[VIDEO]Travel inside a black hole !

[SolarLiner]

I saw recently a video from vsauce on Youtube, it was talking about black holes:
[ame=http://www.youtube.com/watch?v=3pAnRKD4raY]VSauce - Travel Inside a Black hole ![/ame]

Then I was a little time in google search ... Found this:
[ame="http://en.wikipedia.org/wiki/Einstein_ring"]Einstein ring - Wikipedia, the free encyclopedia[/ame]
http://www.spacetimetravel.org/expeditionsl/expeditionsl.html
http://casa.colorado.edu/~ajsh/approach.html
Then I saw the links in the vsauce video description ...

One of the source from above video:


And when searching the forums to know is this video were already posrted, I found this thread: Simple 2D black hole simulator

So I have to share you these things, and black holes are something magical for me (since they can compress light and time, and you have some "visual abberations" around it with the gravitational lensing ... They makes me dream ^^)

 

[Shadownailshot]

Everyone needs the ego boost of knowing they're the center of the universe.

 

[palebluevoice]

Infinite density? Seems legit...

 

[Artlav]

That reminds me of a thing i made a few years ago.
It could simulate wormhole travel and a black hole, interactive and visual.
http://www.orbiter-forum.com/showthread.php?p=165820&postcount=32
Enjoy, if it still works.

 

[Shadownailshot]

Infinite density? Seems legit...

Have you ever heard of the big bang? There's some theories that before the big bang, there was only a black hole. After all, it was said to be a point of "infinite density." Presumably this black hole was the result of a previous universe collapsing in on itself.

 

[jthill]

http://realtimerelativity.org/ might be relevant here.

 

[Quick_Nick]

I think "maximum density" makes much more sense than "infinite density".
Something infinitely dense ought to have infinite mass and exert infinite force on everything.
Something with a maximum of information per cubic planck length should be maximally dense, exert a large finite force, and grow outward as it accumulates more matter; like a black hole.
No doubt the big bang violates that though, without some relativity or something I don't understand. (not that the big bang needs physics as we know it)

 

[Shadownailshot]

I think "maximum density" makes much more sense than "infinite density".
Something infinitely dense ought to have infinite mass and exert infinite force on everything.
Something with a maximum of information per cubic planck length should be maximally dense, exert a large finite force, and grow outward as it accumulates more matter; like a black hole.
No doubt the big bang violates that though, without some relativity or something I don't understand. (not that the big bang needs physics as we know it)

Density is independent of mass, and vice versa. Mass is an amount, density is how "packed" that amount is. When they say infinite, it means to dense to be measured, or too dense to really matter how dense it is.

I've heard the word infinite used in other areas of physics before, such as talking about inter-galactic distances. "A galaxy infinitely distant." That statement really meant it was something like 100s of millions of ly away, but in practical terms, that's infinity.

 

[palebluevoice]

Density is independent of mass, and vice versa. Mass is an amount, density is how "packed" that amount is. When they say infinite, it means to dense to be measured, or too dense to really matter how dense it is.

I've heard the word infinite used in other areas of physics before, such as talking about inter-galactic distances. "A galaxy infinitely distant." That statement really meant it was something like 100s of millions of ly away, but in practical terms, that's infinity.

13.7 billion light years(I believe) is the farthest galaxy ever observed. 13.7*10^9000000000000^9000000000 isn't 1*10^-9000000000000000000000000000000% of infinity. Infinity doesn't mean too big to comprehend; can you really comprehend 10,000 M&Ms(not a container of M&Ms, not a pile with XYZ dimensions, but the same way you'd comprehend 3) Unless you have a different brain than me, you can't comprehend that. 10,000 M&Ms is not infinite in any terms.

I understand educators throw around infinity, in the same way that they teach that phases of the moon are based on its true anomaly, or you can't take the square root of a negative number; there's enough complicated material to learn, but there needs to be a footnoot sometimes.

 

[Shadownailshot]

13.7 billion light years(I believe) is the farthest galaxy ever observed. 13.7*10^9000000000000^9000000000 isn't 1*10^-9000000000000000000000000000000% of infinity. Infinity doesn't mean too big to comprehend; can you really comprehend 10,000 M&Ms(not a container of M&Ms, not a pile with XYZ dimensions, but the same way you'd comprehend 3) Unless you have a different brain than me, you can't comprehend that. 10,000 M&Ms is not infinite in any terms.

I understand educators throw around infinity, in the same way that they teach that phases of the moon are based on its true anomaly, or you can't take the square root of a negative number; there's enough complicated material to learn, but there needs to be a footnoot sometimes.

I'm just saying, it's expressed that way when it's so much or so far or so dense or so many that the number no longer matters in a practical sense. Such as the distance of that galaxy. Technically, it's gravity effects us, but the galaxy is so far away, the distance is actually irrelevant. Therefore it can be said to be an infinite distance away.

 

[Linguofreak]

I think "maximum density" makes much more sense than "infinite density".
Something infinitely dense ought to have infinite mass and exert infinite force on everything.

Nope. Infinite density just means "nonzero mass in zero volume".

If you have a mass of 1 Earth mass all concentrated at one point, you have infinite density at that point, but it's still 1 Earth mass, and the gravitational acceleration at any given radius is the same as the surface gravity for a 1 Earth mass sphere of that radius.

 

[Shadownailshot]

Nope. Infinite density just means "nonzero mass in zero volume".

If you have a mass of 1 Earth mass all concentrated at one point, you have infinite density at that point, but it's still 1 Earth mass, and the gravitational acceleration at any given radius is the same as the surface gravity for a 1 Earth mass sphere of that radius.

Well that makes more sense than what I was saying.

 

[Quick_Nick]

Nope. Infinite density just means "nonzero mass in zero volume".

If you have a mass of 1 Earth mass all concentrated at one point, you have infinite density at that point, but it's still 1 Earth mass, and the gravitational acceleration at any given radius is the same as the surface gravity for a 1 Earth mass sphere of that radius.

I realized that, probably thanks to sleep.
It still doesn't make quantum sense to me though.

 

[Capt_hensley]

if a black hole has huge gravity so that nothing traveling at the speed of light can escape it
and the fastest speed is the speed of light
how can Hawking radiation escape the gravity of a black hole?

 

[palebluevoice]

if a black hole has huge gravity so that nothing traveling at the speed of light can escape it
and the fastest speed is the speed of light
how can Hawking radiation escape the gravity of a black hole?

Light cannot escape from beyond the event horizon of a black hole(within the event horizon radius assuming it's round). Hawking radiation is emitted close to, but not inside of the event horizon radius.

The event horizon is just the radius by which the escape velocity begins to exceed the speed of light.