There is nothing more primitively satisfying that scratching an itch. Babies, dogs, monkeys and people with crabs do it like their lives depend on it. It's one bodily function that you don't have to work hard to accomplish, and you don't have to agonize over the consequences or make any kind of decision beyond the simple brain-to-hand order "scratch." For most of us, scratching an itch is a simple endeavor that gives an immediate reward: itch relief.
Yeeeeaaaah, that's the spot.
But for people with certain skin, immune system and psychological ailments, scratching is a whole other compulsive and painful ball of wax. For doctors, one of the most baffling symptoms a patient can report is unexplained itching. How are you supposed to treat something like that when, up until recently, nobody had any clue how scratching relieves an itch?
What We Just Found Out
Here's a shocker: It's not your skin that's making you itch, nor is it your skin that's getting relief when you scratch. All of that itching and scratching business is controlled by a specific set of neurons in the spinal cord. Here's the six-step experiment that scientists used to figure out what's behind your urge to scratch the dozens of itches that this paragraph has made you suddenly aware of all over your body:
Step 1: Paralyze and sedate some monkeys.
Step 2: Put electrodes on their spinal nerves.
Step 3: Inject monkey legs with histamine to give them the itches.
Step 4: Watch monkey spinal neurons fire up; dance a little jig for the fun of it.
Step 5: Scratch monkey legs, but not in the same place the histamine was injected.
Step 6: Observe the calming down of monkey spinal neurons.
Step 6(a): High-five someone.
Maybe throw in a little crazy for good measure.
Did you catch that? They made the monkeys itch in once place -- say, their little monkey knees -- then scratched them (with a sciencey metal scratching device) in an altogether different spot -- let's say their monkey butts. And according to their monkey spines, the misplaced scratch did the trick.
Obviously, this is huge news for the world's population of sleeping paralyzed monkeys, but it could also mean a lot of relief for a lot of itchy people who doctors decided were crazy when they couldn't find the poison ivy that was making them scratch holes in their skin.
Trying to explain the difference between cats and dogs is like trying to explain the difference between a hamburger and a double homicide. Cats are so haughty and mysterious that we've put them on a fancy pedestal of elegance, while dogs are pretty much the George Wendts of the animal kingdom. If you met a talking dog in a bar, you'd probably buy him a beer and ask him to tell you his life story. If you met a talking cat, you'd probably start speaking with a British accent and "harumphing" so he would stop judging you.
And you still wouldn't be good enough.
Added to the mystery is the fact that until recently, no one quite understood how cats drink. In fact, no one really thought much about it and just assumed that cats drank like dogs -- using their tongues to form a kind of backward cup. Watch:
Kind of a convoluted way of wetting your whistle, but, hey, whatever floats your boats, dogs. Like most animals, cats lack the capacity to suck past infancy, but unlike dogs, they can't quite work their tongues into ad hoc cups. But what they've got going on is whole lot cooler.
What We Just Found Out
Every time a cat gets a drink, it's doing complex physics with its mouth.
Here's how it works: First the cat dips its little kitty tongue into the water, then it whips it back, pulling up a column of liquid with it. Just before gravity draws its watery prey back to the bowl, KA-CLOMP! Garfield snaps that airborne drink into his chops.
And they can get four laps in a second. So unless your eyes have the power to slow down time (in which case, you should really be playing Major League Baseball and watching less cat drinking), you really can't be blamed for missing the mystery.
The coolest part, besides the ka-clompage, is that cats are hard-wired to calculate exactly when they can catch the most water. If they snap too soon, they'll get just a drip, but if they wait too long, they'll get a swallow of nothing, because the water will already be back in the bowl. Scientists actually made a robocat tongue machine to measure how fast a cat should lap to get the most water. But it was too late, because the cats were already lapping at that exact speed.
For years, science has explained the formation of glaciers using the "layer-cake growth model for ice sheets," because they know we won't pay attention to illustrations that aren't either shiny or delicious. The theory is based on the assumption that glaciers grew from the top down, like a layer cake. Snow fell and froze to the top of the glacier, making it bigger and heavier and pushing more of it underwater.
And they are delicious.
For as long as humans have known about glaciers, we've thought they formed from this top-down process. It wasn't just an excuse for scientists to envision the Arctic as one massive coconut layer cake. The model is responsible for all that neat stuff you learned about ice ages in the past, and it also helps scientists build their glacial melt models. You know, the ones predicting when all the coastal cities need to call it a day.
What We Just Found Out
There's more than one way to build a glacier! Yes, the accumulation of falling snow is one way, and it's perfectly fine, if you're into that sort of thing. But the other way is from the bottom up. In the spring of 2011, scientists found out that liquid water under glaciers can actually freeze and thaw, depending on the insulation and friction from the ice above. The refrozen ice not only can constitute half of the thickness of some glaciers but also can violently change their landscapes, as you can imagine would happen when a glacier is taking a piggyback ride on a flowing river of water that suddenly solidifies.
And that's when it gets pissed off.
So if we went back to the coconut-layer-cake analogy, it would be like the baker deciding to add icing and cake to the top and bottom layers, maybe while wearing roller skates, because he's a wild card.
So what does this mean to us? It means our glacier ice-melt models are shot. Because if the top layer of melting ice is getting replaced by an invisible (to us) bottom layer of solidifying ice, how are we going to predict the glacier's thickness? And did we mention that it takes "aircraft equipped with ice penetrating radars, laser ranging systems, gravity meters and magnetometers" to find this subglacial refreeze ice party in the first place? So it's not like we can just check out Google Earth to see what's shaking at the poles. It's also ruined all of our ice-dating methodologies. We can't count on the top layer being new and the bottom layer being old when refrozen ice is screwing and warping all the layers above it. Everything we understand about ice ages and climate change comes from correctly dating that ice -- something we just can't do anymore.
Dude. Not cool.
But hey, at least we've got that whole ozone hole figured out, right? Right? Science? Why are you coughing uncomfortably and staring at your shoelaces? Crap.
Kristi Harrison is an editor here. And you can follow her on Twitter here.
For more ways scientists aren't as good at their jobs as you'd expect, check out 6 Insane Discoveries That Science Can't Explain and 6 Creepy Animal Behaviors That Science Can't Explain.