Archive for April, 2009

Faster Sailboats

Monday, April 20th, 2009

I may never have been on a sailboat in my life, but I am fascinated by the physics behind their operation. They must operate simultaneously in two mediums, as both an airfoil and a hydrofoil. Plus, they are probably one of the “greenest” vehicles ever conceived.

Which makes you wonder why we don’t use them more.

Not only are they dependent on the weather, but they are also considerably slower than an airplane. I’ve been thinking about how to make them faster, and my inspiration came from a book about airplanes – The Deltoid Pumpkin Seed by John McPhee. This book documents, in popular language, the experiences of a group of entrepreneurs and engineers to build a hybrid airplane/airship (the Aereon) that would have a small engine and use helium to improve its lift characteristics.

Why not do the same thing with a sailboat? Especially since most of the drag comes from the “wetted hull”, it would make sense to lift the hull out of the water as much as possible and leave only the keel submerged. Ship designers have been doing this for years with cleaver hull designs intended to lift themselves out of the water as they get up to speed, but the Aereon design suggests another way – helium.

What seems to make sense to me would be to build a trimaran and fill the outriggers with helium.

Cold Fusion

Tuesday, April 7th, 2009

A friend of mine recently bent my ear for an evening over cold fusion. It struck me as pseudo-science, but not wanted to be prejudiced, I spent some time with a web browser looking into it.

Though I still have a hard time believing some of these claims, I have to admit that this technology shows promise.

The Coulomb barrier that must be overcome to fuse two protons is about 5 MeV – not something you’d expect at room temperature, but well within the range of a standard particle accelerator. The problem is the minute cross section of the nucleus – protons with enough energy to fuse are far more likely to be scattered away from each other unless they are precisely aligned in a head-on collision.

That’s where the cold fusion claims start to get interesting. All of the cold fusion reports that I read involved palladium as a catalyst. Now palladium has the unusual property that it can absorb significant quantities of hydrogen. There doesn’t seem to be a consensus on exactly how this works, but one explanation is that the hydrogen nuclei can move fairly freely within the palladium crystal mesh. Now if I wanted to line something up at atomic dimensions, a crystal would be the obvious choice, and if I wanted to line something up while its moving, then I would want a crystal that allowed my particle mobility. So palladium seems like an obvious choice to line up moving protons to precisely collide them.

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