90ways - Science

With ANWR's recent demise, the globe's continual warming and spring's hesitant arrival here in the northeast, I though I'd speak a word in appreciation of ice, and specifically in favor of the miracle that is ice skating. Over the last several years there has been a revolution in the way we understand the physics of ice skating. Ice is slippery; we've always known that. But it's kind of funny to think that you can use skate blades to both push yourself forward on the ice and to glide along it at the same time. How come, as you try to glide, your skates don't just bite into the ice and stop you in your tracks? Or how come when you push, you don't just slip?

For a long time scientists figured we could skate because the pressure of your skate blades would melt the very top layer of the ice as you stood on it (ice is able to stay water at temperatures lower than 32 degrees under conditions of extreme pressure). The thin layer of water that would be created on the surface of the ice lubricates your movement and allows you to slide merrily along. Yet recent advances in the field of 'surface dynamics' have shown that neither skates nor pucks nor curling stones can put enough pressure on ice to instantly melt it without having the ice crack.

Professor Gabor Somorjai, who, by the way, spends his time doing experiments with ice in sunny Berkeley California, is the godfather of modern surface chemistry. He recently discovered that ice has a 'quasi-fluid layer' sitting at its surface at all times, not just under significant pressure or friction. As with many things in chemistry, the party responsible for this unexpected discovery is called entropy. Favorite concept of quasi-scientists and political philosophers the world over, entropy is the measure of the disorder present in a system. Everything we've ever experienced in the entire universe happens in such a way as to increase the overall entropy (or disorder) of a system.

As it turns out, the most entropically favorable way for ice to form is for it to maintain a super thin layer of liquid water on its surface at all times. Because the structure of ice is very orderly and the structure of air is very disorderly, it makes the system as a whole happier for there to be an intermediate step - in this case, slightly disordered liquid water - acting as a buffer between the two.

This new understanding of the physics behind ice skating has had profound effects, especially if you plan to build a rink and skate on the moon any time soon. Under the old regime, skating on the moon (or many other celestial bodies) would have been impossible because the temperature of the ice there would have been too cold for it to thaw, even under the most intense pressure conditions. Now that we know that the Laws of the Universe demand there always be a very thin layer of liquid water on the surface of ice, we can happily skate away on the Sea of Tranquility.

The term "undiscovered species" often conjures brazilian rain forests full of exotic medicinal herbs and deep ocean caverns populated by strange glowing sulfur breathing organisms. Not so for the latest entry to our world's ever growing database of living things -- scientists found this one roasted on a stick in a market in Laos. The animal is locally referred to as Kha-nyou, loosely translated as "rock rat", and was only classified with a scientific name this past April.

Particularly notable is the fact that the little rock rat is actually the first member of a new family of rodents. In case anyone had forgotten that Kittens Pounce Clumsily On Furry Green Spiders, Family is the third rung up the taxonomic ladder. While the discovery of a new species is a common occurrence, its been over 30 years since a new mammalian family has entered the books. In other words, the morphology of the rock rat is different enough from all other rodents to require an entirely new designation.

Taxonomists use a variety of characteristics in arranging organisms into their different sub-groupings. For example, every member in the Phylum Chordata is distinguished by displaying a backbone like structure during embryological development. When you get down to classifying members of Order Rodentia, you're dealing with a narrower set of traits like tail bushiness and skull shape. The rock rat has a thick tail and long head, and although it looks like a cross between a rat and a squirrel, it actually is most closely related to the guinea pig. After long consideration, Kha-nyou's qualities necessitated the creation of Family Laonastidae and as the taxonomic gods feasted, King Arthur rested his sword on each shoulder of the small rodent, welcoming it into the scientific community and bestowing it the new name Laonastes aenigmamus. Huzah!