Remembrance of Physics Experiments Past…

A heavy camera to hold...

The human mind is certainly remarkable in its ability to retain long term dormant memories.
I've been reading the book "For the love of Physics" which is the autobiography of the physicist Walter Lewin. (cover shown at left)  I've also been watching several videos of him delivering lectures on physics to undergraduate students at MIT. I majored in physics in college, so there was an element of faint recollection watching him explain the basic principles of mechanics, especially the motion of a pendulum.
I recently purchased an old Polaroid camera at a thrift shop (see image at right). Fooling around with the camera brought back memories of a physics experiment that I did in college where I documented the movement of a double pendulum by making time lapse exposures with a Polaroid camera. What startled me was being able to recall this activity from 45 years ago that I had not thought about in 45 years! It's like this memory had remained dormant for 45 years, awaiting only the proper stimulus (reading Dr. Lewin’s book and fooling about with the camera) to return it to my conscious thinking.

Visualizing “rainbows” in ice on the surface of a pond.

This image was created by photographing the ice on the surface of a pond. The patterns displayed here are not visible to the naked eye. They become visible when the camera’s lens is equipped with a polarizing filter that only allows light to reach the film that was reflected by the ice at one particular angle of polarization. To enhance the color contrasts of the polarized light, air was injected under the surface of the ice. This air layer, besides adding to the aesthetic interest of the images,causes more of the light incident on the ice layer to be reflected back to the surface, rather then being transmitted through the ice layer into the water underneath. Other images created using this same technique can be viewed here
Abstract Ice composition