« | Home | Categories | »


Posted on March 14th, 2011 at 17:53 by John Sinteur in category: Software

If you want to do math in your web pages, check out MathJax

Here are some samples:

The Lorenz Equations

\dot{x} & = \sigma(y-x) \\
\dot{y} & = \rho x – y – xz \\
\dot{z} & = -\beta z + xy
\end{aligned} \]

The Cauchy-Schwarz Inequality

\[ \left( \sum_{k=1}^n a_k b_k \right)^2 \leq \left( \sum_{k=1}^n a_k^2 \right) \left( \sum_{k=1}^n b_k^2 \right) \]

A Cross Product Formula

\[\mathbf{V}_1 \times \mathbf{V}_2 = \begin{vmatrix}
\mathbf{i} & \mathbf{j} & \mathbf{k} \\
\frac{\partial X}{\partial u} & \frac{\partial Y}{\partial u} & 0 \\
\frac{\partial X}{\partial v} & \frac{\partial Y}{\partial v} & 0
\end{vmatrix} \]

The probability of getting \(k\) heads when flipping \(n\) coins is

\[P(E) = {n \choose k} p^k (1-p)^{ n-k} \]

An Identity of Ramanujan

\[ \frac{1}{\Bigl(\sqrt{\phi \sqrt{5}}-\phi\Bigr) e^{\frac25 \pi}} =
1+\frac{e^{-2\pi}} {1+\frac{e^{-4\pi}} {1+\frac{e^{-6\pi}}
{1+\frac{e^{-8\pi}} {1+\ldots} } } } \]

A Rogers-Ramanujan Identity

\[ 1 + \frac{q^2}{(1-q)}+\frac{q^6}{(1-q)(1-q^2)}+\cdots =
\quad\quad \text{for $|q|<1$}. \]

Maxwell’s Equations

\[ \begin{aligned}
\nabla \times \vec{\mathbf{B}} -\, \frac1c\, \frac{\partial\vec{\mathbf{E}}}{\partial t} & = \frac{4\pi}{c}\vec{\mathbf{j}} \\ \nabla \cdot \vec{\mathbf{E}} & = 4 \pi \rho \\
\nabla \times \vec{\mathbf{E}}\, +\, \frac1c\, \frac{\partial\vec{\mathbf{B}}}{\partial t} & = \vec{\mathbf{0}} \\
\nabla \cdot \vec{\mathbf{B}} & = 0 \end{aligned}

Write a comment


  1. It doesn’t work as well with NoScript running. 🙂

  2. True; but NoScript does permit you to temporarily allow mathjax.org. This is great, because you get to see the original code and then the resulting visuals. Neat! I will probably never have any use for it, but certainly appreciate the effort that went into developing it.

Miyako, Japan

Posted on March 14th, 2011 at 12:48 by John Sinteur in category: Great Picture

Write a comment


  1. For once, words fail me.

  2. Only one thing comes to my mind – “Oh Sh!t”…

  3. This town would be my choice as a place to live in Japan; I walked through Japan 1987, and the old streets and the knifemakers shop in Miyako enchanted me straight away. I believe in the Nihonjin’s ability to weather such storms. Power to them. JR

  4. I can’t even make a funny about it. Incomprehensible!

Fukushima Nuclear Accident – a simple and accurate explanation

Posted on March 14th, 2011 at 12:45 by John Sinteur in category: News

Read this before watching the news again.

Write a comment


  1. While accurate and simple on the technical point of view, looks like the guy is seriously trying to downplay the problem even if it has been dubbed “alarming” by official sources and technicians from many nations.

    I have a basic knowledge of nuclear plants (coming from university studies and personal interest), and I’m not completely sold on his “it’s all right, really, everything is going smoothly” stance. News coverage may mess up a bit, but what is reported is preoccupying at best.

    This article is featured prominently on blogs who sport a “say YES to nuclear” badge, and this is fishy.

