Interesting Stuff

As more details come out, it looks like I was spot-on last night in my analysis of the embassy bombing in Athens. Hot damn!

It turns out one of my coworkers used to work for Evolution Robotics, which made the ER1 I used in my robotics research a year and a half ago. It’s nice to know that he agrees with me that the ER1 could have been a great product except the basic software, power converter, and marketing department were crap (though apparently if we had sprung for the $1,000 software it would have worked better). Intriguingly, he also thinks that adding a laptop and camera to a Roomba is a good way to get a cheap robot, which is what Prof. Dodds is doing now (he was my robotics research prof). Nifty!

For several weeks, I have been pondering the following: speakers and microphones are pretty much the same, in that they’re both bits of piezoelectric material held next to magnets with wires coming out of both sides. The only difference is that current is imposed on one and the other imposes itself on the current instead. Consequently, it seems like you could take your headphones and use them as really crappy microphones to record sound wherever you go with an MP3 player, assuming you made the correct changes to the firmware. Well, it turns out that not only is this possible, but people have already done it. In true hacker form, the first step is to install Linux on your iPod. I don’t think I’m actually going to do this in the foreseeable future, but it’s nice to know that someone else has tried it and it works.

I read a copy of the Federal Flag Code today, and was rather puzzled by parts of it. According to section 4,

• The flag should never be used as a receptacle for receiving, holding, carrying or delivering anything.
• The flag should never be used for advertising purposes in any manner whatsoever. It should not be embroidered on such articles as cushions or handkerchiefs and the like, printed or otherwise impressed on paper napkins or boxes or anything that is designed for temporary use and discard.
• No part of the flag should ever be used as a costume or athletic uniform.
• The Flag, when it is in such condition that it is no longer a fitting emblem for display, should be destroyed in a dignified way, preferably by burning.

However, I see such things all the time: President Reagan’s funeral, flag paraphernalia, and Captain America are three examples that leap to mind, though I admit that the last one is a slight stretch. Perhaps Uncle Sam would be a better instance of a costume. That fourth part, about burning flags, seems to be under considerable resistance at the moment.

What is going on here? On one side, we have people who want to pass laws to keep the flag dignified and undesecrated. On the other side, we have such a code already in place and being blatantly ignored by the people on the first side. Does anyone have any insight into why this is happening?

Yesterday, I got to see a live video feed of Steve Wozniak talking about his youth and how he cofounded Apple Computers. A summary of the talk →

1. My can of soup says to put in a bowl, cover loosely, microwave, and then let stand for a minute. I do all of this in a plastic bowl with a flimsy plastic lid that can be sealed shut (but I don’t seal it). When I take the soup out of the microwave, the lid is not only sealed on, but bowed in from lack of pressure (lack of atmosphere?) inside the bowl. The soup is still hot (I don’t think it has cooled much). What’s going on?
2. My shower has a smooth, clear, glass door. When I shower, the water covers it with a smooth, even layer, so I can still see out pretty clearly. When I touch my finger to the glass, the water “runs away” from my finger and leaves the glass nearly dry in the vicinity. This is so strong that the water will actually flow up to “escape” my finger’s vicinity. New drops of water that hit the glass while my finger is touching it also move away (though at a slower pace, since they can’t flow as easily without more water around). When I remove my finger, the film of water returns to the way it was before. This isn’t dependent on something I’ve put on my finger; it works with all 10 fingers/thumbs, both elbows, my tongue, and at least one toe. I don’t have a water softener. What is happening?
3. Galileo showed that all objects fall at the same rate, no matter how much they weigh. I have a bowl full of Cheerios and put some raisins on top. The Cheerios and raisins are about the same size, but the raisins are denser. I put my hand over the top of the bowl and shake it. I would expect all objects in the bowl to fall at the same rate when I shake, and keep the raisins on top. Instead, they gradually migrate towards the bottom. What’s going on?
4. There is a doorway with the sun shining through it onto a wall (with the shadow of the doorframe on the wall). I stand several feet in front of the door so that the side of my shadow nearly touches the side of the door’s shadow. The part of my shadow closest to the door’s is mirrored, so it appears that the side of my arm is coming out of the doorframe. This occurs even if I move around slightly (it appears as though the door’s arm is moving in the opposite direction). The shadows need to be within a couple inches of each other to get this to work. What is going on?

The world is a strange and fascinating place.

My frisbee claims it is 175 grams, but it certainly doesn’t feel like the regulation weight. Consequently, I wanted to weigh it. The problem? I don’t have a scale. However, I have a bathtub, a whiteboard marker, a large bowl, and a bottle that claims to hold 237 ml. I fill the bathtub partway, and put the bowl in it. I fill up the bottle and pour it into the bowl, and then mark on the bowl where the level of the bathtub water is. I empty the bowl, put the frisbee in it, and mark the height of the water on the bowl again. I take the frisbee out of the bowl, and mark the height of the bathtub water on the bowl when it’s empty. I then take the bowl out of the water and measure the distances between the 3 marks. The distance from the bottom mark to the top mark should denote a volume of 237 ml. The distance from the bottom mark to the middle mark should indicate the volume of water whose weight equals that of the frisbee. After a little algebra, I decided that my frisbee weighs roughly 200 +/- 50 grams. I guess it may very well be labelled correctly.