Solar Synchronizer

Posted on Monday, June 4th, 02007 by Alexander Rose - Twitter: @zander
link Categories: Clock of the Long Now   chat 0 Comments

http://web.longnow.org/share/longnow/pressPDF/blog-img/solar-synch.jpg

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.

http://web.longnow.org/share/longnow/pressPDF/blog-img/trigger-draw.gif

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.

  • http://www.flickr.com/photos/campen bryan

    zowie!
    so exciting to see this.

  • http://www.jsclarkstudios.com Jesse Clark

    wow, this is great! If the ambient temperature is very cold will the nickel-titanium wire still have the desired calibrating effect?

  • http://www.glassparadigm.com Heather Durham

    This is so cool! I can not wait to see it in-person.

  • http://www.longnow.org Alexander Rose

    “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.

  • Demitrius Nelon

    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?

  • Mark

    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.

  • Joey

    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?

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  • http://aksebazigar.anzaliblog.com/ عکس بازیگران

    thank you (usefull)

  • http://--none-- Tom Burnham

    What about the changing number of days per year??? Chapront (1997) gives a formula which implies that days will be almost a minute longer in Y12K than they are today and that the cumulated difference will be about three days. The latter would presumably appear as errors in your astronomical outputs.

  • http://--none-- Tom Burnham

    Use of “shape memory alloy” appears to be yet another violation of your supposed guiding principle of maintainability by bronze-age technology.

  • http://www.longnow.org Alexander Rose

    “Tom Burnham was all:

    What about the changing number of days per year??? Chapront (1997) gives a formula which implies that days will be almost a minute longer in Y12K than they are today and that the cumulated difference will be about three days. The latter would presumably appear as errors in your astronomical outputs.”

    The only part of the Clock that cares about absolute noon is the pendulum that is corrected through the Equation of Time cam by the solar trigger. That cam is 3 dimensionally curved to compensate for the slowing of the earths rotation, plus the precessional cycle.

  • http://www.longnow.org Alexander Rose

    “Tom Burnham was all:

    Use of “shape memory alloy” appears to be yet another violation of your supposed guiding principle of maintainability by bronze-age technology.”

    Yes this is the part I like the least about this solution. We can store a lot of the material with the clock as one solution. Or can use a large lever made from two materials that expand at different rates, but there are few materials that expand a lot with temperature and are long lasting. And even so it makes it less accurate than the SMA solution.

  • Scott Boek

    YAAAWWWWWNNNNN…………………………

    Yet another FANTASTIC waste of funds.
    Clap-clap!

    After all …isn’t the world “as we know it” ending in ’2012′. Think my SWATCH will do just FINE ;)

  • Wm Jon Ackley

    Such things as this beatiful notion of allowing engineering to mate with high art, helps us understand, and reach out to touch the Cosmos that The Universal Architect set in motion. Bravo…… This when complete will be the eighth wonder of the world, in half a million years it is something I would feel proud to have found by an alien xenoarchiologist…..

  • Scott M

    I can’t think of many glass-like materials that won’t flow and deform over time; I don’t think that lens is going to stay accurate for too many centuries, if, as it appears, it’s only supported at the edges.

    And if the idea is to build the clock out of materials that don’t tempt thieves… that lens looks like a pretty tempting target. Would you be better off with a mirror hollowed out of a block of metal too bulky to easily walk off with?

  • John Edds

    Scott M., that’s actually an oft repeated myth. Glass does not flow over time. If it did, the optics in telescopes and reading glasses that are centuries old would be off–they are not. Glass-wares created in ancient times would have slumped into puddles–they have not. Obsidian (natural glass) arrow and spear points wouldn’t remain recognizable, let alone retain their sub-micrometer edges.

  • Angus M

    Look through any window from say, the Georgian era, you will find the view is distorted as a result of the tiny summer melt within the glass produced every year.

  • Duane Watson

    I wish you had started a hundred years ago. I would love to visit the final installation. I guess the journey is the real point.

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  • Roger Ush

    I guess the real thing to consider is the lifespan of a culture that supports the maintenance or the non-destruction of such a device.

    I can't think of a singular culture that has gone more than a couple hundred years without destruction and violent upheaval let alone one that would last tens of thousands of years while maintaining the health of a singular object.

    I guess that's why the oldest living monuments are non-mechanical monoliths, all of which even though the physical object remains, the idea behind it has long since been lost.

  • http://profiles.google.com/albertson.chris Chris Albertson

    One glass-like material that does not flow over time is “glass”.   The idea that some how it flows is a myth.  People do see old windows with non-uniform thickness but they were like that when new.    

  • Arlen Lott

    I am wondering what effect that the theoretical shifts in the Earth’s magnetic poles might have on the functioning of this magnificent timepiece?

  • John Olomon-Howell

    Well, technically speaking, glass does sag ever so minutely. In fact, the most recent paper I read on the subject notes that such changes might even become visible to the naked eye in as little as 10³² years or so.


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