Still-life paintings are nice, but motion is what grabs our attention. Fortunately, nature always obliges: Nothing in the universe is stationary.
They say that the best way to learn about anything is to write a book about it, and that’s what I’ve done with natural motion. And even though I have no shame, it’s too early to plug Zoom, since Little, Brown isn’t putting it out until spring. But here are some cool natural motion facts that I came upon during my year of research.
Start with our own Earth. Did you know that there’s a planet inside our planet? Earth’s core, once believed to be liquid, is now known to be a solid ball the size of the poor demoted planet Pluto. And get this: It spins faster than the rest of our world.
At our planet’s surface, many different motions unfold. Most ocean currents move at walking speed. Superimposed on them, waves proceed at 45 miles per hour, and are spaced about nine seconds apart. But the nature of water only allows them to swell with a one-to-seven ratio of their height to their spacing. When they encounter shallower seabeds, friction slows down the wave’s lower portion while their tops still proceed at the previous speed, thanks to inertia. As a result, the wave’s top increasingly leans forward. When the ocean floor shallows enough to become one-half of the wave’s height, the wave must “break.”
Continents shift, but at variable speeds. The fastest tectonic plate carries the Hawaiian Islands northward at a swift four inches per year. Meanwhile, even when New Yorkers lie in bed, our own plate heads west toward California; we’ve traveled several feet closer to Hollywood since we were kids.
In our bodies, intestinal digestive stuff moves about a foot an hour. Our ideas – neuroelectrical impulses – are a bit swifter, at 250 miles an hour. That’s the speed of thinking. But there are several types of nerve signals, and they proceed at vastly different rates. You know how, when you stub your toe, there’s that agonizing pause of two or three seconds before you feel anything? That’s because certain kinds of pain signals are downright lethargic. The body goes, “That’s the third time he’s stubbed his toe this month. No sense rushing to give him the bad news.”
Air motion is cool, too. History has pretty much forgotten the man who told us why the wind blows, but I spend a chapter on the guy because his life was fascinating. Let me share one relevant factoid: our local winds. They are about to increase. Our average winds from November through April blow significantly stronger than during the warm months. Indeed, our own Northeast region delivered the fastest winds ever observed on Earth’s surface – or at least witnessed by a living human being, rather than an automated machine. It happened atop Mount Washington. The date was way back on April 12, 1934, when they visually measured a sustained wind of 231 miles per hour: not a mere gust, but sustained wind.
That has never been seen before or since. Incidentally, I asked the researchers there how fast the wind must blow before it knocks them off their feet. (They’re very aware of this danger, and all receive blowdown training.) Surprisingly, I got a bunch of different answers, which ranged from 70 miles per hour to twice that.
Apropos of nothing, how about germ speeds? Bacteria, propelling themselves with corkscrewlike flagella, can swim ten times faster than fish, relative to their size. Some germs can move two feet an hour. They could swim clear across a damp countertop while you are watching your favorite TV drama.
Out of room, but I hope that you love this stuff as much as I do. We’ll do more, later this winter. I’ve got a pile of scribbled notes of this stuff.
Want to know more? To read Bob Berman’s previous “Night Sky” columns, visit our Almanac Weekly website at HudsonValleyAlmanacWeekly.com.
Woodstock’s Berman, our longest running columnist, is one of the most widely read astronomers in the world, able to translate complex scientific concepts into language understandable to the casual observer yet meaningful to the most advanced. His dry, edgy wit regularly engages readers of Discover Magazine, Astronomy Magazine and The Old Farmer’s Almanac, and he is the author of seven books.
The Bardavon and a number of community partners have hosted a variety of low-cost or free events as part of SkyFest, including the two visual art exhibitions on view through November 30 at the Barrett Art Center and the Adriance Memorial Library. The Hudson Valley Philharmonic will close SkyFest with a performance of Holst’s The Planets with simultaneous projection of rare NASA/Hubbell Space Telescope images. For more information, visit www.bardavon.org.