The Geochron World Time Indicator is a clock that doubles as a live map of where the sun is shining on the Earth. Back in its day, it was a cult piece that some have dubbed the “Rolex on the wall.” Wired’s recent coverage of the clock reminded us of just how cool it is on the inside. And to dig in, we like [Attoparsec]’s restoration project on his own mid-1980s Geochron, lovingly fixing up a clock he picked up online.
[Attoparsec]’s recent restoration shares insights into the clock’s fascinating mechanics. Using a synchronous motor, transparent slides, and a lighted platen, the Geochron works like a glorified slide projector, displaying the analemma—a figure-eight pattern that tracks the sun’s position over the year.
But if you’re looking for a digital version, way back in 2011 we showcased [Justin]’s LED hack of FlorinC’s “Wise Clock”, which ingeniously emulated the Geochron’s day-night pattern using RGB LEDs, swapping out the faceplate for a world map printed on vellum. That’s probably a much more reasonable way to go these days. Why haven’t we seen more remakes of these?
Who is going to be the first to say “use a 555”?
With the price of large displays getting low and lower – why not use a color display and do the math and such with something like a RPi? And add a display in the corner for local time and the moon?
Geochron makes an electronic version that uses a monitor or TV. There’s also HamClock which does something similar with a Raspberry Pi.
Some people just like the mechanical version just like some people like mechanical watches.
For Windows there’s Simon’s World Map Clock, which is very versatile.
There are several Geochron apps in the Android store (as well as a Flat Earth Geochron app for the F.E.’s)
As long as it uses the warped and wrong Mercator projection instead of the equal angle and correct sized Waterman butterfly projection I have to hiss as Earth scientist and walk backwards in my den.
The Mercator has the advantage of filling a rectangular area, but I also don’t like it.
In truth all map projections have flaws and downsides, it’s a globe or nothing IMHO.
A spherical display geochron that rotated would be super cherry, if anyone knows of a display that could pull that off please link it :)
It’d be as simple as a globe with a half-light from the inside, no? The only reason the geochron looks so weird is that the light pattern has to be distorted just as stupidly as the projection. Warp it back into 3D and it’s just a hemisphere again.
This is an existing product, Geomart has it sold as the Marco Polo Illuminated Desktop Globe. It’s sold out right now but it looks like it normally fetches $400-500, so way cheaper than a Geochron, and arguably better.
This should be 3d-printable as a lithophane…
Proof the world is really flat ;)
Someone needs to make a Disc-World-Chron (Color Of Magic/Terry Pratchet) or a Ring-World-Chron (Larry Niven) or even a Dyson-Chron. Just a thought… probably already done.
(Addendum)….I was referring to a physical/mechanical type of clocks….use of 555’s optional (captnmike)