December 2003 Archives
Amazon Lists are a good way to discover new music. I just found this great IDM list. I think I own about half the albums on that list, so our tastes match up fairly well. I ended up ordering Pause from Four Tet, Audiotacker from Mouse on Mars, and Tides from Arovane. All Music corroborates Greg's picks, and I've had good luck following their suggestions in the past. Amazon doesn't stock Tides, so I ordered it from Forced Exposure. They seem to have a lot of harder to find stuff, so I picked up a couple other albums, too.
How many times have your heard that it's not the volts that'll kill you, but the amps? While mostly true (it takes only 100mA to stop your heart), amps and volts are eternally bound together by Ohm's Law:
V = IR
In plain English: volts (V) equals current (I) times resistance (R). So, assuming resistance is constant, voltage and current are in lockstep. As one goes up, so does the other, and vice versa. You can't have a lot of amps without a lot of volts.
So, back to which kills you, the amps or volts. Given your body is a constant resistance, it really is a combination of both. Higher voltage means higher amperage, and thus higher voltage has more potential to kill. It takes only 100mA to stop your heart. I believe the resistance of a person with dry skin is somewhere around 100,000 ohms. This means, even touching 120V is far from lethal. The probem is wet skin is around 1,000 ohms, and the inside of your body is even lower, thus making 120V potentially lethal. OSHA actually has a good page describing this (even if they resize your damn browser window). And here's another explanation of the biological effects of electric shock.
You also, of course, have to take the power supply into account. All power supplies, especially batteries, are far from ideal. As they supply current, the voltage drops. A standard 1.5V AA battery cannot source 1A for any sustained period of time (if at all), for example. That's what makes a 12V car battery a lot more powerful, than, say, 8 AA batteries. I sincerely doubt you could start your car with a pack of Duracells.
BTW, even a standard 9V battery can kill you. Don't believe me? It's happened in the Navy. And I've seen that story before, so I think it is actually true.
I also think that many people are injured or killed, not necessarily from direct contact with an electric shock, but the aftershock. For example, a television tube usually runs at somewhere around 20,000 volts. But, it doesn't have a lot of current capability. The voltage drops off quickly as it discharges (i.e. you touch it). So, even though the shock is not lethal, the involuntary muscle contractions can cause you to touch something else more dangerous. Perhaps something inside the TV (like the power supply), or maybe it'll through you off your chair and into something sharp in your workspace. Either way, the potential for injury is still significant.
Anyhow, that ends my rant on weather amps or volts will kill you. The truth of the matter is they are both dangerous in the right quantities and situation. So be careful around electricity!
Ok, it's official. I can't stand Jakarta's Commons Logging. It's causing me all sorts of class loader problems with its stupid discovery process. I really wish every project using Commons Logging would switch over to log4j. log4j kicks butt over every other logging packing, including JDK 1.4 logging, so I see no reason not to just use it by default. I mean, if you're going to bother to add another dependency to your project, you may as well make it log4j. I know all my projects will.
Update: The author of log4j has written a deeper description of the problem. I have experienced the moving of jar files at random, and it is not fun.
DIANE SAWYER: But stated as a hard fact, that there were weapons of mass destruction as opposed to the possibility that he could move to acquire those weapons still —
PRESIDENT BUSH: So what's the difference?
Mr. President the difference is, well, um, nevermind.... *hits head against wall*
It's only Monday, and already it's one of those weeks were everything goes wrong. First, my car needs $1k in repair, then my furnace needs a $200 part, for a total of $250. I guess that's my "gift" to myself this year. Too bad... I would have really loved a TiVo. Ah well, it could always be worse.... but now I have a case of the Monday's.
Oh, how I hate
target="_blank" in HTML links. Page designers, please stop opening new windows for me. I can decide that for myself, thank you very much.