  2. Thanks John.

    “Trouble at’ mill!”
    “Oh no! What kind of trouble?”
    “I dunno…”

    For survivors in the area of devastation, evacuation will be necessary anyway because of the complete destruction of infrastructure. No clean water, no heat, power or sanitation.

    Steel mills, oil refineries, etc. inundated. We can not imagine the difficulties. Fishy or not, this is the situation that those people have to deal with.

    Some Canadian engineers just came back from that power station and one says he is not going back. Something about the earth shaking on too regular a basis, not about nuclear contamination.

  3. It is featured on a lot of pro nuclear blogs because those are read by people who actually know about nuclear power. Mainstream media gets a lot of attention by being alarmist and playing the publics baseless fear that this will be another Chernobyl. No many people reading cnn.com are interested in well reasoned technical explanations to somewhat complicated issues. They want articles that start off “Fears Loom over Japan about state of critical reactor that could be the worst nuclear disaster since Chernobyl”.

  4. This will cheer you up. It is now being widely reported that the company that operates these plants has a history of cover-ups including falsifying nuclear safety records, non-maintenance of vital infrastructure and so on. If they have lied so many times in the past ……..

  5. What BS. Moderator rods in place and the uranium rods are still melting. What is going to contain the radioactivity if it gets into the third line of defense? Nothing.

    Have you visited the site? Let me know how it looks when you go in to help them. Take your lead underwear.

  6. If the journalists are doing such a poor job of reporting the facts, why don’t you go there. Take your lead underwear.

    I doubt there is a nuclear scientist within a 100 miles of the site.

  7. It might be worth posting an update. It looks like this post was not written by someone qualified to judge the circumstances.


Crowley resigns as State Department spokesman

Posted on March 14th, 2011 at 10:30 by John Sinteur in category: News


P.J. Crowley abruptly resigned Sunday as State Department spokesman over controversial comments he made about the Bradley Manning case.

Sources close to the matter said the resignation, first reported by CNN, came under pressure from the White House, where officials were furious about his suggestion that the Obama administration is mistreating Manning, the Army private who is being held in solitary confinement in Quantico, Virginia, under suspicion that he leaked highly classified State Department cables to the website WikiLeaks.

Speaking to a small group at MIT last week, Crowley was asked about allegations that Manning is being tortured and kicked up a firestorm by answering that what is being done to Manning by Defense Department officials "is ridiculous and counterproductive and stupid."

So he touched a nerve, didn’t he?

Write a comment


Posted on March 14th, 2011 at 10:13 by John Sinteur in category: Cartoon

Write a comment

Japan: earthquake aftermath – The Big Picture

Posted on March 14th, 2011 at 8:43 by John Sinteur in category: Great Picture


Japan raced to avert a nuclear meltdown today by flooding a nuclear reactor with seawater after Friday’s massive earthquake left more than 600 people dead and thousands more missing. Towns in the country’s northeast coast were literally wiped away by an ensuing tsunami, leaving countless people seeking shelter in the aftermath of the quake, which measured 8.9 on the Richter scale and was the country’s strongest recorded quake. — Lloyd Young 44 photos total)

Officials in protective gear check for signs of radiation on children who are from the evacuation area near the Fukushima Daini nuclear plant in Koriyama. (Kim Kyung-Hoon/Reuters) #

Write a comment

4chan hackers leak internal Bank of America emails

Posted on March 14th, 2011 at 8:26 by John Sinteur in category: Robber Barons


Anonymous, a group of online hackers that frequently take up politically charged causes such as bringing down the websites for Visa and other credit card companies, has released a massive batch of internal Bank of America emails.

Mirror pt 1: http://imgur.com/1ahFt

Part 2: http://imgur.com/5v5bh

Final bit: http://imgur.com/rNZPC

Write a comment


  1. I took a quick look but couldn’t find any deeper info yet. I’ll be curious to find out how they got the info, whether it’s the same as what WL has or whether they hacked email and got their own separate material, and more importantly, how much damaging info there is in this.