In the tradition of physicists through the ages, I've attempted to make a very simple model of a complex system.

This image is screen shot from a game that simulates some of the feedback issues involved in sex. It's the Physics of Sex equivalent of a spherical cow.

To play the game, you have to stimulate the floating ball with your mouse. If you do it properly, the meter on the left will show your progress. Ultimately the meter will top out and the ball will turn red and throb. I'm not going to tell you exactly how to stimulate the ball. Just like learning about the birds and bees in real life, you'll have to discover some of the details on your own. Also just like real life, it's not that hard to figure out.

If you want to give it a try, click the image to download the Widget file. If you've never installed a Widget before, you'll first have to install the free Yahoo Widget 4 engine. It should work automatically on a Mac.

The game is a bit simple and not too challenging at the lower levels(although I haven't beaten it at Level 12 yet), but it illustrates three things about sex

1. Positive feedback (provided by the level meter) helps you achieve the ultimate goal.

2. Negative feedback is necessary to help you follow the ball and apply the appropriate stimulation at the apprpriate place. That is, when the mouse cursor is too far from the ball you adjust by bringing it back.

3. The simplified orgasms simulated by playing the game, which I claim are similar to the type that men have most of the time and women have at least some of the time, are essentially the result of integrate-and-fire circuits.

The first two points are probably familiar to most folks, but integrate-and-fire circuits are a bit more obscure. Basically, this type of circuit measures some input and when it reaches a trigger point it fires.

Avalanches look a lot like integrate-and-fire circuits - snow builds and builds on a mountain until it's unstable, then the slightest disturbance can send it caree...