Going and Going and Going …

I bought some batteries, but they weren’t included. So I had to buy them again.

Steven Wright

Cocktail Party Physics: batteries not included

Some historians believe primitive batteries were used in Iraq and Egypt as early as 200 B.C. for electroplating and precious metal gilding. Around the 1790s, through numerous observations and experiments, Luigi Galvani, an Italian professor of anatomy, caused muscular contraction in a frog by touching its nerves with electrostatically charged metal. Later, he was able to cause muscular contraction by touching the nerve with different metals without a source of electrostatic charge. He concluded that animal tissue contained an innate vital force, which he termed “animal electricity.”

Caveat Emptor

I remember walking to lunch one day back in 2002, in early October, discussing some shootings that had been reported either that morning or the morning before. This was not a normal topic for conversation — shootings in the DC area are not uncommon — but these were sniper attacks and not taking place in the “bad” sections of town. After news of a few more attacks rolled in, there was a palpable sense of uneasiness that began to permeate the area, rising to out-and-out fear. People, including myself, changed their behavior about going out in public areas; I remember putting off getting gas until I could go to a station where I would be on the inboard side of the pumps and not present myself as a target to someone who might be hiding across the street. A few days later, an FBI employee was shot at a Home Depot parking lot a block or so away from that station — a store in a mall I frequent, and within walking distance of my abode (this has been empirically determined, repeatedly). I’ve stood in that lot, and often drive by the lot across the street where the snipers’ car must have parked.

It doesn’t much matter that the odds of getting shot were small. Fear is a raw emotion. When pitted against rational thought, it’s a good bet that fear is going to win, even if the level of fear is not rational. John Allen Muhammad and Lee Boyd Malvo terrorized the people of the greater DC area for three weeks and killed ten people. Today, Muhammed is scheduled to die, and barring an intervention by the governor, he will. I’m not generally a supporter of the death penalty; I think it’s handed out too freely and I have a hard time reconciling it with the notion of a civilized society. But today, Muhammed is scheduled to die, and I find that I have no problem with that.

The Wind in Spain Blows Mainly on the Plain

Spain reaches new wind record: 45.1% of Spain’s total electricity demand

That’s a peak value.

On average throughout the year, wind energy meets 12% of Spain’s electricity demand. The largest producer of wind power in Spain is Iberdrola, with 27 percent of capacity, followed by Acciona on 16 percent and Endesa with 10 percent. Spain’s wind farms are on track to meet a government target of 20,000 MW in capacity by 2010.

Spain’s so lucky, having those large wind deposits. If only we had wind here in the US (that’s not counting the coastal wind, dangerous to harvest off of Nantucket, because of the danger it might spill)

Betty Crocker vs Sally Science

A few years back, during the holidays, I was asked to help out one of my nieces with a small science project. She had to read a book and come up with an experiment based on something in the book, and I was a logical choice to guide her in this endeavor.

And then I was told that baking something would count as a science project, which elicited a mental face-palm. Baking is not science. I pointed out to some of the assembled friends and family that science is about quantifying things — making a measurement.

“You measure things when you bake. A cup of flour, a teaspoon of salt, etc.”

OK, let’s try again: science is about quantifying a prediction, and measuring a result. And that has to be a little more involved than “if I measure these things and follow the recipe, cupcakes will result.” I’m not sure if I got through.

I avoided further controversy by finding a passage in the book where someone observed that a barrel of water froze, and the ice expanded. Aha! That’s a prediction (albeit a general one) and we can measure the expansion of ice. We measured the volume of some water, froze it, and measure the increase in volume by immersing the ice cubes in some cold water in a measuring cup, so there was a discussion of Archimedes principle in there as well. And we got an answer of about 10% expansion. Good enough for grade-/middle-school science.

But things I read keep bringing me back to this: following a recipe is not science. Memorization is not science. They are useful tools for doing science, but individually they are just that, tools. If you want to use baking as an example of science, make a quantifiable prediction and test it. What happens if you change ingredients? Does it matter if you mix the flour and sugar together before adding the eggs and butter? Why? There might be some chemistry there — that gets you started down the path of scientific inquiry.

There’s a section of Surely You’re Joking, Mr. Feynman where Feynman tells about teaching while on sabbatical, and how the students had memorized everything. If you asked the right question, you got a great answer. But when you went off-script, you got nothing, because the students didn’t understand what the words meant and what the definitions implied. It was like memorizing a bit of text in a foreign language, and speaking it perfectly, but having no idea of the meaning of what you just said.

One practical reason that following a recipe or rote memorization does not qualify as science is this: in any reasonably complicated experiment, something will go wrong, and it’s the job of the scientist to figure out why and track down where the problem is. Because there is cause and effect, you can diagnose what signals (or a lack thereof) mean, and uniquely identify a problem. Sometime you build that into the apparatus (e.g. this warning light turns on when that signal gets too big or small, or a needle will go into the red-line area if a bird drops a baguette into your exhaust fan), but for a lot of table-top apparatus it’s a matter of twiddling knobs and isolating individual components. It’s frustrating to have to track down these problems, but ultimately rewarding (to me, anyway) to figure out the puzzle.

Here’s a recent, small example: I was setting up a spectroscopy layout; we had tried this before and couldn’t make it work well enough to suit us, but a newer paper had come out explaining a trick or two we hadn’t considered. I set it up according to the drawing in the paper, and got a funny (funny unexpected, not funny ha-ha) result. Up to that point, I was following a recipe — split up a beam of light with a polarizing beamsplitter, and send them through a vapor cell to do saturated absorption spectroscopy, and modulate one of the beams. But when I adjusted the angle of the half-wave plate (which should have controlled how much light goes into each polarization path), I couldn’t get one of the beams to go to zero intensity, as it should have, and that’s where the science comes in: there was a problem with the polarization. Was the light somehow elliptically polarized? That could be from a bad waveplate. Was it the laser itself, or the optical isolator at the output? Was it the beamsplitter or another piece of optics? That’s where the science came into play. It turns out that the beamsplitter was made for a different wavelength had been put into the wrong drawer, and was always reflecting some light, even when it should have had 100% transmission. Problem solved. By Science™!