Experimental Method

List of Equipment:

• Motionscope high speed motion picture camera

• glass nowl

• tap water

• wine glass

• skim milk

• Sony miniDV camera

• Separation Funnel

• Quartz studio light

• Frosted plexiglass

• Kodak Carousel 4400 slide projector

Equipment Setup:

Description of Setup:

    The dropper was set approximately two meters from the ground.  The glass bowl or wine glass full of tap water or skim milk was then placed on the floor.  We lit the milk with a quartz stage light from the side.  The water was lit from behind with a slide projector filtered by two pieces of translucent plexiglass.  The Motionscope high speed motion picture camera was then placed one meter from the bowl of water.  The Sony miniDV camera was set about one and a half meters away from the bowl while filming.

Description of triggering, timing, and imaging methods:

    Since we were using the Motionscope high speed motion picture camera, the triggering and timing were all done manually.  When the drop began to fall, we began recording, and we stopped after the event had taken place.  We then exported the captured image to the Sony miniDV camera.  In order to take high quality pictures, we had to use a backlighting system that consisted of a slide projector that shone through two pieces of frosted plexiglass.  We placed the bowl of liquid between the motion picture camera and the Plexiglas, so the bowl appeared to be lit from behind in the pictures.  The specific distances in our setup are as follows: distance from dropper to pool of water, 2 meters, camera distance, 1meter, distance from light to water, .3 meters.

    The main goal of our experiment was to capture images of bubble formation  from a drop then analyze it.  In analysis we wanted to find what factors contribute to bubble formation.  From Worthignton’s book we found that height, size of drop, and oscillation of drop.  From these starting points and some preliminary photographs we decided to experiment with two variables, height and surface area of the pool that the bubble was to be dropped into.  Worthington tells us that the higher distance that a bubble is dropped from, the more spherical it will become.  We decided to use water as our medium, because milk did not allow us to have an under the surface view, and more bubbles where produced with the water.  Therefore it was a better substance for testing.  In our second photo shoot we left the height the same, the full 2 meters, to make sure that we would have a greater chance of bubble formation, and then changed the surface are.  We did so by using both a wide rimmed glass bowl and a small rimmed wine glass.  The difference in surface area was quite large.  As we hypothesized the wine glass did not produce as many bubbles even though the drops where dropped from the same distance as that of the larger glass bowl.  After we analyzed these qualities we went back and looked at the shaped of drops before entry to the water.  We found that if the drop was oblong or flat before it hit the water, then the bubble did not form ever, but when it was spherical it almost always formed a bubble.  Through this analysis we were able to corroborate what Worthington had previously reported.