## March 21st, 2009

### "No user serviceable parts inside."

When I was in engineering school in the early 1980's they were still interested in teaching some of us about big thick wires hung from aluminum towers you needed helicopters to visit. While my degree was to be in semiconductor physics, a discipline involving things so small everyone is sure magic is involved, I decided I wanted to learn how the other half lived. I wanted to see the great big turbines. The big ball bearings. The megavolts. The multi-Tesla magnets. The big boy toys.

So I took an elective in power generation and distribution systems.

The nice thing about power distribution and generation was the math was absolutely trivial compared to the partial differential world of quantum physics. All the answers involve the square root of two. Most power systems math can be summed this way: take a really big number and multiply by the square root of two. You can use three sometimes, but only when things are totally out of control.

Now that you know the math, you're ready to be an engineer.

For instance, take two really thick copper wires. Bolt them to a big piece of concrete on the floor. Send a couple hundred amps down them at once. The answer about what happens is something times something times the square root of two. It's cool to watch. The bolts fly out of the concrete sending shrapnel everywhere. The wires try to go to opposite ends of the universe, taking the building and everything in their way with them. The smoke fills the lab and sets off the fire alarm. Enough ozone is created by the arcing to replenish the hole over Antarctica. Burning is everywhere.

The professor, who has been in the teacher's lounge the whole time, comes in and sees the lab wrecked and screams something about Lorentz. Then he goes to work in 7-Eleven selling Big Gulps because kids aren't supposed to be left alone with so many amps.

http://everything2.com/index.pl?node_id=1348321

### Next, BattleMechs and Boomers.

A new material that is weight for weight stronger than steel and stiffer than diamond, and weighs little more than its volume in air, could be the perfect artificial muscle for robots.

"We've made a totally new type of artificial muscle that is able to provide performance characteristics that have not previously been obtained," says Ray Baughman, a materials scientist at the University of Texas, Dallas, and co-developer of the new muscle. Baughman and colleagues have developed a technique to make ribbons of tangled nanotubes that expand in width by 220% when a voltage is applied and then return to their normal size once it is removed. The process takes only milliseconds.

Collections of those ribbons could act as artificial muscle fibres – for example, to move the limbs of a walking robot, says Baughman. And the material has other impressive properties. It is extremely stiff and strong in the "long" direction – that in which the nanotubes are aligned – but is as stretchy as rubber across its width. It also maintains its properties over an extreme range of temperatures: from -196 °C, at which temperature nitrogen is liquid, to 1538 °C, above the melting point of iron. This means any robot equipped with the nanotube muscles could potentially keep working in some very extreme environments.