Baseball Physics

If you've been watching the NLCS on TV, you've been able to see what a high-speed camera does for the physics of baseball. You get to see how the bat dramatically slows down when it hits the ball -- the illusion of a smooth swing is gone forever. You also get to see how the bat deforms and wobbles after impact. Very cool!

Note to Slipglass: Your CEO is a Genius

Look! It's another genius who thinks "the existence of life refutes the Second Law of Thermodynamics". It's Mark Baisley, who is the CEO of a company called "Slipglass".

And everywhere we look, physicists are scurrying around trying to repair physics after Baisley's devastating refutation.

A Compass Puzzle

So I'm here for a week in Australia at the memorial conference for Alf van der Poorten.

I can tell it's really Australia because they are selling Kellogg's "Rice Bubbles" in the supermarket instead of Rice Krispies.

But there's another way to tell that it's the Southern Hemisphere, since I have a compass with me. Can you figure out what it is?

Some Unimpressive Numerology

The fine-structure constant α is a fundamental constant in physics, and is currently estimated to be approximately .0072973525376.

The physicist Arthur Eddington, who became rather eccentric and believed he could compute the number of protons in the universe accurately, thought it was equal to exactly 1/137, but our current estimate gives something closer to 1/137.03599967899.

The mathematician James Gilson seems to think that α is given by the rather complicated formula (29/π)*cos(π/137)*tan(π/(137*29)). But this is just numerology, and not even particularly impressive numerology. The trick is that tan(x) is very close to x when x is small, and cos(x) is very close to 1 when x is small. So Gilson's formula is just (29/π) times something that is very close to π/(137*29), with an additional fudge factor of something that's very close to 1 thrown in. There is no real surprise, then, that one can find small integers to make this close to α.

Heck, it's obvious that the real value of the fine structure constant is actually 250/34259. Or maybe (cos(2 π/57) - sin(4 π/47))/100? I can't decide which.

Strange Physics Foundation

Take a look at the website for the Santilli Foundation and the International Committee on Scientific Ethics and Accountability. Strange, aren't they?

I particularly liked the reference to "moist insidious and organized plagiarisms".

Roger Penrose is Much Smarter than I Am. But...

Roger Penrose is much smarter than I am. But I think he is completely wrong when he says

In my view the conscious brain does not act according to classical physics. It doesn’t even act according to conventional quantum mechanics. It acts according to a theory we don’t yet have. This is being a bit big-headed, but I think it’s a little bit like William Harvey’s discovery of the circulation of blood. He worked out that it had to circulate, but the veins and arteries just peter out, so how could the blood get through from one to the other? And he said, “Well, it must be tiny little tubes there, and we can’t see them, but they must be there.” Nobody believed it for some time. So I’m still hoping to find something like that—some structure that preserves coherence, because I believe it ought to be there.

We don't have any evidence at all that brains don't follow physical theories.

Fun With a Geiger Counter

A surprising number of household objects are radioactive, and you can verify this with a cheap geiger counter, available on ebay for less than $100. (But be sure you get a geiger counter, not a radiation survey meter. The latter is good only after a nuclear attack, and is not sensitive enough for the experiment I describe here.)

One of the most surprising, at least to me, is water softener pellets -- more precisely, the kind that are made of postassium chloride (KCl). A 20 kg bag (below) sells for about $10 at your local supermarket or hardware store.


Here's a picture of my smallest geiger counter in an empty tupperware container. As you can see, it's registering 12 microRoentgen per hour. Probably most of this background radiation comes from cosmic rays or the smoke detector in my study.


Now I load up the tupperware container with about 1 kilogram of potassium chloride pellets, and try again:


Now the geiger counter is registering 40 microRoentgen per hour. It's not very radioactive, but it is about 2.3 times background.

Why are these water softener pellets radioactive? Surprisingly, it's just due to the potassium content. About 1 in every 8500 potassium atoms is K-40, a radioactive isotope of potassium (and the one that is used in potassium-argon dating). The half-life of K-40 is about 1.3 billion years, which means that potassium-argon dating can be used to date very old rocks (see Dalrymple, The Age of the Earth). K-40 emits both beta particles and gamma rays..

Now, your body also contains potassium, about 140g worth for the average person. So are people radioactive? Yes, slightly. According to this table, potassium-40 accounts for most of the self-irradiation of the body, with carbon-14 a close second. Altogether, about 8000 atoms a second are decomposing inside your body, and this can be measured with a sensitive detector.

Other radioactive items you might find in your house include smoke detectors (some use Americium-241), mantles for gas camping lights (some use Thorium oxide to make the light brighter, although this is less common now), and vaseline glass (uranium is added to the glass to get the yellow color).