5The Moon: What's Up With That?
Unless you're a Druid, a poet, a werewolf or some heinous combination of all three, you probably don't spend much time thinking about the moon. We notice when it's there, forget about it when it's hidden and occasionally laugh at the suckers who used to think it was made out of cheese.
Oh, and goths. Goths love them some moon.
Here's the thing, though. Despite the fact that the moon is obviously the closest thing to the Earth in the universe, or that we've been on it, up until fairly recently, we knew surprisingly little about it. Why is one side of the moon pockmarked while the other is smooth? How'd it get there? What's it made of? An annoying-enough person could have argued that the whole cheese theory technically could have been right, and up until recently, scientists would have had to back down. Sure, they had some good guesses, just like we've got guesses as to why starving people have big fat bellies (they're tricking us for sympathy). That doesn't mean they're right.
You dirty, manipulative bastards.
What We Just Found Out
No one has been on the moon for almost 40 years, so it's not like we could just pop up there and start digging and sticking thermometers into its craters. Fortunately, astronauts left seismometers on the moon during the Apollo missions that transmitted moonquake data back to Earth until 1977. Recently, a professor and a graduate student at Arizona State University took those numbers and applied a new method of analysis to them called array processing. By layering seismic recordings together and studying them at the same time, they were able to detect very faint signals they couldn't hear before. Then they used those signals, or "echoes," to map out what was going on beneath the moon's surface using the same techniques geoscientists use to figure out what's going on beneath the Earth's surface. Next, they high-fived each other and screamed, "Bla-DOW! Science!"
Yay! Time to break out the orange juice and people clothes!
The data told Professor Clever and his student minion that the moon has a solid, iron-rich core, just like the Earth's, and that the core is surrounded by a liquid iron outer core, also just like the Earth's. Both the Earth's core and the moon's core are made of iron, nickel and light elements like sulfur.
This is important, because it supports the prevalent theory of how the moon got there, which is that a Mars-size body hit Mother Earth, which chunked Baby Earth fetuses out into space, which eventually accelerated and melded together to make the moon. Sure, it doesn't explain where cheese comes from, but it's a start.
Remember the first time you noticed how your hands got wrinkly when you stayed in the bathtub too long? And how you assumed the wrinkling was caused by an aging curse cast by your neighbor, who was clearly a voodoo queen because she was the only woman in town who wore a turban? And remember how your mom explained that it was sitting in a bathtub for an hour and a half, not black magic, that gave you Shar-Pei hands? Turns out your mom was talking out of her ass.
She was trying to cover a terrible, terrible secret.
Not only did science not completely understand why you got pruney fingers in the bathtub, it didn't know why your skin didn't disintegrate after taking on so much water. This, apparently, was a real conundrum to scientists. They looked at your skin under a microscope, worked up some advanced mathematical models and decided that your skin should just fall apart like crepe paper in the rain every time you take a bath.
What We Just Found Out
Math. Math is under our skin, doing its mathy work, keeping our skin intact and unmelted.
Take a look:
That's a model of a gyroid, which is a geometrical shape found all over the natural world. Mathematicians think that fibers of keratin in our skin are actually woven into this shape as well, which is important, because it means the skin can expand but keep its structure because the fibers have so many connections to one another. With this pattern, the fibers can "swell to fill a volume seven times greater than its original shape."
That's what's happening when your skin wrinkles. It's absorbing water, which makes it grow in volume. Since the rest of your hand is still the same size, your skin begins to wrinkle the same way a glove would if it was too big for your hand. As unnerving as it might be to think that your skin is getting too baggy for the rest of your body, it's better than the alternative.
Most geometric models, when asked to grow in volume, just break up. To illustrate this, try taking a bath in a tub made of corrugated cardboard. Not so easy, is it? That's because unlike your skin, that cardboard is woven together in a gyroidless pattern, which falls apart.
As scientists learn more about gyroids, they might be able to use the pattern for synthetic skin, bandages, bulletproof vests and more weather-resistant housing for the homeless population.