Engineer and photographer Harold Edgerton was born #OTD in 1903.
Edgerton pioneered various forms of high-speed photography using specialized cameras, strobe lighting, and other techniques. You’ve probably seen many of the images he created!
Images: MIT; H. Edgerton
While working at EG&G, Edgerton and his colleagues developed the “Rapatronic” camera. Its shutter had no moving parts and could capture exposures as short as 2 microseconds.
This new camera allowed for high speed photos of atomic bomb tests. Notice the silhouettes of the Joshua trees in this photo.
What’s going on in these photos?
The roughly spherical blob is the shockwave from the blast, and the white splotches are bits of bomb casing catching up with it.
What about the protrusions emerging from the sides and bottom of the blast?
Images: Public Domain
In these tests, the bomb sat at the top of a support tower and was held in place by steel mooring cables. (You can see the tower if you zoom in.)
Those glowing protrusions are the cables vaporizing. This phenomenon is known as the “rope trick effect.”
Image: Public Domain
Here is a gif of the rope trick effect from a video recorded with Edgerton's Rapatronic camera.
The vaporization races down the cables, outpacing the shockwave from the blast. At the end you can also see bits of bomb casing catching up with the blast.
You can see loads more Edgerton photos (including some cool images produced with the Schlieren Method) here:
http://edgerton-digital-collections.org/galleries/iconic
Images: H. Edgerton, MIT
@mcnees Love that "nude descending a staircase" effect in the diver photo.
Amazing creativity capturing that data.
@mcnees I always wonder whether these exposures can be calibrated retroactively, i.e. whether there is enough data to get approximated luminance values for every pixel, so one could have a comparison, e.g. looking at the sun vs. that
they look just so unreal
@mcnees
It was late in the day, and as I walked past, he was standing with his hands clasped behind his back, reading the bulletin board with job opportunities. Being the grad-student smartass that I was, I piped up and said "Looking for a career change Doc?" He smiled at me and replied "It's never too late, you know!"
He passed away a couple of weeks after that. I prefer to think of it as a career change. 2/
@mcnees
Harold “Doc” Edgerton, MIT professor of electrical engineering:
Doc, also known as Papa Flash, transformed the stroboscope into a tool for sonar and deep-sea photography.
Jacques Cousteau used his equipment in shipwreck and Loch Ness monster searches.
Like many MIT faculty, Doc was a student there, getting an advanced degree in 1931 and never left.
His high-speed photography also became a new art form and his short film on stroboscopic photography won an Oscar in 1940.
https://aotus.blogs.archives.gov/2019/12/20/remembering-doc-edgerton/
One of the great things about growing up the libraries of the Massachusetts Institute of Technology was getting to work with retired faculty. No one ever seemed to really retire at MIT! Most retain…
I got to meet him when I toured MIT!
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