Update: The original post below was written as part of Cosmic Variance. Every time you move your blog, stuff like this changes. Here, the way to put something into Latex is to start your comment with the tag
{latexpage}
Except — important! — use square brackets [] rather than curly braces {}. Then anything you put inside dollar signs gets interpreted as a LaTeX math formula, as usual. So
$g_{\mu\nu}$
should show up as
.
I’m using the QuickLaTeX plugin; more details here.
This stands in marked contrast with the previous system, explained below.
——————————————————-
For a long time I was reluctant to joint the many other sciencey blogs that had integrated equations by providing support for LaTeX, the technical typesetting system that nearly every physicist and mathematician uses. Possible reasons for this attitude include:
- We felt it was important to remain accessible to a wide range of readership, and feared that the appearance of equations would put people off (and tempt us into being unnecessarily technical).
- It sounded like work.
You can decide for yourself which is more true. The good thing is, there is no wrong answer!
But right now I am uninspired to blog because my brain is preoccupied with real science stuff. So I thought of posting about some of the fun ideas in quantum mechanics I’ve been learning about. But there’s really no way to do it without equations. So for that reason, and in belated honor of Donald Knuth’s birthday, I went and installed the LatexRenderer plugin.
So now it’s easy to include equations; they should even be available in comments. All you have to do is type [ latex ], then your LaTeX commands, then [ /latex ], except no spaces. So for example
[ latex ]R_{\mu\nu}-\frac{1}{2}Rg_{\mu\nu}=8\pi G T_{\mu\nu}[ /latex ],
if you left out the spaces, should produce
.
There are a million online tutorials; try this list of commands to get you started. Use comments to this post to try it out. (Sadly, no preview, so be careful, and this post will remain open for playing around.) One thing I’ve noticed: don’t use linebreaks within the formulas, just put everything on the same line. And use “displaystyle” if you want the look of a set-off (rather than in-line) equation.
$latex P_{avg}=dfrac{Delta m}{Delta t} c^2=dfrac{Delta p}{Delta x} c^2$
cool
$latex partial_apartial^aphi~=~-m^2phi~+~g^2phi^3 F_{ab}F^{ab}$
with the action
$latex
S~simeq~ int d^4x Big(frac{1}{2}|nablaphi|^2~+~phi^2big(sqrt{-g}kappa R~+~frac{1}{2}m^2~-~frac{g^2}{4}phi^2 F_{ab}F^{ab}big)Big),$
I’m seeing all sorts of familiar and unfamiliar maths here! Hey, is that a Lie bracket?
Dang it, now I feel really guilty I didn’t finish my next SUSY QM post today. I find it’s actually harder to write the prose in between the equations than the equations themselves. . . .
$latex {Q, Q^dag} = mathcal{H},$
$latex {Q, Q} = {Q^dag, Q^dag} = Z.$
Sean, I vote for Christian (#57) winning the thread. For the obvious reason.
$latex ihbarfrac{partial}{partial t}left|Psi(t)right>=Hleft|Psi(t)right>$
OK, but you do need a previewer.
LatexRender is cool in its quirky way, slightly naive, limited and won’t be the future, but hey, it’s fun.
You wouldn’t get the superstring guys using it though. 😉
For the pedantic, let’s make that Hamiltonian explicitly time dependent
$latex ihbarfrac{partial}{partial t}left|Psi(t)right>=H(t)left|Psi(t)right>$
$latex sum_{n=1}^{infty}n = -frac{1}{12}$, therefore physics is crazy!
I discovered latex on wordpress recently, so I’ve been going latex crazy on my website.
Electrical theory
So, as you say in your book, covariant derivative of $latex V ^mu $ is:
$latex nabla _{nu}V^mu = partial _nu V^mu+Gamma^mu^{sigmanu}V^sigma$
I think, but I suppose I don’t remenber index placement really.
(anyway, I was just trying latex 🙂 )
Mmm, $latex sigmamu$ should be down… :S
$latex (x+y)^n=displaystyle sum_{k=0}^n left ( n atop k right ) x^{n-k}y^k$
Now, the real question is, can we use LaTeX to write a Hamiltonian for the Quantum of Solace?
Quadratic thingy, try 1
$latex x=dfrac{-bpmsqrt{b^2-4ac}}{2a}$
Cool!
$latex -frac{hbar^2}{2m}nabla^2Psi + VPsi = ihbarfrac{partial}{partial t}Psi$
Whoo hoo! Worked first time!
Previews are for wussies!
You guys better worry whether Steven Hawking was right in his introduction to _A Brief History of Time_. He repeated advice given to him that for every equation used in the text, he would decrease his readership by 50%. By my estimates, the readership of this blog will soon be approximating the Planck Length.
$latex displaystyle x^3 + p x + q = 0 Longrightarrow $
$latex displaystyle sqrt[3]{sqrt{left(frac{p}{3}right)^3+left(frac{q}{2}right)^2} – frac{q}{2}} – sqrt[3]{sqrt{left(frac{p}{3}right)^3+left(frac{q}{2}right)^2} + frac{q}{2}}$
I meant to say:
$latex displaystyle x^3 + p x + q = 0 Longrightarrow$
$latex displaystyle x = sqrt[3]{sqrt{left(frac{p}{3}right)^3+left(frac{q}{2}right)^2} – frac{q}{2}} – sqrt[3]{sqrt{left(frac{p}{3}right)^3+left(frac{q}{2}right)^2} + frac{q}{2}}$
$latex displaystyle oint_s vec{B} cdot da$
here goes…
$latex begin{tabular}{ll}1 &21&2end{tabular}$
$latex begin{tabular}{ll} 1 2 1 2end{tabular}
$latex begin{tabular}{ll} 1 2 1 2end{tabular}[tex]