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A HOLOGRAM, WIKIPEDIA EXPLAINS, “is made by superimposing a second wavefront (normally called the reference beam) on the wavefront of interest, thereby generating an interference pattern which is recorded on a physical medium.”
It’s a heady description for what we recognize as a planar image seemingly viewable in three dimensions by subtle shifting of viewpoint.
Holography History. Wikipedia says, “The development of the laser enabled the first practical optical holograms that recorded 3D objects to be made in 1962 by Yuri Denisyuk in the Soviet Union and by Emmett Leith and Juris Upatnieks at the University of Michigan, USA.”
Wikipedia notes, “The Hungarian–British physicist Dennis Gabor (in Hungarian: Gábor Dénes) was awarded the Nobel Prize in Physics in 1971 ‘for his invention and development of the holographic method.’ ”
Indeed, Wikipedia lists nine different applications of holography, including high security registration plates, interferometric microscopy, data storage, and art.
Holography and the Narrative. Janet Murray’s Hamlet on the Holodeck: The Future of Narrative in Cyberdeck is a classic work about digital storytelling. I recall reading it back in 1997 as something of sci-fi literature.
Professor Murray combined her talents in humanities and technology at MIT’s Center for Education Computing Initiatives and, since 1999, at Georgia Tech’s School of Literature, Media and Communications. One of her projects was designing a digital edition of the Warner Brothers classic Casablanca.
Control-line Aircraft. The sole hologram in my collection is an image of what appears to be a model airplane engine. As a kid, I was into control-line aircraft, models that flew at the end of 60-ft wires, under control of one revolving with their flight.
In retrospect, how I avoided dizziness from spinning around still puzzles me. It was quite the hobby, for example, with highly detailed scale-model sport flying as well as combat and aircraft carrier activities.
Combat planes, flying the same circle, have paper streamers fixed to their tails. The game is to snip off the other’s streamer without tripping over each other or entangling control lines. Good, chaotic fun.
Carrier event requires a scale model of an actual carrier aircraft. The plane takes off from the carrier deck, curved to accommodate the 60-ft control wires. It first does hot laps, then, with suitable engine control, slow laps, followed by a flyer-dictated return to the carrier deck, the plane’s tail hook engaging one of the deck’s three arresting cables.
Indeed, I swapped this hobby for sports cars once I reached driving age. The hobby, also known as U-control, continues to thrive.
Power. Model airplanes of my experience were typically powered by single-cylinder two-stroke engines, displacements from 0.049 to 0.60 cu. in. “Nineteens” (0.19 cu. in.) and “thirty-fives” (0.35 cu. in.) were common choices, with two companies, K&B and Fox, both still in business, having their adherents (I was a K&B guy).
My Four-Stroke Hologram. Most model airplane engines are two-strokes, with internal port valving rather than intake and exhaust valve actuation. By contrast, this hologram shows pushrods and overhead valves.
This particular hologram rewards lateral rather than vertical views, so it’s difficult to see the overhead rocker arms. What’s more, photographing a hologram can be quite a challenge.
A professional approach employs some sort of stabilization for the hologram’s angle and a tripod for the camera. Indeed, best results involve a single light source in a darkened room, the camera and shooter draped behind a pin-holed black cloth.
Please excuse my modest happy snaps. ds
© Dennis Simanaitis, SimanaitisSays.com, 2021