The number of Salsa dancers in Seattle who are engineers is staggering. Maybe it's the linear approach to teaching that is employed by most Salsa instructors or maybe its the challenge to do something non-linear in nature that appeals to these linear thinkers. Whatever the source of their fascination, I think the linear approach to dance can easily be taken too far. Ballroom dancing may be a good example of that. It is certainly true that my favorite dancers are the most non-linear thinkers I know of. Anyway, despite my predilection for reductionism and linear thought in general, I was stunned when I was directed to one geek's categorization of Salsa dance moves [Phil's Salsa Step List][via SalsaFix]. Good luck trying to learn Salsa like that. 10:52:39 AM      

An Australian engineer has invented "an underwater jet engine" that is capable of generating 30 horsepower of force in a device that is only 20 centimeters long. If that weren't enough, it is powered by the tried and true workhorse of the industrial age, steam [NewScientist].

The Pursuit Marine Drive produces thrust by using the energy from high-pressure steam to draw in water through an intake at the front and expel it at high speed through the rear. The steam emerges at high speed from a rearward-facing ring-shaped nozzle into a cone-shaped chamber, where it mixes with the water (see graphic). Shock waves created as the steam condenses are focused by the chamber to blast water out of the back.

This is a good example of how something can seem completely obvious after it is invented, yet no one came up with it sooner. How is it possible that the concept of the jet-engine-in-water was not developed and deployed by the U.S. military during the Cold War? The airplane was displaced by the jet-plane because jet engines produce a lot more thrust than prop engines. With the "underwater jet engine," we can expect a similar displacement for water craft. Yet despite the similarities, this engine has emerged in 2003 instead of 1963.

As I read the article, one drawback did come to mind. The concept of turbine engines for cars has been around for a while, but it never caught on. Turbine engines operate in much the same way as jet engines and are able to produce a large amount of work in a very efficient manner. However, unlike conventional internal combustion engines, you have to wait a couple of minutes for them to rev up before you can actually drive away. Car users find that to be an unacceptable trade-off. We want to turn the ignition key and immediately speed away.

For a steam powered water jet to function, it needs steam. Unless you can find a way to generate steam almost instantaneously the moment that the ignition is turned on, these water jets will succumb to the same weakness that has hampered the introduction of turbine engines in cars. However, that won't stop the water jet engine from being introduced into other more specialized applications like ferry boats and other craft that operate continuously for large stretches of time.

The New Scientist article mentions a number of other benefits and uses of this steam powered jet. It has a number of excellent properties and, assuming there are no major technical barriers, it is likely that we will be seeing these engines in all kinds of applications in the near future. 10:21:49 AM