 The first prototype, on display at the Science Museum in London. - "I want to build a clock that ticks once a year. The century hand advances once every one hundred years, and the cuckoo comes out on the millennium. I want the cuckoo to come out every millennium for the next 10,000 years. If I hurry I should finish the clock in time to see the cuckoo come out for the first time."
- — Danny Hillis
The Clock of the Long Now, also called the 10,000-year clock, is a proposed mechanical clock designed to keep time for 10,000 years. The project to build it is part of the Long Now Foundation. Image File history File linksMetadata Download high resolution version (1524x2032, 537 KB) Summary The Clock of the Long Now, taken by Phillip Kirlin, in September 2005. ...
Image File history File linksMetadata Download high resolution version (1524x2032, 537 KB) Summary The Clock of the Long Now, taken by Phillip Kirlin, in September 2005. ...
To meet Wikipedias quality standards, this article or section may require cleanup. ...
An analog wall clock A clock (from the Latin cloca, bell) is an instrument for measuring time and for measuring time intervals of less than a day—as opposed to a calendar. ...
The Long Now Foundation, established in 1996 (or 01996), is a private organization that seeks to become the seed of a very long-term cultural institution. ...
The project was conceived by Danny Hillis in 1986 and the first prototype of the clock began working on December 31, 1999, just in time to display the transition to the year 2000. At midnight on New Year's Eve, the date indicator changed from 01999 to 02000, and the chime struck twice, to ring in the "third millennium". That prototype, approximately two meters tall, is currently on display at the Science Museum in London. To meet Wikipedias quality standards, this article or section may require cleanup. ...
1986 (MCMLXXXVI) was a common year starting on Wednesday of the Gregorian calendar. ...
December 31 is the 365th day of the year (366th in leap years) in the Gregorian Calendar. ...
1999 (MCMXCIX) was a common year starting on Friday, and was designated the International Year of Older Persons by the United Nations. ...
This article is about the year 2000. ...
For the musical instrument, see tubular bell. ...
The third millennium is the third period of one thousand years in the Common Era. ...
The National Science Museum in London The Science Museum on Exhibition Road, Kensington, London, is part of the National Museum of Science and Industry. ...
London (pronounced ) is the capital city of England and of the United Kingdom. ...
Design The basic design principles and requirements for the clock are: - Longevity: The clock should be accurate even after 10,000 years, and must not contain valuable parts (such as jewels, expensive metals, or special alloys) that might be looted.
- Maintainability: Future generations should be able to keep the clock working, if necessary, with nothing more advanced than Bronze Age tools and materials.
- Transparency: The clock should be understandable without stopping or disassembling it; no functionality should be opaque.
- Evolvability: It should be possible to improve the clock over time.
- Scalability: To ensure that the final, large, clock will work properly, smaller prototypes must be built and tested.
Obviously, no clock can have a guaranteed lifetime of 10,000 years, but some clocks are designed with guaranteed limits. (For example, a clock that shows a four-digit year date will not display the correct year after the year 9999.) With continued care and maintenance the Clock of the Long Now could reasonably be expected to display the correct time for 10,000 years. A selection of gemstone pebbles made by tumbling rough rock with abrasive grit, in a rotating drum. ...
The Bronze Age is a period in a civilizations development when the most advanced metalworking has developed the techniques of smelting copper from natural outcroppings and alloys it to cast bronze. ...
Whether a clock would actually receive continued care and maintenance for such a long time is debatable. Hillis chose the 10,000-year goal to be just within the limits of plausibility. There are technological artifacts, such as fragments of pots and baskets, from 10,000 years in the past, so there is some precedent for human artifacts surviving this long, although very few human artifacts have been continuously tended for more than a few centuries.
Power considerations Many options were considered for the power source of the clock, but most were rejected due to their inability to meet the requirements. For example, atomic energy and solar power systems would violate the principles of transparency and longevity. In the end Hillis decided to require regular human winding of a falling weight design. This may seem an odd choice, but the clock design already assumes regular human maintenance. Atomic energy is an outdated phrase which can mean a number of things related to energy produced by atoms: In the late- 19th century through the early- 20th century, it was often used to describe the particles ejected by radioactive elements (especially radium). ...
Solar power describes a number of methods of harnessing energy from the light of the sun. ...
Timing considerations The timing mechanism for such a long lasting clock needs to be reliable and robust as well as accurate. The options considered but rejected as sources of timing for the clock included:
Self-contained clocks Most of these methods are inaccurate (the clock will slowly become less correct) but reliable (the clock will not suddenly stop working). Others are accurate but opaque. A substance or object that is opaque is neither transparent nor translucent. ...
For other uses, see Pendulum (disambiguation). ...
In materials science, wear is the erosion of material from a solid surface by the action of another solid. ...
