First off, how cool is the sign on our lab door?
(not the fire extinguisher part)
Lab 2's materials are at these links:
Lab 2A - Optical Table Fundamentals and Component Placement
Physics 492 Self-Assessmment
For convenient downloading you'll need a free Google account. Google is not evil, just demanding.
The class was about the table and putting components on it. We started by getting used to working in gloves with our tools and building up some simple mount bases, then placing them at assigned locations. We finished with full builds of several beam splitters from parts still in their wrappers. A quick design conference between the two teams divided up the table and reached agreements on where beamsplitters will go to provide beam distribution to three separate experiment areas. Here is one of the beam launchers at its assigned location, performing its function. Can you see a piece of Doug?
What, you may ask, is the white and blue stuff? The white is some lens tissue that came with the beamsplitter in its box being used as a compliant load-bearing surface for the beamsplitter to sit on. The tissue in turn is taped down with some small cut pieces of blue painter's tape to keep it from moving as the glass is placed. We don't want metal to touch glass if we can avoid it. Without the paper, the glass would sit right on the anodized aluminum shelf, and very high stresses would be developed at the three (why three?) contact points, leading to microscopic damage. But the paper is compliant - it deforms somewhat - so the load through the glass to the shelf is distributed over some area. It is easy enough to protect the glass in this way (this time!) and a good habit to always be thinking about how the glass is being touched. The beamsplitter cube is held in place by a nylon-tipped set screw threaded through the upper shelf which compresses it against the tissue paper. This set screw must be only snug and not turned down tightly - again to avoid possible damage to the glass.
The layout design conference was an exercise in parallel coordinated work by the two teams. We don't have time (nor inclination necessarily) for everyone to do everything. We need to do some parallel processing. In this case each of the two teams sent 2 representatives to the whiteboard to agree on how to divide the table up and arrange how beams would be delivered to several experiment areas with the beamsplitters. The result:
Lab 3 prep package will be up shortly. Part of the prep will be to watch one of Feynmann's videos. The video itself is over an hour long, so be sure to schedule some time for this. The video is online and streams to your computer like YouTube. Also there will be a narrative with questions for you to work related to the video.
Next week we'll take a little time exploring the concepts in the video and relate them to what is happening on the tabletop.
