At the center of a black hole is it the same time as the moment of its formation?

[Kuciwalker]

Originally posted by Ben Kenobi
Yes, time dilation would be there, but it doesn't reach infinity until there is a singularity. I'm beginning to think you don't understand a thing about stellar collapse and formation.

I'm beginning to think you don't understand the concept of a limit

[KrazyHorse]

Seriously, Ben: I know they showed you a bunch of pretty pictures in whatever ****-level class you took on stellar structures, but there are some fundamental issues here with general relativity they obviously never bothered to describe to you.

[Heraclitus]

Originally posted by Kuciwalker


I'm beginning to think you don't understand the concept of a limit

That is just mean.

[KrazyHorse]

But true.

[Ben Kenobi]

For a non-rotating body the rate of mass accretion (measured by an outside observer) for any sphere of radius R drops to zero as the mass in the sphere approaches an amount sufficient to create an event horizon.

Umm, no. Not in a type Ia supernova.

What happens is that you have a small star, say a white dwarf that is supported by electron degeneracy pressure. The mass doesn't stream on in single particles, it streams in amounts that are much greater then this. As the star accretes more and more matter, it reaches a certain limit which I already described to you (funny you don't mention it) which is about 1.4 solar masses on a white dwarf.

As the star approaches this point, say at 1 solar mass, it would have a radius of, say 8 one thousandths of a solar radii. At 1.2 solar masses, the radii drops to about 5 one thousandths of a solar radii.

From there on, it's just a matter of time. You can have a white dwarf which temporarily has more mass then 1.4 solar masses, but that only happens in special circumstances. It's not stable, and what is happening is that the accretion drops mass at rates high enough for the star to jump over the limit.

[Ben Kenobi]

Uhh, I'm pretty sure Ben didn't even finish his BSc. At least not in physics. (Didn't you end up getting a degree in history?)

Yes I did.

I was a major in physics and astronomy and yes, I did do a few classes on general and special relativity.

We are the ones who have to worry about stuff like stellar structures, etc. that I'm sure KH found so engrossing in his lectures.

[KrazyHorse]

*teabag

[KrazyHorse]

Originally posted by Ben Kenobi


Umm, no. Not in a type Ia supernova.

What happens is that you have a small star, say a white dwarf that is supported by electron degeneracy pressure. The mass doesn't stream on in single particles, it streams in amounts that are much greater then this. As the star accretes more and more matter, it reaches a certain limit which I already described to you (funny you don't mention it) which is about 1.4 solar masses on a white dwarf.

As the star approaches this point, say at 1 solar mass, it would have a radius of, say 8 one thousandths of a solar radii. At 1.2 solar masses, the radii drops to about 5 one thousandths of a solar radii.

From there on, it's just a matter of time. You can have a white dwarf which temporarily has more mass then 1.4 solar masses, but that only happens in special circumstances. It's not stable, and what is happening is that the accretion drops mass at rates high enough for the star to jump over the limit.

Do you seriously not understand that what I'm telling you has absolutely nothing to do with degeneracy pressures or the physical process by which you're accreting matter?

[Ben Kenobi]

Seriously, Ben: I know they showed you a bunch of pretty pictures in whatever ****-level class you took on stellar structures, but there are some fundamental issues here with general relativity they obviously never bothered to describe to you.

Which is why we've engaged in a thrilling discussion on the pauli exclusion principle?

All I see is someone with a degree basically wanking off and not actually discussing the issue at hand because apparently we are all peasants who won't understand the calculations.

[Ben Kenobi]

Do you seriously not understand that what I'm telling you has absolutely nothing to do with degeneracy pressures or the physical process by which you're accreting matter?

Yes, and I'm saying that in the real world, these things matter. You have an idealised situation, which makes sense in theory, and it is correct. I never said it wasn't. Just things aren't so neat and tidy. Mass can and does tend to push the stars over the limit and we can detect it and see it happening as outside observers because it happens in large enough chunks.

[KrazyHorse]

Ben, here's what your post looks like to me:

In a Type Ia supernova the laws of general relativity are suspended because my teacher told me something about fermion degeneracy and stuff. The reason I'm talking about Type Ia's is that you said something about mass accretion, and I recognize the word "accretion", despite the fact that the two uses are only tangentially related to each other. Now I'm going to type down a bunch of numbers I had to memorize to do well on the midterm which I think make it look like I know what I'm talking about.

[KrazyHorse]

Originally posted by Ben Kenobi


Which is why we've engaged in a thrilling discussion on the pauli exclusion principle?

NO! We're not talking about the Pauli exclusion principle you ****ing loon. We're talking about what happens long after that breaks down. We're talking about what would happen even if there was no such thing as fermions, even if radiation pressure didn't exist, even if we had a monkey firing cannonballs of pure neutronium into our mass accumulation.

Jesus ****ing Christ.

[KrazyHorse]

Originally posted by Ben Kenobi
I was a major in physics and astronomy and yes, I did do a few classes on general and special relativity.

Oh, really.

Reeeeeeaaaalllly.

What text did you use to learn GR, Ben?

[Heraclitus]

Originally posted by KrazyHorse
Are you going to continue past a baccalaureate?

Fully intend to.

Originally posted by KrazyHorse
How much longer do you have before you need to make that decision?

Some time, unless I don't keep my average high enough, in that case quite some time, but this scenario is unlikely.

Originally posted by KrazyHorse
If you are going on, what are you thinking about in terms of grad school (both area of research and school)?

I currently quite strongly favor the " Fizika osnovnih delcev in jedra", which might be best translated as basic particle physics on the same I university that I am currently attending since I love how (University of Ljubljana, faculty of Mathematics and Physics) closely it works with this institute .

Originally posted by KrazyHorse


I like messing with you. You remind me of me.

Should I be or about that?

Originally posted by KrazyHorse
(just so you get that I'm not actually fighting with you, here are 6 more winking smilies)

Damm, why did you do that I was having so much fun, now I have to be polite.

Wait, I jsut got it! I don't have to! You were patronizing me!

Originally posted by Heraclitus
Have I mentioned I hate you so much I would need to write up a whole new mathematical language just to loosley describe my emotions?

[Ben Kenobi]

*sigh

I gotta get going. I am tutoring a student today.

You have succeeded in pissing me off enough to make me late!