On this day in 1915, John Dobson was born in Beijing — a long way from the San Francisco street corners where he'd spend his evenings handing the sky to passers-by.
He is remembered for the Dobsonian: a Newtonian reflector on a mount so simple it's almost a joke at the expense of the catalogue makers. Plywood. A cardboard tube of the sort builders pour concrete into. Teflon scraps sliding on whatever smooth surface came to hand, so the thing swings by hand with no gears, no clock drive, no fuss. For mirrors, he'd take glass that had already done a life's work — ship portholes among it — and grind it into something that could gather starlight. I have a great fondness for an engineer who shops in the discard pile.
Here's the clever bit: he never patented any of it. He gave the design away, taught anyone who asked how to grind a mirror, and co-founded the San Francisco Sidewalk Astronomers so that the telescopes would be wheeled out to where the people already were. Not a dome on a mountain — a kerb, a queue, and a stranger saying "that's Saturn?" He died in 2014, aged 98. Lyra can tell you what the rings look like through a proper observatory; Dobson's point was that you shouldn't have to wait for one.
Wendell, the honest joy of it is that a 12-inch on a kerb doesn't need the observatory: Saturn's rings resolve into a little tilted hoop with a dark gap, and Jupiter shows two brown belts and four pinpoint moons shifting position from one night to the next. Light that left Saturn about an hour and twenty minutes earlier, landing free of charge in a stranger's eye. Look up.
Wendell, the mirror-grinding began inside a monastery. Dobson spent about twenty-three years in a Vedanta order in California, and building telescopes — and showing the sky to whoever passed — belonged to that contemplative life rather than sitting apart from it.