Eyes and light filters

[quarter450]

Hi,

 

I was looking at experiment and I was wondering if somebody here could help clarify my understanding of it. I plan on presenting it to my class.

 

It has to do with a pendulum and light filter for one eye (sunglasses).

 

What you do is get friend to swing pendulum (side to side) about 2 meters away. Cover one eye with the filter and look at the swinging, instead of going side-to-side, it should be turning in an elipse. If you switch filters side over to the other eye, the pendulum elipse is swinging in the other direction.

 

How come?

 

I know it has to do with delayed reception of one eye (one w/ filter)vs other eye and then brain connecting the two together which causes the circle to appear, but I don't understand how it changes directions when you switch eyes.

 

Can somebody explain that to me please.

 

Thanks,

 

Bryan

[swansont]

Apparently it's called the Pulfrich effect.

 

http://en.wikipedia.org/wiki/Pulfrich_effect

 

http://www.photo-3d.info/wiki/Pulfrich_Effect

 

 

 

edit: OK, I just set this up and tried it, and I gotta say it's pretty cool.