November 18th, 2006


[/.] Bussard talks Fusors.

(A miniature proto-sun blossoms to life, throwing out streams of plasma, in the core of a fusor.)

George Bussard gave a talk at Google and it's been posted to Google Video. He talks about research he's been doing into fusors, devices which can be made into electrostatic confinement based fusion reactors. Though at present, apparently not ones that produce more energy than they consume. So while it's not without its flaws, it's pretty cool stuff anyway. The video is an hour and a half, so if you have anything else to do with your afternoon you should probably skip it. But if you have time to kill, it's a fun watch.

Bussard seems to be failing where Tokamaks are also failing - with respect to the magnetic confinement problem. But to his credit, the fusor approach just seems a lot more intelligent and less brute-force than the way Tokamaks do things. I was also going "buh?" to myself when he talked about using gas centrifuging as part of the reactor's fuel filter. It's true what he says about it being a straight-forward process. But a single person painting the Empire State Building by themselves is also a straight-forward process. People often make the mistake of thinking that "straight-forward" implies "fast" and/or "easy."

[Reddit] Free online Basics of Electronics e-book.

A noteworthy observation may be made here. As each electron moves uniformly through a conductor, it pushes on the one ahead of it, such that all the electrons move together as a group. The starting and stopping of electron flow through the length of a conductive path is virtually instantaneous from one end of a conductor to the other, even though the motion of each electron may be very slow. An approximate analogy is that of a tube filled end-to-end with marbles:

The tube is full of marbles, just as a conductor is full of free electrons ready to be moved by an outside influence. If a single marble is suddenly inserted into this full tube on the left-hand side, another marble will immediately try to exit the tube on the right. Even though each marble only traveled a short distance, the transfer of motion through the tube is virtually instantaneous from the left end to the right end, no matter how long the tube is. With electricity, the overall effect from one end of a conductor to the other happens at the speed of light: a swift 186,000 miles per second! Each individual electron, though, travels through the conductor at a much slower pace.

I haven't gotten into the later sections, but it looks pretty good from the first few chapters.