Popping the Kids' Balloons

Minister for Home Affairs: I’d like to answer this question if I may in two ways. Firstly in my normal voice and then in a kind of silly high-pitched whine

Cocktail Party Physics: helium: a weighty question

One-fifth of the world’s helium supply is used in MRIs. The typical MRI requires superconducting magnets and, since we haven’t figured out room-temperature superconductivity yet, they require liquid nitrogen or liquid helium to keep them in the superconducting state. Most systems use a closed cycle – helium cools the magnet, warms up in the process, turns to a gas, and is re-liquefied. A typical MRI magnet, however, requires 1700-2000 liters of liquid helium. Older models have to be refilled on a timescale from months to years, while newer models advertise that they “never” need to be refilled. (I’m about to buy a system like that. We’ll see how long ‘never’ is.) MRI resolution gets better the larger the magnetic field. Larger magnetic fields require larger magnets and thus more liquid helium.

What's Cooking in the Pizza Lab?

The Pizza Lab: Bringing Neapolitan Pizza Home (aka ‘The Skillet-Broiler Method’)

Real food science — bringing the physics along with the recipe.

It’s basic thermodynamics. Air at a given temperature has less energy than stone at a given temperature. Because of this, even if both my stone and the air in my oven are at 550 degrees, the part of the pizza in contact with the stone cooks much more rapidly than the top. By the time the bottom is crisp, the top has yet to take on any significant color.
The solution to this is quite simple, and happily makes for a much cooler kitchen as well: forget preheating the oven: just use the broiler. A broiler not only cooks via hot air like the oven, but more importantly, it adds a significant amount of radiant heat to the mix, cooking the top of the pizza directly with electro-magnetic waves—a much more efficient means of heat transfer.

Full of Win

In case you haven’t heard already, Jon Stewart and Steven Colbert have announced a march in Washington, DC on October 30th. It’s not the “restore truthiness” theme (officially) I had mentioned a few days ago, being pushed by reddit. Instead it’s the Rally to Restore Sanity/March to Keep Fear Alive. I plan on going, and if any readers show up, you can’t miss me — I’ll be the guy wearing a shirt.

But the good news doesn’t stop there. The DonorsChoose donations have just surpassed $250,000, with a new goal of half a million by October 1st.

And They Invented Math!

Beware of Greeks Bearing Bonds

The Greek debt crisis.

When Papaconstantinou arrived here, last October, the Greek government had estimated its 2009 budget deficit at 3.7 percent. Two weeks later that number was revised upward to 12.5 percent and actually turned out to be nearly 14 percent. He was the man whose job it had been to figure out and explain to the world why. “The second day on the job I had to call a meeting to look at the budget,” he says. “I gathered everyone from the general accounting office, and we started this, like, discovery process.” Each day they discovered some incredible omission. A pension debt of a billion dollars every year somehow remained off the government’s books, where everyone pretended it did not exist, even though the government paid it; the hole in the pension plan for the self-employed was not the 300 million they had assumed but 1.1 billion euros; and so on. “At the end of each day I would say, ‘O.K., guys, is this all?’ And they would say ‘Yeah.’ The next morning there would be this little hand rising in the back of the room: ‘Actually, Minister, there’s this other 100-to-200-million-euro gap.’ ”

This went on for a week. Among other things turned up were a great number of off-the-books phony job-creation programs. “The Ministry of Agriculture had created an off-the-books unit employing 270 people to digitize the photographs of Greek public lands,” the finance minister tells me. “The trouble was that none of the 270 people had any experience with digital photography. The actual professions of these people were, like, hairdressers.”

Chirp

Finally signed up for “The Twitter.” When I first learned of it, I thought it would just be a compendium of noise, since the threshold to tweet is so low. And this is precisely why I don’t do Facebook very much — I am just not all that interested in the level of minutia of my friend’s lives, and I shudder to think they are that interested in mine (or feel that they’re missing out because I don’t post such trivialities very often). But today I found out that Steve Martin is tweeting, so I signed up to follow that.

I don’t want it to be a collection of “Boy, I could use more fiber in my diet” or “De-linting my belly button!” tweets. On the other hand, I do have these random thoughts, which I occasionally blog. That’s the kind of stupid stuff I’ll probably tweet. Probably.

Twitter: Swansontea

I understand it’s protocol to follow those who follow you, but … no. I’m not going to return the favor in order to be a statistic, or even to be polite. I am a physicist, and have no social skills. Follow only if you have some slight possible interest in the content.

Legislating Reality

Senate set to slam science

There are certainly ample political reasons to sometimes ignore science. Fine. Say that. But discounting or demonizing science for political ends needs to stop. Science is not subject to legislation. It’s one thing to make the case that we cannot afford to deal with greenhouse gasses right now. It’s another entirely to claim greenhouse gasses are not putting us at risk.

The Needs of the Many Outweighs The Needs of the Few

Self-organizing traffic lights

The key is that this kind of control does not fight the natural fluctuations in the traffic flow by trying to impose a certain flow rhythm. Rather, it uses randomly appearing gaps in the flow to serve other traffic streams. According to their simulations, this strategy can reduce average delay times by 10%–30%. Remarkably, the variation in travel times goes down as well, although the signal operation tends to be non-periodic and, therefore, less predictable. You can’t say precisely how the lights will go on and off, but you can be sure your drive will be shorter.

So it sounds like if you’re in a dense group of cars, you’ll see more green lights, but if you are alone or in a sparsely bunched group, you’re likely to get a red, Which bunches you up, et cetera, et cetera. IOW, opposite of the way lights seem to run.

A View of the Neighborhood

The Big Picture: Around the Solar System

With dozens of spacecraft currently orbiting, roving or otherwise and traveling through our solar system, I thought it would be interesting to get a general snapshot in time, using images from NASA and ESA spacecraft near Mercury, Earth, the Moon, Mars, Saturn and a few in-transit to further destinations. Collected here are recent images gathered from around our solar system, at scales ranging from mere centimeters to millions of kilometers.