Discovering Solar: It’s a Radiometer, I Wanted a Magic 8-Ball

Posted in Bob Higgins at Clean Technica, Humor, Science by Bob Higgins on August 14, 2011

One year they gave me a Crookes Radiometer I wanted a Magic 8-Ball

When I was a kid my parents were big on educational toys. Most Christmases, in addition to a new bike or other barely affordable extravagance, I could expect to find, surrounded by a detestable pile of new socks and underwear, an erector set or a chemistry set, a microscope perhaps and a couple of dime store curiosities like the device pictured at left.

I don’t remember much about that long ago Christmas morning when I unwrapped the Crookes radiometer. I do remember that I was fascinated by it and still am today. It sat on my desk or window sill for a year or so until shattered by one of my brothers. Which brother was the culprit has never been determined but I’m still on the case.

At the time it was a quiet, inexpensive, solitary treat for a geeky 8 year old. To watch the gizmo respond when I switched a desk lamp on and off or spin wildly when I placed it in direct sunlight and wondered about light and heat, atoms and the mysterious forces that surrounded me was better than TV. These were the days of the Indian Chief test pattern, there wasn’t much on.

Thinking about it this morning I couldn’t remember what the gadget was called and had to search for solar powered toys and solar vanes until I discovered with amusement that the Crookes radiometer has its own Wikipedia page.

Originally posted at Clean Technica: Discovering Solar: It’s a Radiometer, I Wanted a Magic 8-Ball

What got me started on this reverie was a New York Times story about a guy who collected uranium, radium and americium in an attempt to satisfy his curiosity about nuclear fission by reproducing it in his kitchen in Angelholm, Sweden.

I thought that was impressive, my early chemistry experiments succeeded only in stinking up the house, but Richard Handl managed to blow up his stove and get arrested in his quest to advance human knowledge. But after all he was thirty one.

For years, in truth, until this morning, I would have said that the rotation of the radiometer’s vanes was caused by the pressure differential of the photons reflecting or being absorbed by the dark or light colored vanes. I was wrong, then and now.

It seems that Crooke and James Clerk Maxwell would have backed my theory back in 1873 but physics wizards like Lebedev and even Einstein got involved and disproved the photon pressure thing to Maxwell’s satisfaction but never described exactly what causes the motion. Read the Wiki article, it’s enjoyable.

I’m glad in a way that the mystery that fascinated me so long ago remains largely unsolved. I remember once fantasizing about building giant versions of this light mill to drill holes or drive turbines but I think performing work on that scale is far beyond the realm. It’s nice though to find that the device may be doing some useful work as a tiny heat engine for use in medicine.

I don’t know if this describes the effects of educational toys on the impressionable minds of 8 year old boys or the limits of scientific genius in the late nineteenth and twentieth centuries but I’m in the market for another radiometer and when I break this cold case I’m going to make the culprit pay for it.

In the meantime I’m setting up the kitchen for cold fusion. I’m going to stack salami, cappacola, peppers, onion and cheese together on some fresh bread and see if the resulting fusion results in enough energy to mow the lawn.

Bob Higgins

Originally posted at Clean Technica: Discovering Solar: It’s a Radiometer, I Wanted a Magic 8-Ball