@Obliv Dark matter was created to explain how the SMBH can hold together the rest of the galaxy

Not the other way around

There already is some evidence that there are black holes in the centers of galaxies

so what if you forgo the SMBH theory as a whole? Is there such a description? tangent: How do we observe the movement of galaxies (not necessarily away from us as given by redshift)? What causes this movement? Not sure if that is phrased correctly I can clarify if you need me to.

@Obliv I really can't work on this atm, I've got hw

@sirC okay np. Thanks for your time.

I am to find the volume of a tetrahedron "bounded by the planes $x+2y+z = 2$,$x = 2y$, $x = 0$, and $z = 0$" though, the only planes I see are $x + 2y + z - 2 = 0$ and $x - 2y = 0$. Not sure how $x = 0$ and $z = 0$ define planes

well, $\lbrace (x,y,z) \vert x=0\rbrace$

likewise for z=0, these are planes:)

the same way that in 2d $x=1$ defines a vertical line

@andras thanks :) I lazily assumed you needed more information to specify a plane but that is enough information (it lies on the plane if it is normal to a scalar multiple of <1,0,0>)

or if you think of it like this: $\vec n\cdot\left(\vec r-\vec r_0\right)=0$ is the equation of the plane

yup

a single linear constraint between your 3 coordinates will give you a 2-dimensional linear space

that's fancy for what I said 2 lines above

@AndrasDeak Why did you write out "\lbrace" and "\rbrace"?

${(x,y,z) \vert x=0}$

without \*brace ^

you can do \{ and \}

$\{$

You can also escape the braces directly as \{

oh, but that's silly:P

I'm already being lenient by omitting \left/\right....

but thanks for the tip

@andras I would say your method is silly but I write \mathbb{} instead of \Bb{} and I still don't know why

mathbb is the standard amsmath, I would think

I'm pretty sure that's what the bible short math guide uses

well then that's my reason now.

It's dangerous to go alone. Take this!

only mathbb, mathit etc inside, except the \Bbbk single symbol

same for lbrace

link doesn't work @andras

@Obliv D: it does for me

which browser do you use?

firefox, but an ftp link shouldn't be browser-specific

the link is also found here if you search for "short math guide"

still doesn't work. I think it might be because of the network I'm on with these library computers at my school. I'll try again at home

I'm pretty sure the issue is not on my side:)

probably ftp is blocked?

that's how you get drugs, you know

works for me, too, although the ftp link oddly takes a bit longer to load than an "ordinary" pdf

Must retreat to my home now. See ya

@AndrasDeak whaaaaat? And here I've always wasted my time in back alleys for that :P

have a safe trip

Why did women evolve to always be cold?

umm...

I'll be over there $\leftarrow$

@GPhys are you getting into gauge theory in QFT or something?

I thought you were taking QM

@GPhys Ahhhh, a ghost. I banish thee by the power of BRST!

noooooo

(I was shortly tempted to actually kick you from the room for the joke :P)

@ACuriousMind What cool acronym do you want to be a part of, J?

JNDICE?

@0celo7 Clearly I will develop the first rigorous BJ theory

You're a child

@0celo7 I have no idea what you mean :)

Those are my initials :P