Solar Synchronizer
June 4th, 02007 by Alexander Rose 
Long Now recently completed this prototype of the Solar Synchronizer for the 10,000 Year Clock, and it is now on display at our San Francisco Museum & Store. This mechanism will help the Clock keep accurate time over the millennia. While the Clock’s day to day time-keeper is a slow pendulum, a mechanism like this one is needed to correct drift over the long haul. On any sunny day, when the sun lines up with this mechanism, light is focused onto a piece of nickel-titanium wire that reacts when heated by the sun. This motion is used to synchronize the Clock to solar noon. The synchronization is also modified slightly by the equation of time cam, which accounts for the +/- 15 minute difference of solar to absolute time. Due to meteor impacts and volcanic eruptions, the clock may not see the sun for several years, so it must be accurate enough to stay within the range of this correction during those times.
This mechanism was originally conceptualized by Danny Hillis, project management and additional design by Alexander Rose, lead engineers were Paolo Salvagione and Greg Staples, and lead machinist and fabricator was Christopher Rand. Shape memory alloy calculations and consulting by Pete Von Behrens of Alternative Motion Solutions.
All engineering for the Clock of the Long Now is done in Pro Engnineer courtesy of PTC. All CAM processing is done in GibbsCAM courtesy of Gibbs & Associates. The Long Now Foundation thanks them for their support.
June 4th, 2007 at 6:33 pm
zowie!
so exciting to see this.
June 4th, 2007 at 8:07 pm
wow, this is great! If the ambient temperature is very cold will the nickel-titanium wire still have the desired calibrating effect?
June 8th, 2007 at 1:59 pm
This is so cool! I can not wait to see it in-person.
June 11th, 2007 at 7:17 am
“wow, this is great! If the ambient temperature is very cold will the nickel-titanium wire still have the desired calibrating effect?”
Good question. The wire does have some absolute temperature limits (though you could replace it with new wires in the future that are made for a the ambient normal) In the final install underground however, the wire will be inside, sealed from the elements by the lens, and its temperature sinked to the surrounding rock. This should minimize the need to replace the wire in the future.
July 6th, 2007 at 11:10 am
Interesting design. I’m curious about how clean/clear the outer lens needs to be in order for this to work. In the event of massive amounts of debris in the atmosphere, what is the likelihood that something like this would function after some of it settled directly on this device?
July 26th, 2007 at 11:38 am
Demetirus Nelon’s point brings to mind the new (and not yet well-established) technology of a transparent coating of titanium dioxide on the outer surface to catalytically oxidize at least the organic contaminents.
September 11th, 2007 at 12:05 pm
How about a coating of a material which has some kind of lotus effect? Like that, rain can wash the lense clear again after it has been soiled with mud… rain at least is supposed to fall every once in a while, isn’t it?
March 6th, 2008 at 5:31 pm
[…] Through a fairly low power laser process some clever folks over at the University of Rochester have come up with a way to generate an intrinsic colored surface on metals. They can even get an extremely pure black. Why is this cool? For the Clock of the Long Now project we are always on the lookout for ways of coloring metal for parts of the clock in ways that wont fail over time. A process like this could be used on the dials, or even on metals that we need to absorb sunlight to give us temperature variation. […]