A torsion spring or torsion pendulum is an elastic material that reacts against torsion (twisting motion). ...
Red arrows indicate the balance wheel on this movement. ...
A water clock or clepsydra is a device for measuring time by letting water regularly flow out of a container usually by a tiny aperture. ...
The pitch drop experiment at the University of Queensland. ...
Rust, the most familiar example of corrosion. ...
This article or section does not cite its references or sources. ...
A tuning fork is a simple metal two-pronged fork with the tines formed from a U-shaped bar of elastic material (usually steel). ...
A pressure vessel is a structure designed to contain a fluid at a different pressure to the pressure surrounding the structure without changing volume. ...
A governor is a device used to measure and regulate the speed of a machine, such as an engine. ...
Atomic clock Chip-Scale Atomic Clock Unveiled by NIST An atomic clock is a type of clock that uses an atomic resonance frequency standard as its counter. ...
A crystal oscillator (sometimes abbreviated to XTAL on schematic diagrams) is an electronic circuit that uses the mechanical resonance of a physical crystal of piezoelectric material along with an amplifier and feedback to create an electrical signal with a very precise frequency. ...
Radioactive decay is the set of various processes by which unstable atomic nuclei (nuclides) emit subatomic particles (radiation). ...
External events that the clock could track or be adjusted by Many of these methods are accurate (some external cycles are very uniform over huge stretches of time) but unreliable (the clock could stop working completely if it failed to track the external event properly). Others have separate difficulties. - daily temperature cycle (unreliable)
- seasonal temperature cycle (imprecise)
- tidal forces (difficult to measure)
- Earth's rotating inertial frame (difficult to measure accurately)
- stellar alignment (unreliable because of weather)
- solar alignment (unreliable because of weather)
- tectonic motion (difficult to predict and measure)
- orbital dynamics (difficult to scale)
- human ritual (too dependent on humans).
Hillis concluded that no single source of timing could meet the requirements. As a compromise the clock will use an unreliable but accurate timer to adjust an inaccurate but reliable timer, creating a phase-locked loop. Comet Shoemaker-Levy 9 after breaking up under the influence of Jupiters tidal forces. ...
An inertial frame is a coordinate system in which Newtons First Law of Motion is valid. ...
The concept of continental drift was first proposed by Alfred Wegener. ...
Two bodies with a slight difference in mass orbiting around a common barycenter. ...
In electronics, a phase-locked loop (PLL) is a closed-loop feedback control system that maintains a generated signal in a fixed phase relationship to a reference signal. ...
In the current design, a slow mechanical oscillator, based on a torsional pendulum, keeps time inaccurately, but reliably. At noon the light from the sun, a timer that is accurate but (due to weather) unreliable, is concentrated on a segment of metal through a lens. The metal buckles and the buckling force resets the clock to noon. The combination can, in principle, provide both reliability and long-term accuracy. Weather is an all-encompassing term used to describe all of the many and varied phenomena that can occur in the atmosphere of a planet. ...
A lens. ...
Displaying the time and date Many of the usual units displayed on clocks, such as hours and calendar dates, are likely to have little meaning after 10,000 years. However, every human culture counts days, months (in some form), and years. There are also longer natural cycles, such the 26,000-year precession of Earth's axis. On the other hand, the clock is a product of our time, and it seems appropriate to pay some homage to our current arbitrary systems of time measurement. In the end, it seemed best to display both the natural cycles and the some of the current cultural cycles. The hour (symbol: h) is a unit of time. ...
A calendar is a system for naming periods of time, typically days. ...
Water, Rabbit, and Deer: three of the 20 day symbols in the Aztec calendar, from the Aztec Sun Stone. ...
The month is a unit of time, used with calendars, which is approximately as long as some natural period related to the motion of the Moon. ...
A year is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ...
Precession refers to a change in the direction of the axis of a rotating object. ...
The center of the clock will show a star field, indicating both the sidereal day, and the 26,000-year precession of the zodiac. Around this will be a display showing the position of the Sun and the Moon in the sky, as well and the phase and angle of the Moon. Outside this will be the ephemeral dial, showing the year according to our current Gregorian calendar system. This will be a five-digit display, indicating the current year as in a format like "02000" instead of the more usual "2000" (to avoid a Y10K problem). Hillis and Brand plan, if they can, to add a mechanism whereby the power source generates only enough energy to keep track of time; if a visitor wanted to see the time displayed, they would have to manually supply some energy themselves. Indo-European Zodiac signs, 16th century , medieval woodcuts The term zodiac (from Greek zodiakos [kyklos], circle of little animals, from zodiaion, the diminutive of zoon animal) denotes several places where a circle of twelve animals occurs. ...
In astronomy, a phase of the Moon is any of the aspects or appearances presented by the Moon as seen from Earth, determined by the portion of the Moon that is visibly illuminated by the Sun. ...
