The 10,000 Year Clock

Introduction
• Background
• Principles
• Prototype 1
• Orrery
• Chimes
• Nevada
• Other Ideas

These are the principles that Danny Hillis used in the initial stages of designing a 10,000 Year Clock. We have found these are generally good principles for designing anything to last a long time.

Longevity

With occasional maintenance, the clock should reasonably be expected to display the correct time for the next 10,000 years.

Maintainability

The clock should be maintainable with bronze-age technology.

Transparency

It should be possible to determine operational principles of the clock by close inspection.

Evolvability

It should be possible to improve the clock with time.

Scalability

It should be possible to build working models of the clock from table-top to monumental size using the same design.

Longevity:: Go slow; Avoid sliding friction (gears); Avoid ticking; Stay clean; Stay dry; Expect bad weather; Expect earthquakes; Expect non-malicious human interaction; Dont tempt thieves
Maintainability and transparency:: Use familiar materials; Allow inspection; Rehearse motions; Make it easy to build spare parts; Expect restarts; Include the manual
Scalability and Evolvabilty:: Make all parts similar size; Separate functions; Provide simple interfaces

Examples:

	Clepsydra (water clock)	Atomic Clock
Power	potential energy supplied by human	electricity
Time	flow rate of water	oscillation of cesium atom
Convert	lever with e.o.t. adjustment	electronic frequency divider
Display	pointer, gong	numeric display, radio

Options considered for powering the Clock:

Atomic	Poor maintainability&transparency
Chemical	Poor scalability
Solar Electric	Poor maintainability
Pre-stored potential energy	Poor scalability
Water flow	Exposure to water
Wind	Exposure to weather
Geothermal	Poor scalability
Tidal gravitational changes	Poor scalability
Temperature change	...
Pressure change	Need for bellows or seal
Seismic and plate tectonic	Poor scalability
Human winding	Fosters responsibility

Conclusion: My current favorite is human winding because it fits with goals of clock. Temperature change is also a viable alternative.

Options considered as sources of timing for clock:

pendulum	inaccurate
spring and mass	inaccurate
water flow	inaccurate and wet
solid material flow	inaccurate
daily temperature cycle	unreliable
seasonal temperature cycle	imprecise
tidal forces	difficult to measure
earths rotating inertial frame	difficult to measure accurately
stellar alignment	unreliable (clouds)
solar alignment	unreliable (clouds)
atomic oscillator	too high tech, difficult to maintain
piezoelectric oscillator	too high tech, difficult to maintain
atomic decay	difficult to measure precisely
wear and corrosion	very inaccurate
marble roll	very inaccurate
diffusion	inaccurate
tectonic motion	difficult to predict and measure
orbital dynamics	difficult to scale
audio oscillator	inaccurate and difficult to measure
pressure chamber cycle	inaccurate
inertial governor	inaccurate
human ritual	too much dependence on humans

Conclusion: Since no single source does the job, use an unreliable timer to adjust an inaccurate timer, creating a phase locked loop. My current favorite combination is to use solar alignment to adjust a slow mechanical oscillator.

Options considered for the part of the Clock that
converts time source to display units:

Electronics	Poor maintainability&transparency
Gears	Need for rational approximation
Pre computed display	Lots of calendar pages
Levers	Require very slow timing source
Hydraulics	High power
Mechanical Digital Logic	...

Conclusion: Mechanical digital logic.

Options for how to display time:

chimes	Poor maintainability&transparency
flutes or whistles	cannot sound too often
sweeping hand	fragile, confusing for many hands
concentric rotating rings	...
balls in holes	creates collectibles
shadows, beams of light	...
animation	high power

Conclusion: This is the one I have thought about the least. Note that there can be multiple displays, and that some display can have independent power sources.

Some options for what to display:

Display	Days per cycle
Time of Day	1
Phase of moon	29.5305882
Lunar eclipses	-6793.504897308
Season	365.242
Positions of visible planets	mercury 87.969 venus 224.701 earth 365.256 mars 686.980 jupiter 4331.772 saturn 10759.22
Procession of zodiac	9417404.8533435
Christian Calendar	approximates solar years
Moslem Calendar	approximates lunar years
Jewish calendar	...
Chinese calendar	...
Mayan calendar	360
day count	1
moon count	29.5305882
year count (centuries, millennia)	365.242
historical events (past and future)	...

Other information to display: (library functions)

future time scales	...
astronomical ephemeris	...
maintenance manual	...
visits to the clock	...
weather records	...
earthquake records	...
calendar systems	...
general useful knowledge	...

The design principles for the clock were primarily the work of Daniel Hillis with additional thoughts brought about by discussion with the other founding board members.

The 10,000 Year Clock

Longevity

Maintainability

Transparency

Evolvability

Scalability

Examples:

Options considered for powering the Clock:

Conclusion: My current favorite is human winding because it fits with goals of clock. Temperature change is also a viable alternative.

Options considered as sources of timing for clock:

Conclusion: Since no single source does the job, use an unreliable timer to adjust an inaccurate timer, creating a phase locked loop. My current favorite combination is to use solar alignment to adjust a slow mechanical oscillator.

Options considered for the part of the Clock that
converts time source to display units:

Conclusion: Mechanical digital logic.

Options for how to display time:

Conclusion: This is the one I have thought about the least. Note that there can be multiple displays, and that some display can have independent power sources.

Some options for what to display:

Other information to display: (library functions)

Next Seminar

Previous Seminars

Latest Blog Posts

About Long Now

The 10,000 Year Clock

Longevity

Maintainability

Transparency

Evolvability

Scalability

Examples:

Options considered for powering the Clock:

Conclusion: My current favorite is human winding because it fits with goals of clock. Temperature change is also a viable alternative.

Options considered as sources of timing for clock:

Conclusion: Since no single source does the job, use an unreliable timer to adjust an inaccurate timer, creating a phase locked loop. My current favorite combination is to use solar alignment to adjust a slow mechanical oscillator.

Options considered for the part of the Clock that converts time source to display units:

Conclusion: Mechanical digital logic.

Options for how to display time:

Conclusion: This is the one I have thought about the least. Note that there can be multiple displays, and that some display can have independent power sources.

Some options for what to display:

Other information to display: (library functions)

Next Seminar

Previous Seminars

Latest Blog Posts

About Long Now

Options considered for the part of the Clock that
converts time source to display units: