Photo Journal

Day 1: Tuesday, 11/1/05

            We spent the majority of today setting up our experiment.  We ran into a lot of trouble getting our laser to hit the sensor correctly.  We had to position the laser just right, and the littlest disturbance could stop the trigger from operating.  Also, we had to adjust the delay unit to trigger the flash at the right time.  The final problem we encountered today was how to clean up our area.  Once the food was taken out of the liquid nitrogen, it instantly started thawing.  So, cleaning up thousands of scattered orange bits posed a big problem.  Our solution was to borrow the robotic lab’s vacuum cleaner to suck up all the juicy fruit bits.  We also learned how to obtain the liquid nitrogen from the Chemistry floor, and used a dewar to contain it.  After everything was set up and working, we took our first and only photograph of the day (right).

Day 2: Thursday, 11/3/05

            Our goal today was to take as many photographs of as many different kinds of foods as possible.  Upon raiding the PFM, we were able to use rolls, ice cream cones, and pears.  However, we spent a large amount of time readjusting the laser and cleaning up the food from the previous photograph.  Also, we discovered that we would have to take more than one trip to the Chemistry floor, and the liquid nitrogen boiled away quickly.  Also, we found that these solid objects did not break well, so we were forced to throw them at the ground instead of dropping them to get a significant shattering effect.  The photograph to the left is of a pear that was thrown at the ground instead of being dropped.

Day 3: Friday, 11/4/05

            Today, we continued to take photographs of shattering foods.  We wanted some variation of photographs, because oranges and rolls were admittedly getting boring.  We obtained some sliced red peppers, lettuce leaves, and cherry tomatoes from the bountiful PFM.  After fiddling with the precarious photogate for yet another time, we were ready to take photos.  We poured some more liquid nitrogen into our dewar and dropped most of the tomatoes and some lettuce in.  The tomatoes have very thin skin, so as soon as they froze enough to shatter, they would cleanly split in half.  Therefore, we were left with only the oranges and other food from yesterday, as well as the lettuce and peppers.  We got some nice photographs of shattering lettuce, although we first had to change the delay.  Since a leaf is flat and has a lot of surface area, it falls slower than a round object, such as an orange.  Because of this, the delay we had set yesterday was insufficient for the lettuce (right).  Also, we had to adjust the delay again for the peppers.

Day 4: Tuesday, 11/8/05

            Today, we took Dr. Winter’s advice, and added a second flash to our set-up.  The second flash is used to eliminate harsh shadows on the side opposite the first flash.  By setting up the two flashes the same distance, pointing at the subject from the same angle, we effectively canceled out the harsh shadows.  The lighting and exposure in the  photographs we took using this method were significantly better than past pictures, as you can see to the left.  Today, we also used different foods.  These, contrary to the title of the experiment, were not from the PFM.  We photographed shattering broccoli and whole green peppers, which were interesting, as peppers are hollow.  We hoped to also photograph shattering sweet potatoes, as well as another pepper, but time ran out before we had a chance to.