Trebuchet

Jake had a "catapult project" for science class. They were challenged to build catapults for launching tennis balls as far as possible. The rules stipulated that they couldn't use any kits or prefabricated pieces, and that the catapult must fit within a 2x2x2 ft area, with the vertically extended catapult arm no higher than 2 ft. Because the project allowed incorporating something like a non-rigid sling, which could operate outside the 2x2x2 area, we decided to pursue such a design; technically making our catapult a "trebuchet".

This video shows the trebuchet being fired in our backyard after we finally got it working. The technically keen will likely notice that launching angle is not optimal -- its actually launching the ball downward. Jake chose not to pursue any further "tuning", so this is the best it got- which was still quite satisfying for us. Jake's favorite part of the project was creating graffiti to adorn his machine, which he spray-painted onto the side of the trebuchet. Jake's graffiti reads:

Cum catapultae proscriptae erunt
tum soli proscripti catapultas habebunt

This roughly translates as: When catapults are outlawed, only outlaws will have catapults

Brain exploration

Yesterday, as a paid guinea pig (40$/2hr), I submitted myself to lying motionless in a MRI tunnel of the UCSB Brain Imaging Center. The almost 2 million dollar machine creates a magnet field of about 3 tesla (T). This is unusually strong! To give you a relative sense, the strongest magnetic force you might have around your house would probably be the coil gap of a typical loudspeaker magnet which is 1 T to 2.4 T. A rare earth magnet (like (Nd2Fe14B) neodymium-iron-boron) is rated at 1.25 T.
Despite going into it with the attitude that I'd be able to do well putting up with the confined space and gadgetry, the MRI procedure was quite annoying. My biggest complaint is that the bed they make you lie on with your head clamped in a special box, is not wide enough! My arms would hang off the sides, and when in the tunnel they were pressed against the hard walls - making them eventually fall asleep, which was a problem because I was supposed to be motionless (so couldn't do much to wake them back up). Then there were itches on my nose which I couldn't tend to... The experience became some sort of torturous challenge of self-control, as I attempted to focus on the boring experiment and ignore my discomforts. The experiment consisted of me looking at a computer screen (via a mirror) which had a tiny circle that turned either yellow or blue. Yellow was supposed to mean difficult, and blue easy... at least 84% of the time. I was to press buttons with my index or middle finger to indicate whether I detected an X or N in a quickly flashed array of letters arching above the colored circle. I had to respond within one second of the letters flashing on the screen and disapeering. And I had to do this over and over and over for almost two hours. The point of the experiment, as it was explained to me, was to see how these color cues helped the subject better prepare and respond to the tasks - and I guess they were going to back the response data with brain image data.

I'm never doing it again. It was one of those things like jumping out of a plane -- that is a great thing to do once, but then once you've done it, there isn't much point to going through it again.

The best thing that came out of the experience, though, is that I got 192 images, of slices of my head. Checking out these images on my computer made me feel like I had just crossed a border into a whole new frontier of exploration - my brain! Wow! The supercomputer with circuitry which has yet to be understood by the best of us.

Anyway, using my MRI images (and some other stuff collected on my computer, I put together a video montage. In order to fit it to the Sun Ra song "Stardust for Tomorrow" - its shown twice. enjoy