Taking a Look at Clouds From Both Sides

Got your head in the clouds? Well, why not?

It’s hard to imagine a more interesting place to be. In fact, it’s hard to imagine just where you could be in the universe and not be in the clouds.

Even familiar clouds are among the few phenomena that truly qualify as incredible. In “Science From Your Airplane Window,” crystallographer Elizabeth Wood writes, “Suppose you had the task of trying to make [a] blind person believe [in] them.” Suppose, indeed!

Floating on thin air like foam on cappuccino, a good-size cumulus easily can weigh 500,000 pounds. Yet for all their bulk, clouds are easily the most “uninhibited of all natural phenomena,” wrote the late Guy Murchie in “Song of the Sky.” “Nothing in physical shape is too fantastic for them.”

That’s because clouds are wind made visible, skywriters that pen their messages in tiny drops of water (or sometimes ice), telling the world below (and also above) where currents are rising, racing and colliding.

Clouds, as Murchie so aptly put it, are “the architecture of moving air.”

Not all of a cloud is necessarily visible. The curly crown of a cumulus is only the very top of a tall cloud tower that reaches clear down to the Earth; air heated on the ground puffs up and rises, eventually cooling enough for the water held inside to condense. The cloud itself is but the ice cream perched on a long, invisible cone.

The creation of that high-flying ball of fluff is curiously similar to what happens in the kitchen to a kernel of corn sitting in hot oil. But then again, what is popcorn but bite-size clouds?

For that matter, what is a dandelion but a cloud of fluff? My daughter’s cat but a cloud of orange fur? Down pillows but clouds of feathers? An actress’ puffy lips but a cloud of collagen? Smoke, insects and perfume all make their way around the world in clouds.

Even an atom is but the tiniest nut of a nucleus entirely engulfed by a cloud of electrons. Until recently, physicists even hunted down elusive subatomic particles by watching for the wakes they left in cloud chambers.

There are clouds everywhere we look, and even some places we’d perhaps prefer not to. Computer pioneer Alan Kay, creator of many of the computer interfaces we now take for granted, recently described the problem of talking with your computer in terms of “thought clouds.”

“When you say something to somebody, you’re actually pointing to something in your thought cloud that you hope is in the other person’s thought cloud too,” he said. The problem is, people have trouble connecting with a computer’s thought cloud (and, of course, a computer doesn’t have a thought cloud until a person puts it there). The use of windows that appear and disappear, Kay said, made it possible “to put the computer’s thought cloud on display.” Using a mouse, he said, is “literally how you point to your computer’s thought cloud.”

If that isn’t spacey enough for you, consider space itself, which easily is the cloudiest realm in the cosmos. Stars turn on in clouds, and also die in them--sometimes leaving behind garishly glowing nebulae (yet another word for cloud). A star that dies in a massive explosion is a cosmic-scale cloudburst.

Other nebulae forever remain dark, littering the galaxy. Astronomer Steve Maran, in “Astronomy for Dummies,” calls these dark nebulae “the dust bunnies of the Milky Way.”

A galaxy is a cloud composed of stars instead of drops of water. In fact, the two sidekick galaxies of the Milky Way aren’t even called galaxies, but rather the Large and Small Magellanic Clouds. Jupiter’s famous bands really are stripes of pastel-colored clouds. A few years ago, a group of astronomers even announced they had discovered a huge cloud of antimatter hovering over the center of the galaxy.

It’s hard to imagine how clouds got such a bad name--dismissed by some as so much fluff, cursed by others as foreboding.

But clouds do have a dark side, of course, figuratively as well as literally.

For example, it is clouds more than any other single factor that obscure the current understanding of global climate change. Some clouds act like beach umbrellas, keeping the planet shady and cool; others are like blankets that hold heat in. Which will dominate in a warming climate? No one knows.

Those thick, curly cumulus--no doubt, the “marshmallow clouds” songwriter John Lennon had in mind--reflect most of the sun’s light back into space. When you see them from an airplane, Wood points out, the tops are white. Even from the ground, you can sometimes see the sunshine leaking over the edges, giving even dark clouds a silvery fringe.

So clouds really do have silver linings. Only it’s on top.