oh yes, it will be mine....

one of my co-workers recently purchased a VW phaeton and drove it to work to show off. this is a $80,000+ vehicle. VW built a special factory in germany to build only this car. one of the 10 million bells and whistles in this thing is the automatic windshield wipers. the windshield senses rain and turns on your wipers for you automatically. it also vaires the speed of the wipers depending on how much rain is on your windshield. i tried to figure out how this worked for several days. i finally decided that it is black magic.

the question popped back into my head again this morning and i finally gave in to the power of google. turns out it is simple physics.

PHYSICS LESSON KIDS!!!!

there is a transmitter/sensor behind the rearview mirror, atttached to the windshield that spews out infrared beams at a 45 degree angle into the glass. glass has a refractive index of 1.50, water has a refractive index of 1.33, air has a refractive index of 1.00029. therefore, the infrared light angle gets changed when there is water adjacent to the glass as opposed to air. the sensor reads the change in reflection angle and operates the wipers accordingly. the more water on the windshield, the more beams get changed, etc.

whats even better is that this system can be retro-fitted into any car for as little as $150. you can buy them here:

kick ass wiper controls sytem!!!!!!