Showing posts from December, 2007

Black Swans

Science can't prove anything. No watter how much evidence may exist that something is so, it only takes one counter example to show that it isn't. But that's not a weakness of science, it's the way things work. Our unwillingess to accept it is a weakness in the way we think.

In 17th century Europe the only swans anyone had ever seen were white. In fact, "all swans are white" was used as the standard example of a scientific truth—until 1697, when explorers found Cygnus atratus in Australia— black swans. Here's one I photographed in New Zealand.

The fact is, as Francis Bacon warned, our minds are wired to deceive us. "Beware the fallacies into which undisciplined thinkers most easily fall--they are the real distorting prisms of human nature."

Assuming there's more order in nature than is actually there is something that crops up frequently—faces in clouds, figures in tree bark and peanut-butter, even religious explanations for natural processes…

The Claus That Refreshes

Really, St. Nicholas didn't celebrate Christmas and probably never saw, or knew about, reindeer because he lived in what's now Turkey. The Dutch legend Sinterklaas traveled on a gray horse and wore bishop's robes.

Thomas Nast is generally credited with “inventing” the image popularly recognized as Santa Claus when he first drew him for the 1862 Christmas season Harper’s Weekly cover to memorialize the family sacrifices during the Civil War. But Nast’s Santa was not a "jolly old elf", rather he was melancholy, sad for the separation of soldiers and families.

In any event, the idea that Nast “invented” Santa Claus overlooks the centuries-long antecedents to his invention.

In 1823, for example, a more cheerful fellow was depicted in an anonymous poem entitled, "A Visit from St. Nicholas" (now popularly known as "The Night Before Christmas"). The poem appeared in a Troy, New York newspaper depicting Santa as a jolly fellow who rode in a sleigh drawn…

A Different Angle on A Solar Eclipse

NASA's Solar Terrestrial Relations Observatory (aka STEREO) has a pair of satellites in orbit that can take pictures of the Sun simultaneously from different angles, providing a 3D view of our nearest star.

As it turns out, there are times when the Moon passes between the Sun and one of the spacecraft, and from STEREO’s angle it's an unusal view.

From the Earth, the Sun is about 400 times farther away than the Moon, but it's also about 400 times bigger than the Moon so the Sun and Moon are about the same apparent size in the sky. When there's a solar eclipse the Moon slides in front of the Sun, just barely (some times not quite) covering it.

For STEREO the Moon appears much smaller than we see it, but the Sun is still at about the same distance so the Moon appears a lot smaller than the Sun.

Not long after STEREO's launch the Moon passed directly in front of the Sun as seen from one of the spacecraft, and STEREO caught it, and now you can see it too.

You lose most body heat through your head

A well known clothing manufacturer (can't tell you their name, but their initials are REI) claims that you lose 75% of your body heat through your head. They sell hats, you might guess. A wetsuit manufacturer claims you should wear a rubber hood because you lose 80% of your body heat through your head. Don't try it on the subway, but it might help some in the water.

Think about it, though, if all that was true you could get naked, put on a hat, and be warmer! Research is under way...

According to Guyton & Hall's Textbook of Medical Physiology, a nude person in dry, calm air loses about 60% of their body heat simply by radiation through their skin. Makes you hot, er...cold, just thinking about it, right?

Actually, you radiate much like a light bulb, but infrared energy, not visible light. In fact, you radiate as much as a 100 watt bulb when you're sitting still. You're even brighter (light-wise) when you exercise, not so much if you have poor circulation.

You lose a…