J&C’s Happy Valley Ho-Hum

So I’ve set this blog up to automatically repost things that I share from google reader. Cool idea in theory, but I’m constantly hitting the share button on my phone in Reeder (great app, by the way, check it out.) accidentally. So I decided to only create drafts rather than auto publish everything. That way I have to specifically approve them. That means a lot less posts around here unless Cami starts posting more.

Oh well.

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I've said it before, and I'll say it again. Resurrection = Zombie apocalypse. It WILL happen, people.

· Sesame Street: smell like a monster [YouTube]

Moar gifs dis-a-way!

At a faculty lunch yesterday, I heard about an ingenious scheme used by some universities in New York, where much rental housing is rent controlled.  Here are the three key elements, as it was described to me by one of my colleagues:

1. The university buys a rent-controlled building.  The purchase price is low, because the existing landlord cannot make much money renting it.

2. The university then rents the apartments to its own senior faculty, who view this as a great perk.  In essence, the difference between the free-market rent and the controlled rent is a form of compensation for the professor.  As a result, the university can reduce the professor's cash compensation by an equivalent amount.  The university is effectively earning the market rent for the apartment.

3. But it gets even better.  The implicit rental subsidy is a form of non-taxed compensation.  Normally, if an employer gives an employee a perk like this, the subsidy is taxable income (unless the perk is deemed a working condition required to do the job, like a hotel manager living in a hotel).  But here, the university can claim there is no subsidy: It is only charging what the rent-control law requires.  Because of this tax treatment, the implicit subsidy is worth even more to the professor than the equivalent cash compensation.  This fact allows the university to reduce the professor's cash compensation by an even greater amount.  Thus, the university effectively earns even more than the free-market rent on a real estate investment purchased much lower than the free-market price would have been.

In the end, the goal of the rent control laws is thwarted (the low rents are enjoyed by well-paid tenured faculty rather than the needy), the income tax laws are thwarted (a sizable part of compensation is untaxed), and all this is done by a nonprofit institution (the university) whose ostensible purpose is to serve the public interest.

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I did. I really did.

LOOK DOWN, NOW UP, I HAVE AN AWARD You just read this in my voice. Submitted by: evilclownmonkey...

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Awesome.

This image is stunning. And not just because, well, it’s all explodey and stuff:

[Click to explodenate.]

The three panels show a 1986 test of a Tomahawk cruise missile. The missile traveled 640 km (400 mile) low over the terrain to detonate above the target, a decommissioned fighter plane. It’s pretty clear the test was a success.

But what caught my eye immediately was the middle panel. Let me zoom it for you:

[Click to hugely embiggen!]

Now look carefully there. When the missile exploded, the expanding debris cloud from the vaporized weapon was probably moving faster than the speed of sound. Even so, in this second picture you can see none of it had touched the plane yet when the shot was snapped.

Yet look at the plane: it’s on fire. How can that be?

It’s because of something that moves much faster even than supersonic debris: light. When the warhead exploded, it sent out a huge pulse of heat in the form of infrared photons, light that travels about a million times faster than sound. As far as that flash of heat was concerned, the expanding debris was standing perfectly still! There was plenty of time for that heat to get to the plane and set it aflame before the explosion itself could reach that far.

Note that third picture, taken from an oblique angle. You can match the features in the fireball to the ones in the second picture. The ground around the plane is lit up by the blast, and again no debris had yet reached the plane itself.

It’s a little counterintuitive that the explosion works this way. We think of explosions as being made of expanding stuff, but it turns out that light has its role to fill as well. In fact, this is important in other ways: one idea to push Earth-crossing asteroids out of the way is to light off a nuke nearby. The force of the explosion itself isn’t all that great in space, because there’s no air to create a shock wave. The only momentum you give the rock directly is the expanding debris from the bomb itself, which isn’t all that much. But the blast of heat/light is immense, and can heat the asteroid past its vaporization point. The flash-vaporized rock expands, pushing on the asteroid like a rocket motor.

Unfortunately, modeling of this shows it doesn’t work terribly well compared to other methods (like simply slamming the asteroid with a space probe like a linebacker hitting a quarterback). Still, you need to consider all the details when thinking about things like this. The devil hides in them, y’know!

Oh, and one more thing. This Tomahawk test was done 24 years ago. How much has the technology improved since then?

Yikes.

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Caution: language. But funny.

[Steve Jobs mentions the iPad will support the new HDR photos feature] Me: Why did he just say HDR photos on iPad? Me: There is no camera. Shawn Morrison: Unless they’re bumping the iPad today too. Obviously the next iPad will have a camera. Me: At l...

Miss the original? If Historical Events Had Facebook Statuses

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