This article or section does not cite its references or sources. ...
The year 10,000 problem is the collective name for all potential software bugs that may emerge as the need to express years with five digits arises. ...
Time calculations Options considered for the part of the clock that converts time source (for example, a pendulum) to display units (for example, clock hands) include electronics, hydraulics, fluidics, and mechanics. The field of electronics comprises the study and use of systems that operate by controlling the flow of electrons (or other charge carriers) in devices such as thermionic valves and semiconductors. ...
Table of Hydraulics and Hydrostatics, from the 1728 Cyclopaedia. ...
Fluidics is science and technology of the application of a fluid or compressible medium to transmit energy and signals. ...
Mechanics is the branch of physics concerned with the motion of physical bodies, the forces that cause or limit these motions, and the forces to which bodies may, in turn, give rise. ...
A problem with using a conventional gear train (which has been the standard mechanism for the past millennium) is that gears necessarily require a ratio relationship between the timing source and the display. The required accuracy of the ratio required increases with the amount of time. (For instance, for a short period of time the count of 29.5 days per lunar month may suffice, but over 10,000 years the number 29.5305882 is a much more accurate choice.) A gear train is a set or system of gears arranged to transfer rotational torque from one part of a mechanical sytem to another. ...
In lunar calendars, a lunar month is the time between two successive similar syzygies (new moons or full moons). ...
Achieving such precise ratios with gears is possible, but awkward; similarly, gears degrade over time in accuracy and efficiency due to the deleterious effects of friction (which is to say, they get smaller. Smaller gears move faster, throwing precise calculations seriously out of joint). Instead, the clock uses binary digital logic, implemented mechanically in a sequence of stacked binary adders (or as Hillis, their inventor calls them, serial bit-adders). In effect, the conversion logic is a simple digital computer (more specifically, a digital differential analyzer), implemented with mechanical wheels and levers instead of typical electronics. The computer uses a 28-bit number representation, with each bit represented by a mechanical lever or pin that can be in one of two positions. This binary logic can only keep track of absolute time, like a stopwatch; to convert from absolute to local solar time (that is, time of day), a cam subtracts (or adds) from the cam slider, which the adders move. It has been suggested that Frictional force be merged into this article or section. ...
A cam is a projecting part of a rotating wheel or shaft that strikes a lever at one or more points on its circular path. ...
Another advantage of the digital computer over the gear train is that it is more evolvable. For instance, the ratio of day to years depends on Earth's rotation, which is slowing at a noticeable but not very predictable rate. This could be enough to throw the phase of the Moon, for example, off by a few days over 10,000 years. The digital scheme allows the number to be adjusted if the length of the day changes in a different way than expected.
Location The Long Now Foundation has purchased a mountaintop near Ely, Nevada, surrounded by the Great Basin National Park, for the permanent storage of the full sized clock, once it is constructed. It will be housed in a series of rooms (the slowest mechanisms visible first) in the white limestone cliffs, approximately 10,000 feet up the Snake Range. The site's dryness, remoteness, and lack of economic value should protect the clock from corrosion, vandalism, and development. Hillis chose this part of Nevada because it is home to a number of dwarf bristlecone pines, which the Foundation claims are nearly 5,000 years old. Ely is a city located in White Pine County, Nevada. ...
Great Basin National Park is a United States National Park, located in east-central Nevada near its border with Utah. ...
Binomial name Pinus longaeva D.K.Bailey The Great Basin Bristlecone Pine (Pinus longaeva) is one of the bristlecone pines, a group of three species of pine found in the higher mountains of the southwest United States. ...
Support The project is supported by the Long Now Foundation, which also supports a number of other very long-term projects, including The Rosetta Project (to preserve the world's languages) and the Long Bet Project. The Long Now Foundation, established in 1996 (or 01996), is a private organization that seeks to become the seed of a very long-term cultural institution. ...
The Rosetta Project is a global collaboration of language specialists and native speakers working to develop a contemporary version of the historic Rosetta Stone to last from 2000 to 2100. ...
The Long Bet Project was created by the Long Now Foundation to propose and keep track of bets on long-term events. ...
Alexander Rose was Hillis's primary collaborator on the first prototype clock. The other members of the design team for the first prototype were David Munro, Elizabeth Woods and Chris Rand. Musician Brian Eno gave the Clock of the Long Now its name (and coined the term "Long Now"); he has collaborated with Hillis on the writing of music for the chimes for a future prototype, a CD of which is currently being sold. [1] Brian Eno in 2006 Brian Peter George St. ...
External links This article or section does not cite its references or sources. ...
Vorbis is an open and free lossy audio compression codec project headed by the Xiph. ...
References - Stewart Brand, "The Clock of the Long Now: Time and Responsibility". Basic Books, 2000, ISBN 0-465-00780-5.
|
Feeds |
Contact