Photo is from my dimly lit "lab" and shows the result of a narrow 635nm laser beam being shattered by a pair of 40 micron slits spaced about 12 microns apart. The device the diffracted beam is falling on is an optical sensor mounted on a high-resolution positional encoder.
Like very many people, I have been spending too much time ensconced in the news of our nation and balancing on the precipice of despair. No one can look over that edge indefinitely without tumbling in, and for me, it's time to look away for just a little while.
When I still lived with my kids, we had converted the garage into a first rate lab. Now that I'm living at my "mountain hold" in the woods again, I have only a small fraction of the "lab space". What (barely) passes for a lab now is a single two meter long bench, jammed with microscopes, an optical rail, a computer workstation and too much lab gear... all of which make the bench too crowded to do anything useful.
I spent some time tonight clearing the bench of anything that wasn't absolutely necessary and moving microscopes and the workstation to the side and as far out of the way as I could. The end goal was restoring the optical rail and sensors to full functionality so I could spend a few days doing experiments that would allow me to think deeply about diffraction, interference, and the weird nature of light.
If one passes the photons of a coherent beam of light through a very, very thin slit (or a pair of them), the light shatters and crashes upon itself like ocean waves. In the dark and light patterns made by those crashing waves lie secrets of what a mysterious and unexpected wonder light is. If one has the right equipment, one can measure those waves, capture them as a stream of data, and analyze them at leisure.
And that is how I find myself awake at 2am in a room entirely dark but for the light of a 635nm laser and the glow of a computer monitor, thinking about Huygens and Newton and Young and nature of light while Jethro Tull fills the house with comforting music from a half-century ago.
In the time spent staring at squiggly graphs on a screen and scrawled equations on a notepad, I am once again thrilled at the wonder of the universe, and grateful that nature will show her secrets to all that have the eyes to see and the patience to ask questions persistently. "Why?" is the most glorious question in the English language.