Large Hardon Collider

[Ferion]

Those are some pretty awesome images. I actually have a question. From what I read, we aren't really too sure what happens when black holes collide, but some research suggests that they actually shoot off in opposite directions once they get too close. I don't know how credible that theory is though, I forget exactly where I read it. So my question is, if we suspect that there are super massive black holes at the center of most (or all) galaxies, why is it that when we see two spiral galaxies collide they'll form an elliptical galaxy rather then repel each other after a while?

[Woozie]

Someone can correct me if I'm wrong, but it's currently predicted that the two super massive black holes in the centers of colliding galaxies will merge into one, as far as I know.

[Ferion]

I found the article where I read that they repel each other:

http://www.universetoday.com/13002/w...holes-collide/

Edit: The article is from 3 years ago so the theory could have completely reversed since then, I didn't do much reading beyond this article.

[Khamsin]

Those are some pretty awesome images. I actually have a question. From what I read, we aren't really too sure what happens when black holes collide, but some research suggests that they actually shoot off in opposite directions once they get too close. I don't know how credible that theory is though, I forget exactly where I read it. So my question is, if we suspect that there are super massive black holes at the center of most (or all) galaxies, why is it that when we see two spiral galaxies collide they'll form an elliptical galaxy rather then repel each other after a while?

I always figured nothing could escape a black hole, not even another black hole.

[Woozie]

That's only true once you cross the event horizon. Gravity could fling them apart well before they ever get that close to each other.

@Ferion: Maybe I'm the one who's wrong here. Or maybe they just aren't sure yet.

[Ferion]

Yeah I was just kind of curious because I was watching a lecture by Neil DeGrasse Tyson and some one asked him what happens when two black holes collide, and he basically said he's not really sure. So I started looking it up and I found that first article I posted. But now that I'm looking at some more recent explanations they basically say that they both leak energy out of the system until one is able to consume the other, so forget about what I asked haha.

[Kaylia]

Those are some pretty awesome images. I actually have a question. From what I read, we aren't really too sure what happens when black holes collide, but some research suggests that they actually shoot off in opposite directions once they get too close. I don't know how credible that theory is though, I forget exactly where I read it. So my question is, if we suspect that there are super massive black holes at the center of most (or all) galaxies, why is it that when we see two spiral galaxies collide they'll form an elliptical galaxy rather then repel each other after a while?

Like Woozie said, they are going to merge if they get close to each other. It's true we don't know what will happen in detail from a QM/GR perspective, but the collision between 2 large masses that obey the laws of gravity should produce something heavier. However, because the event horizon is going to be deformed considerably when both blackhole are close, it become a very complex "event horizon".

Now, if both object are outside the event horizon, they won't "collide", they are just going to follow a normal trajectory. In certain (most) cases , a blackhole could be ejected in a different direction.

I'm not sure there is a simple explanation for elliptical galaxy. All I can say is that both classical and relativistic simulation will produce the same result..so it's basically statistics, dynamics and gravity applied to galaxy.
[edit]
Changed lot of thing to be less wrong!

[Eliseos]

You guys are probably sick of these by now, but I keep finding awesome ones:



Mind blown.

[Woozie]

I could never get sick of those.

[Eliseos]

I always figured James Stewart was pretentious and the violin airhole thing was for the S in his name

Also Woozie I think it was you who said E&M II was the hardest undergrad physics class? 100% agree with it (and if you didn't say that, then I'm making that claim). Have an exam tomorrow on Maxwell's equations everything including and after Maxwell's correction to Faraday's law, conservation laws, and electromagnetic waves. It seems like nothing that I've been studying this week has had any retention. Way too many formulae and letters to remember.

[Woozie]

E&M I was the hardest. We don't have a part II (well we do, but it hasn't been offered for the entire time I've been here, which is like 6 years).

[Kaylia]

You guys are probably sick of these by now, but I keep finding awesome ones:

Mind blown.

They are hilarious. I don't think any meme managed to makes me laugh as much as this one did..there is so many gem.


EM was (with QM) the hardest class imo. EM was actually worse since you had nasty differential equation to solves, and I was never good at that.

[Eliseos]

E&M I was the hardest. We don't have a part II (well we do, but it hasn't been offered for the entire time I've been here, which is like 6 years).

They are hilarious. I don't think any meme managed to makes me laugh as much as this one did..there is so many gem.


EM was (with QM) the hardest class imo. EM was actually worse since you had nasty differential equation to solves, and I was never good at that.

What did your EM classes cover? For us, part 1 was a month long review of vector calc, then to E-fields/Gauss's Law, then electric dipoles/polarization, and we ended around magnetic fields/ampere's law. Part 2 has been more magnetic stuff, magnetization, then what we're into now, Maxwell's equations, conservation laws, and EM waves.The last three has been the toughest so far, with Polarization/Magnetization up there as well.

[Woozie]

We covered pretty much everything you just mentioned in your post, and pretty much in that same order. The very last thing we did was EM waves.

[Mizango]

I could never get sick of those.

^ NEVER

[Woozie]

Words of wisdom from my math book:

"I have yet to see any problem, however complicated, which, when you looked at it in the right way, did not become still more complicated"
-Paul Anderson

[Eliseos]

Ugh, I could not imagine doing all of that in only one semester. Its hard enough in two lol.

Exam today went ok. First question asked a bunch of easy questions, like differential form of Poynting's vector, Maxwell's equations in a vacuum, etc. Next was calculate force and pressure on a solenoid using Maxwell's stress tensor (homework problem and he did it in class so I think I got most of the points). Last problem is where it got hard. First we had to write Maxwell's equations in linear, conducting material, then find wave equation for E. We were then given a solution for E, told to find what restriction the wave equation places on k^2, and then asked to find skin depth and phase difference between E and B. I had no idea at all on these last few glad it's over though, until finals.

[Woozie]

http://www.smbc-comics.com/comics/20110408.gif

[Eliseos]

Haha, awesome. Needs another panel somehow adding in that future mathemetician saying "because fuck you that's why!"

[Mizango]

Haha, awesome. Needs another panel somehow adding in that future mathemetician saying "because fuck you that's why!"

lmao, too true.