Bad Astronomy. Misconceptions and Misuses Revealed, from Astrology to the Moon Landing 'Hoax'

detailed shape of your drain than from the rotating Earth.

Obsessive would-be physicists have actually performed experiments using household sinks. They have found that the sink needs to sit still for over three weeks so that random currents die off enough to see an appreciable Coriolis effect. Not only that, they have to let the sink drain one drip at a time to give the effect time to take hold. You’re not likely to see this after hand-washing your delicates in the sink.

The same is true for your toilet. This one always makes me laugh: toilets are designed to spin the water. It helps remove, well, stubborn things that don’t want to be removed so easily. The water is injected into the bowl through tubes that are angled, so it always flushes the same way! If I were to rip my toilet out of the wall and fly it down to Australia, it would flush in the same direction it does now.

The idea that the Coriolis effect works on such small scales is a pernicious myth. I have seen it in countless television shows and magazine articles; it was once even reported in the Sports Illustrated swimsuit issue. Oddly, they describe walking across the equator from the Central American country of Costa Rica, which is hundreds of kilometers from the equator. Some writer on staff did the figures incorrectly, but then, those aren’t the kind of figures the magazine is usually trying to sell. On the other hand, maybe all that walking is how the models stay so slim.

So, if the Coriolis effect doesn’t work on something as small as a sink or a pan, how did Peter McLeary pull it off? After all, as Michael Palin commented, it worked for him.

Actually, McLeary cheated. If you watch him do it on Pole to Pole, you can catch the swindle. He stands on his equator line and fills the basin. Then he walks a few meters or so north, and rapidly turns to his right to face his audience. He opens a hole in the bottom of the pan and the water obligingly rotates clockwise as it drains out. Next, he refills it, walks a few meters south of the equator, then rapidly turns to his left to face the audience. Draining, the water spins counterclockwise.

Do you see how this works? By spinning rapidly in opposite directions, he can make the water rotate any way he wants! The squarish shape of the pan helps, too; the corners help push on the water as the pan rotates, making it flow better.

Meteorology professor Alistair Fraser has used this demonstration in his own class. He draws a line down the middle of the classroom and declares it to be the equator (he teaches in Pennsylvania).

He then does just what McLeary does and gets the same results.

Still don’t believe me? Then think about it: the Coriolis effect should make draining water spin counterclockwise in the northern hemisphere and clockwise in the southern. In the northern hemisphere, water moving north deflects east, moving it counterclockwise.

Water coming south from the north deflects west, but that’s still counterclockwise. The opposite is true again for the southern hemisphere; the water will spin clockwise.

But this is precisely the opposite of what McLeary demonstrates. He’s a fraud!

Your honor, I rest my case.

Well, not really. I have one more tale to tell. While searching for information about Nanyuki, I found one tourist’s travelogue that describes three sinks sitting roughly ten meters apart, just outside of town. One is south of the equator, the second is directly on it, and the third is north of it. Perhaps someone else is horning in on McLeary’s act. Anyway, the tourist who wrote the travelogue claimed that the northern sink drained clockwise, the southern sink drained counterclockwise, and the one in the middle drained straight down. Evidently the drain holes have been cut in such a way as to force the water to drain the way the designer wanted. Note once again that they drain the wrong way!

It’s pretty funny, actually. They go through all that trouble to make a few bucks, and they don’t even get the scam right. Somehow, though, I don’t think those con artists are starving. Con artists rarely do. They can always put the right spin on their subjects.

3. Idiom’s Delight: Bad Astronomy in Everyday Language

Light-years ahead

One of the reasons I loved astronomy when I was a kid was because of the big numbers involved. Even the nearest astronomical object, the Moon, was 400,000 kilometers away! I would cloister myself in my room with a pencil and paper, and painstakingly convert that number into all kinds of different units like feet, inches, centimeters, and millimeters. It was fun, even though it branded me as a geek. That’s all changed, of course. As an adult I use a computer to be a geek a million times faster than I ever could when I was a kid.

The fun really was in the big numbers. Unfortunately, the numbers get too big too fast. Venus, the nearest planet to the Earth, never gets closer than 42 million kilometers from us. The Sun is 150,000,000 (150 million) kilometers away on an average day, and Pluto is about 6,000,000,000 (6 billion) kilometers away. The nearest star to the Sun that we know of, Proxima Centauri, is a whopping 40,000,000,000,000 (40 trillion) kilometers away! Try converting that to centimeters. You’ll need a lot of zeros.

There is a way around using such unwieldy numbers. Compare these two measurements: (1) I am 17,780,000,000 Angstroms tall. (2) I am 1.78 meters tall. Clearly (2) is a much better way to express my height. An Angstrom is a truly dinky unit: 100 million of them would fit across a single centimeter. Angstroms are used to measure the sizes of atoms and the wavelengths of light, and they are too awkward to use for anything else.

The point is that you can make things easy on yourself if you change your unit to something appropriate for the distances involved. In astronomy there aren’t too many units that big! But there is one that’s pretty convenient. Light! Light travels very fast, so fast that no one could accurately measure its speed until the nineteenth century. We now know it travels about 300,000 kilometers every second. That’s a million times the speed of sound! No wonder no one could measure it until recently.

So, astronomers use light itself as a big unit. It took the Apollo astronauts 3 days to go to the Moon in their slowpoke capsule, but it takes a beam of light just 1.3 seconds to zip through the same trip. So we say the Moon is 1.3 light-seconds away. Light takes 8 minutes to reach the Sun; the Sun is 8 light-minutes away. Distant Pluto is about 6 light-hours away.

A light-minute or -hour may be useful for solar system work, but it’s small potatoes on the scale of our Galaxy. Light doesn’t travel far enough in only one minute. For galactic work, you need a light- year, the distance a beam of light travels in one year. It’s equal to about 10 trillion kilometers, which is a long way. Proxima Centauri is 4.2 light-years away; the light leaving a presidential inauguration might not reach Proxima Centauri until after the president leaves office at the end of the term!

The light-year is the standard yardstick of astronomers. The problem is that pesky word “year.” If you’re not familiar with the term, you might think it’s a time unit like an hour or a day. Worse, since it’s an astronomical term, people think it’s a really long time, like it’s a lot of years. It isn’t. It’s a distance.

That doesn’t stop its misuse. The phrase “light-years ahead” is a common advertising slogan used to represent how advanced a product is, as if it’s way ahead of its time.

I can picture some advertising executive meeting with his team, telling them that saying their product is “years more advanced than the competition” just doesn’t cut it. One member of the ad team timidly raises a hand and says, “How about if we say ‘lightyears’ instead?” It sounds good, I’ll admit. But it’s wrong. And more bad astronomy is born.

Worse, one Internet service provider even claims it’s “light-years faster than a regular connection.” They’re using it as a speed!

Not surprisingly, Hollywood is a real offender here. In the first Star Wars movie, for example, Han Solo brags to Obi Wan Kenobi and Luke Skywalker that he could make the Kessel Run in “less than twelve parsecs.” Like a light-year, a parsec is another unit of distance used by astronomers; it’s equal to 3.26 light-years (that may sound like a silly unit, but it’s actually based on an angular measure using the size of the Earth’s orbit). Han’s claim is like runners saying that they run a 10-kilometer race in 8 kilometers! It doesn’t make sense. Astute fans of Star Wars may notice that Obi Wan gets a pained look on his face