Photo of physicist Robert Cornog
The Lawrence Berkeley National Laboratory has put more of their photo archive online-- or, at least, I have just discovered more of their photos.
There are a number of pictures I hadn't seen before of Heinlein's friend Robert Alden Cornog, a physicist and engineer (and beam jockey). Here's a link to the best one:
It's 8 May 1941. Cornog is standing at the construction site for the new 184-inch cyclotron and the building that will house it. He has been deeply involved with the planning and procurement for this project, which is massive by the scales of 1930s physics. At the same time, he has been experimenting with beams from the 60-inch and 37-inch cyclotrons.
The circular, domed building remains, though it's housed a series of different accelerators, and it's a distinctive landmark that symbolizes physics in Berkeley.