Building ED-1
The first EarthDial is designed with materials that I hope are available almost anywhere in the world. It’s the EarthDial you see at http://planetary.org/mars/earthdial.
I wanted ED-1 to be accessible and as far from shadows as I could manage. Convincing my neighbors to tear down their houses for the sake of good sun seemed beyond the scope of this project, so I hung the dial over the edge of a railing.
Plywood and paper are readily available. Wood grains are elegant, and they evoke the materials that our ancestors may have used to create the first sundials our species ever built.
For the gnomon post, I went with stainless steel. Threaded metal rod is tough. Stainless steel is impervious to most weather, and it’s strong enough to support the whole dial, should it be used for a carrying handle (on purpose or by accident).
To represent the Pacific Northwest, I used paper images held down with decoupage glue and then heavily varnished. I may come up with another version of the Space Needle soon. I won’t turn the camera off, though, while I’m working on it.
The biggest challenge for most EarthDialers is setting up the camera. In the Northern Hemisphere, it’s great to hang your camera on a long arm from the north, because you get no camera shadows on the dial face. I put my camera in the floatable yellow flashlight you may have seen on the home page. After a month or so, it leaked a little bit. I sealed it back up just by greasing the threads with petroleum jelly (Vaseline®-style grease). The grease itself is nearly waterproof, and the now-lubricated flashlight collar screws down tighter making a better seal.
The farther a little web cam gets from its host computer, the more trouble it can be. But for almost all of us, the signal has to go from the camera to a building. Wireless cameras are beyond the reach of most of us. And, the batteries for these units can run down very quickly. So, I came up with a series of Universal Serial Bus (USB) hubs, which I have enclosed in weather-tight boxes.
Each has to have its own extension cord and its own mounting so that it can have sufficient room for “drip loops,” to keep water out. One small advantage to using hubs and runs of electrical cords is that it keeps these junction boxes warm. That helps drive moisture away from your connections. It might seem like a lot of trouble, but in Seattle in the winter, it’s rain, rain, rain. So far it has worked very well. We’ll see as the weather warms and every part of the system goes through more hours.
Good luck my fellow EarthDialers. Let’s help people everywhere understand our place in the Cosmos with our sundials here and on Mars. Let’s change the world.
