Have you been to the gas station this week? Of course you have. So, while pumping gas and staring at the price sign, you've undoubtedly noticed how much the price of gas has soared not only in this week but in general over recent years. Gasoline, which has been the main source of fuel for the majority of years in the car's history, is becoming more and more expensive and, from my point of view and the environments standpoint, grossly impractical. These factors are leading car manufacturers to develop cars fueled by alternative energies. Two hybrid cars took to the road in 2000, and in three or four years fuel-cell-powered cars will most likely roll onto the world's highways.

But instead, would you like a car that runs on air?

Like I do! We wouldn't poison the atmosphere and we would actually help to clean up air pollution. Sounds too good to be true, but that's what researchers at the University of Washington are trying to develop. Expanding on a concept that has been tried before and abandoned, the researchers have even built a crude prototype of a car like this one, on top of the frame of an old mail carrier.

Just such a car, Nitro, is the brainchild of Abe Hertzberg, professor emeritus of aeronautics and astronautics at the university, who heads up "project smogmobile," and has named the car after the L'il Abner cartoon car that runs on air pollution. The contraption doesn't quite run on "air" but it comes pretty close. It runs on nitrogen, which makes up 78 percent of our atmosphere, and it could turn out to be a viable substitute to gasoline-powered vehicles of today and the electric-powered cars now being mandated by some states, especially California.

Funded by a $360,000 grant from the U.S. Department of Energy, the researchers took an ancient "air motor" and converted it to run on nitrogen. They mounted it in an old mail truck and "it ran the first time we took it out of the shop," Hertzberg says. About 25 people have already ridden around the block a few times."

How Does It Work?

Simple! Nitrogen gas is extracted from the atmosphere and super cooled to -320 degrees Fahrenheit, at which point it converts into a liquid. The liquid nitrogen is then pumped through a heat exchanger, like the radiator in a conventional car does, which uses heat already present in the atmosphere to warm it up enough for the liquid to vaporize. As it converts from liquid to gas, the nitrogen expands to 700 times the volume of its liquid form. The expanding gas pushes on a piston in the "air motor," forcing it to move. That is similar to the process that drives an internal combustion engine-gas vapors are ignited and expand rapidly, pushing a piston down and turning a crankshaft that propels the vehicle.

For the testing phase the research team needed to find an "air motor" that used compressed air to drive the pistons. The best they could come up with was a relic from the past-a 1941 anchor winch that weighed 600 pounds and was in such poor condition that it had to be rebuilt. Eventually it worked, but it only produced about 15 horsepower. Still it was enough to verify their concept, making it at least better than electric cars, which, Hertzberg says, are inefficient, inconvenient, and not nearly as environmentally friendly as they are alleged to be. Batteries have to be recharged, for example, increasing the demands on power plants, and they use toxic metals that have to be carefully disposed of.

"At least if you spill liquid nitrogen, it just sits there in a pool and slowly evaporates back into the atmosphere from where it came."

But I ain't waitin' for you humans to catch up on "air energy locomotion". I'm outta he're.