 So here we are in the lab room with a setup for the parallax lab. Now just to give you a better view of what's going on here, here at the front of the table we have two sticks that are separated by a known distance, and then we have a measuring tape down so that we can place our other stick at a very specific distance. So right now it's set at 50 centimeters. And then further down the table we have a stand which has a meter stick on it. So the idea here is that depending on where you're looking at it the position of that center stick seems to shift back and forth relative to that meter stick. So you're going to see a series of images which have a little bit zoomed in so it's easier to read the meter stick. But what the students do is they get down here on the level and they move their eye back and forth closing one eye until the stick that's right in front of them and the stick that's further down the table are exactly on top of each other. And then they zoom in on that meter stick behind it and figure out what's its position back there. Okay so this is the physical setup and what they're doing and then they move over to the other stick and they'll repeat the same sort of thing. Now it's really hard to get my camera to hold still here and this is where in the lab they're able to help each other out a little bit. But you'll be looking at some images which show the positions for the left side and the right side for each position distance down the tape.