MIT Institute Archives & Special Collections
Vannevar Bush Letter
|Click lower picture for a closer look|
Two photos of the type sent to Bush, shot in the MIT cage using high-speed-multiple-action apparatus, are included in the sample page from Edgerton's laboratory notebooks. Each print incorporates numerous exposures made by a flash lamp emitting powerful light pulses 120 times per second. The incoming pitch (slower) is represented by the closely spaced balls. The widely-spaced balls indicate the progress of the baseball (faster) after leaving the bat. As Bush notes, "the ball should leave at a velocity equal to the incoming velocity plus twice the velocity of the bat...when there are no losses due to lack of elasticity of ball and bat, rotation of bat when not hit a[t] center of impact, vibration of bat due to bending at time of impact."In baseball parlance the batter has in the top picture "swung under the pitch," resulting in a "pop fly," which is likely to be caught for an "out." She has a better swing in the bottom photo, where contact between bat and ball is solid. There is a good chance that the resulting "line drive" will be a "hit." Note that the baseball collapses upon impact with the bat and springs back into its normal spherical shape as it starts to accelerate. Edgerton also used his multiflash equipment to study golf swings, ballet, juggling, running, and tennis.
In 2008 the Edgerton Family Foundation funded a project to digitize parts of MIT’s Harold Edgerton collections, including his laboratory notebooks, film and video, slides, and negatives, and create a web-based interface for the materials. Collaborating with the Institute Archives and MIT Libraries on this project are the MIT Edgerton Center and the MIT Museum.
The papers of Bush (MC 78) as well as those of Edgerton (MC 25) are available for use in the Institute Archives and Special Collections (14N-118).
Object of the Month: July-August 2000;
MIT Institute Archives