. I’m only on 4/10, but this really gets into the meat of the theory. They’re freely available on Youtube, but I’m having a little difficulty keeping up with the math since I haven’t covered multivariable calculus yet, but I get most of it, and all of the qualitative parts, having only covered Linear Algebra (matrices, vectors, etc.).
I actually find GR and black holes quite fascinating, and wonder if I could wrap my head around the equations of GR.
There’s also the question of what happens to matter in a black hole, and if there’s anything beyond neutron degeneracy pressure to prevent all matter from falling into a point (bar some freezing of space-time).
Source
Honestly, I’m a bit of a fan of black hole cosmology - it’s established and respectable physics, but it’s not a particularly big theory, but it’s a cosmological theory about the nature of the universe.
I’ve got a few ideas I’d like to research more, but there’s some really fascinating implications about the singularity, specifically, and even more so about the nature of space and time. Nothing that special relativity doesn’t already say, but something that few people really internalize.
If you thought this was whacky, things get a lot more crazy when you actually cross the black hole, and I’m actually thinking of maybe publishing some of my own observations on the matter that would probably apply to not only Schwarzchild black holes, but Kerr (spinning) and Kerr-Newman (charged, spinning), as well. Not sure if it applies to Reissner-Nordstrom’s solution or not (charged, not spinning).
Hhhmmm, actualy, dang, I really need to look into those metrics. I think that they may have a rather interesting property I’ve been wondering about…
I think black holes are things too. However, when I think about the singularity, I think about it as the drain of a bathtub.
The thing is, thinking about the entire black hole as the drain makes sense too, at least for me, because while it could still be matter, it could also be where matter goes to.
But that’s just my opinion tho.
But the pony wasn’t thrown in here to make it meet the rules and able to be posted here - instead, it meets the rules and was posted here because of the ponies that were already there, so It’s good to stay, I say, and that tag doesn’t belong.
I one being about the speed of light, or that’s what I , please excuse my memory span of a dead fish.
I’m just jealous someone beat me to using ponies in physics XP
lol. I’ve seriously considered doing educational stuff on Deviantart using ponies :q