High-speed projectiles, breaking glass, and hot plates were used in some of the projects. These required that safety procedures be observed in order to avoid injury to the experimenters and damage to the equipment. Those who want to attempt similar experiments should only do so under responsible, adult supervision.
"Burst of a Water Balloon" -- JoLynn Funk, 1995
The flash unit discharged twice as the water balloon was being punctured, once during the puncture and again as the water flooded the table. JoLynn took this photograph as part of a 4H-sponsored course in high-speed imaging at the Edgerton Explorit Center. She is an 8th grader at Walnut Middle School in Grand Island, Nebraska."Collapsing Water Drop" -- Jason Martin, 1991
A falling water drop takes on a layered appearance as it collides with a solid surface. The drop did not splatter, because it was released from only a few centimeters above the surface. Jason took the photograph as part of a study to compare various collision systems. He found interesting similarities between the collisions of water drops and those of racquetballs."Halving a Tennis Ball" -- Amoz Eckerson, 1995
A sound trigger located just below the racket was used to capture this tennis ball in mid-collision with the racket. The distortions of both the ball and the strings of the racket are made evident by the protrusion of the flattened side of the ball behind the racket. Amoz is a sophomore at Aurora High School. He works as a volunteer, building and maintaining exhibits at the Edgerton Explorit Center."Striking a Match with a BB" -- Brian Yen, 1993
A BB, fired from right-to-left, grazed the tip of this match. The BB's image, seen as a blur on the left, was captured by the burst of a flash unit less than a thousandth of a second after the encounter with the match. The match, however, did not burst into flame until about a hundredth of a second after the collision. Brian measured this delay in ignition in a series of experiments in his junior and senior years at NCSSM. He is now a freshman at the University of North Carolina."Milk Modeling" -- Richard Turlington, 1994
A knowledge of physics and photography and a bit of luck were required to produce this photograph of leaping milk drops, colored with food dye. The liquid columns were produced when the platform on which the milk drops initially rested was accelerated rapidly downward. A flash unit was triggered as the platform passed through a laser detection beam. Richard took the photograph in his senior year at NCSSM. He is now studying physics and philosophy at the University of North Carolina."Needle Burst of an Underwater Air Balloon" -- S. Ross Little, 1990
This photograph was Ross' answer to the challenge of creating an original high-speed photograph. He submerged an air balloon in a tank of water and inserted a needle near the top. A sound trigger located at the water's surface detected the sound of the burst. The photograph shows the interior cavity of air that remained for a short time while the balloon itself was collapsing. Ross took this photograph in his senior year at NCSSM. He graduated from Brown University in 1994 with a degree in International Relations."Popping the Bottom Off a Glass Bottle" -- Dara Eberly and Justin Petersen, 1995
A disc of glass broke off the bottom of this bottle of tinted water as a result of the force of Justin's palm on the mouth of the bottle. The pressure in a small air space in the neck of the bottle increased greatly and was transferred to the water inside the bottle. Justin used a foam pad and a glove to protect his hands. Dara and Justin took the photograph as part of a project in the High-Speed Photography course at NCSSM."Racquetball Colliding With a Wall" -- Eric Deren and Sean McGrew, 1992
These are three in a timed sequence of images of a racquetball striking a wall. The ball was propelled toward the right at 60 mph using a giant slingshot. The ball struck a metal plate on the wall, pushing that plate into contact with a second one and thereby completing an electrical circuit to discharge the flash unit. The time given in milliseconds below each photo is the time elapsed since the ball first touched the wall. Eric and Sean took many such photos during their junior year at NCSSM in order to document the entire collision process."Shattering Daisy" -- Kelly Cooke, 1994
A daisy frozen in liquid nitrogen was shattered by the passage of a BB. The BB is seen as a fuzzy, white spot below the daisy. Kelly took this photograph in her senior year at NCSSM. She spent much of that year designing and presenting outreach programs in high-speed imaging for elementary school students. Kelly is currently a freshman at the University of North Carolina."Splash on a Glass" -- Curtis Hurley, 1996
The crown formed when a drop splashes into a shallow pool is a phenomenon familiar to most of us, thanks to the work of Harold Edgerton. Curtis' photograph is a successful exercise in imitation. The photograph is actually a double exposure. The image of the drop at the top was taken after the image of the preceding splash. Curtis is an 8th grader and has helped present programs on light and color at the Edgerton Explorit Center."Splash of a Potato" -- Andres Fernandez and Wesley Williams, 1995
A slice cut from a raw potato splattered as it struck a wall at high speed. An air gun made of PVC pipe was used under closely-controlled conditions in a laboratory to accelerate the potato slices without endangering the experimenters. The splash was captured using a photogate mounted just in front of the wall. Andres and Wesley also measured the speed of the potato pellet and found it to be 150 mph."Leap of a Popcorn Kernel" -- Joe Strunk, 1990
A popcorn kernel is seen bursting open as it pushes off a hot plate in this multiple-image photograph. The flash sequence was timed and controlled by a computer, triggered when the kernel passed through a laser beam. Joe shot nine rolls of film over a one-week period in order to obtain a few photographs like this one. One of his photographs was published on the cover of The Physics Teacher (9/91). Joe took the photograph while in his senior year at Casady School. He graduated from Oklahoma State University in 1995 with a degree in mechanical engineering."Bubble Bombing" -- Shelby Cave, 1994
A falling water drop is seen colliding with the top of a soap bubble. Both the drop and the bubble are distorted in the collision. Shelby took this photograph as part of a long-term project during her junior and senior years at NCSSM. Her original goal was to photograph soap bubbles while bursting open, but she found that the water drops passed through the bubbles without bursting them."Waveforms on a Plucked Rubber Band" -- Harindran Manoharan, 1987
Four colored images of a stretched rubber band were captured after the band was released from a clamp below the bottom of the hoop. The colors, produced by filters on four flash units, serve as markers to record the image sequence. The first, yellow, image was captured as the band passed through a photogate, and the remaining images occurred about a half cycle apart in the order blue, red, and green. Hari took the photograph at Casady School as part of an experimental study of waveforms. He is currently working on a doctorate in electrical engineering at Princeton.