The Internet to the Rescue: Brakelights

I lent my car to my main squeeze. Later that night she called to say that all the brake lights (left, right, and high mount) would not go off. She tried pulling the fuses, but that didn't work. I suggested that she just pull the battery cable, but she didn't feel up to doing that in the night. It took a call to AAA in the morning for her to get started.

Being ever resourceful, when she got back, she searched the web to find the brake wiring diagram on about.com which seemed to show that the brake light switch was the culprit. Some more searches and I had a decent idea where to find the switch and what to do on answers.yahoo.com. (Being who I am, there was an interlude to notify all-parts.com that they'd misspelled "Cadillac" as "Caddillac".) With her watching the rear lights we determined that two thicknesses of a postcard were all that separated the switch indicating the brake being on or off. My guiding principle in this regard is to ask myself, "What would Bob do?", Bob being a fellow graduate student with a firm idea of quality workmanship, integrity, and what slapdash fix would hold until the cavalry arrived.

I didn't have the necessary open end wrenches so I wrapped the brake pedal lever with the necessary cardboard and went looking for a sale on open end wrenches. My usual source for cheap tools (tools I can lend or lose without getting upset), National Wholesale Liquidators, closed it's stores in my area due to the credit crunch and there doesn't seem to an obvious replacement.

Stay tuned.

Stats Update

One of the stats profs dropped by for something else and I managed to inveigle him into analyzing a particular set of stats. It looked to me as if there was a difference between accredited departments and those which weren't. Sure enough a Chi-square showed significance way out to the p=.0001 level.

What was interesting because I don't yet understand it was that calculating Chi-square using a spreadsheet was half the value generated by SPSS. The stats prof said it was because of the way Chi-Square stats treat a 2x2 matrix. Beyond me, but I passed the good news along to the prof who wanted to find something significant to say about her survey.

Only later I found that "significance" is not as significant as it once was: statisticians seem to prefer describing confidence levels rather than specifying the probability of significance.

My Favorite Porn - I

Watching math videos is a rarefied perversion, but a fascinating one none the less. The poster child is BottemasTheorem. The theorem is simple to state: Draw squares on AB and BC on two sides of the triangle ABC. Let R and S be the points on the squares opposite vertex B. Then the midpoint M of RS is independent of B.

The setup looks like this:
The point labeled M does not move regardless of how the red triangle is changed. Mathematica's Demonstration site shows the deformed triangle (below) but the understanding of the theorem conveyed by the triptych is nothing compared to the impression of the online demo.

Click on any of the images to go to the site and start the animation.

The mathematicians who stumble onto the Mathematica are mesmerized by the demos until the need to tap a kidney bring them back to reality.

If math doesn't attract you, you still might want to take a look. Measuring the Speed of Light with Marshmallows is fascinating even for mathphobes.

Enjoy.