1. Doug's Atomic Clocks Details on Doug Hogarth's experiments with his atomic clock. http://www.niceties.com/atomic.html

FLASH: GPS SA discontinued MJD 51666! Maybe some satellites started a little earlier, but around midnight EDT (04:06Z) things really improved (even though the first URA value changes were not broadcast until a few hours later). On the first couple graphs, the UTC day started at about 39000 seconds so look starting around 53200 for less "noise" (smoother) somewhere near the average. Sorry that my TAC data doesn't include the sawtooth correction (which would smooth it more and probably chop a little off the top/bottom). The non-SA 58503A looks to be ~31ns peak-to-peak, near an order of magnitude stability improvement especially from around 100 to 2500 seconds averaging time. I'll integrate these couple below someday... I'm not especially comfortable with the term " atomic clock " because such devices really just know exactly how long a second lasts. The proper name for mine is the (Agilent) HP 5071A-001 Primary Frequency Standard (with high performance tube based on cesium or cæsium for those of you outside the US). The beginning of the second must be referenced somehow to the official international time which is typically UTC(BIPM). I also have another "atomic clock", the HP 5065A Rubidium vapor frequency standard (replaced some capacitors after discovering major problems on boards such as and ). Although Rb is considered "atomic", it must be referenced to a more official standard such as Cs (or GPS, etc).

2. Clocks And Time: Horology Site For Books, Magazines, Organizations, Museums, PC Horological directory of web sites for organizations, museums for clocks andwatches, mailing lists, book reviews and a watch and clock FAQ. http://www.ubr.com/clocks/

Museums Newsgroups Mailing Lists Organizations ... Pirate Pete's Pick of the WWW Luckman Four Star Award by Gordon T. Uber webmaster@ubr.com

3. Classic Antique Clocks, Et Cetera Antique clocks, grandfather, regulator and other mechanical timepieces bought and sold. http://www.classic-antique-clocks.com/

classic antique clocks, grandfather, regulator and other mechanical timepieces bought and sold antique clocks etc. French clocks Chelsea clocks Kieninger clocks mantel clocks Seth Thomas Sligh clocks Hermle Viennas wall clocks bracket clocks antique floor clocks English tallclocks store regulators banjo clocks skeleton gallery Authorized Sligh, Kieninger and Howard Miller Clock Dealers We Carry All Major Brands clocks from Ansonia Hermle Howard Miller Kieninger ... and cuckoos Lee Smith 135 Boston Post Rd. (Rt. 20) Wayland, MA 01778 4 miles west of Rt. 128 Phone (508) 358-5237 Professional Clockmaker Since 1972 member NAWCC Our goal is to offer you the best conditioned mechanical clocks available whether new, vintage, or antique at the best prices anywhere. We understand it is difficult to buy without personally examining a quality timepiece, so we invite you to visit our store. In fact, we do not encourage shipping one of a kind, expensive, and/or irreplaceable antique clocks unless the buyer has seen the clock in our store and has received our professionals' instructions those instructions that are particular to that clock's proper set-up and care. Please call us in advance if you are interested in seeing a particular era or style. We are New England's highest volume dealer of contemporary "Grandfathers", and sell a significant number of antique tallclocks as well.

4. CESIUM ATOMIC CLOCKS Kinds of cesium clocks, with pictures, plus a description of their operation andthe science behind them. http://tycho.usno.navy.mil/cesium.html

Cesium Atoms at Work "...till like a clock worn out with eating time." John Dryden (1631-1701) The 1955 Cesium Atomic Clock at the National Physical Laboratory, UK. It kept time to a second in 300 years. A "cesium(-beam) atomic clock" (or "cesium-beam frequency standard") is a device that uses as a reference the exact frequency of the microwave spectral line emitted by atoms of the metallic element cesium, in particular its isotope of atomic weight 133 ("Cs-133"). The integral of frequency is time, so this frequency, 9,192,631,770 hertz (Hz = cycles/second), provides the fundamental unit of time, which may thus be measured by cesium clocks. Today, cesium clocks measure frequency with an accuracy of from 2 to 3 parts in 10 to the 14th, i.e. 0.00000000000002 Hz; this corresponds to a time measurement accuracy of 2 nanoseconds per day or one second in 1,400,000 years. It is the most accurate realization of a unit that mankind has yet achieved. A cesium clock operates by exposing cesium atoms to microwaves until they vibrate at one of their resonant frequencies and then counting the corresponding cycles as a measure of time. The frequency involved is that of the energy absorbed from the incident photons when they excite the outermost electron in a cesium atom to jump ("transition") from a lower to a higher orbit. According to quantum theory, atoms can only exist in certain discrete ("quantized") energy states depending on what orbits about their nuclei are occupied by their electrons. Different transitions are possible; those in question refer to a change in the electron and nuclear spin ("hyperfine") energy level of the lowest set of orbits called the "ground state." Cesium is the best choice of atom for such a measurement because all of its 55 electrons but the outermost are confined to orbits in stable shells of electromagnetic force. Thus, the outermost electron is not disturbed much by the others. The cesium atoms are kept in a very good vacuum of about 10 trillionths of an atmosphere so that the cesium atoms are little affected by other particles. All this means that they radiate in a narrow spectral line whose wavelength or frequency can be accurately determined.

5. Wooden Gear Clock Kits And Clock Plans. Featuring original wooden gear clocks, kits, and plans. http://www.wooden-gear-clocks.com/

Home Page Learn the Secrets of Time While Making a Lasting Heirloom. . . Build Your Own Wooden Gear Clock! If you love clocks and working with your hands, our wooden gear clocks will give you hours of creative pleasure and years of enjoyment as it graces your home. And what a conversation piece! People will have a hard time walking by your wooden gear clock without pausing to marvel at its wooden movement and listen to its warm, peaceful "tick-tock". ( See and hear the wooden gear clock in motion Your handmade wooden gear clock is destined to become a valued family treasure. Old World Meets New World in Our Wooden Clocks Our all wood clocks wed Old World craftsmanship with state-of-the-art technology. The wood movement is an original design by clockmaker Jeff Schierenbeck , based on clockwork principles that have endured for hundreds of years.

6. Earliest Clocks Water clocks were among the earliest timekeepers that didn t depend on the More elaborate and impressive mechanized water clocks were developed between http://physics.nist.gov/GenInt/Time/early.html

Ancient Calendars Early Clocks A Revolution in Timekeeping The "Atomic" Age World Time Scales and Time Zones NIST Time Services Bibliography Early Clocks N ot until somewhat recently (that is, in terms of human history) did people find a need for knowing the time of day. As best we know, 5000 to 6000 years ago great civilizations in the Middle East and North Africa began to make clocks to augment their calendars. With their attendant bureaucracies, formal religions, and other burgeoning societal activities, these cultures apparently found a need to organize their time more efficiently. Sun Clocks T he Sumerian culture was lost without passing on its knowledge, but the Egyptians were apparently the next to formally divide their day into parts something like our hours. Obelisks (slender, tapering, four-sided monuments) were built as early as 3500 BCE. Their moving shadows formed a kind of sundial, enabling people to partition the day into morning and afternoon. Obelisks also showed the year's longest and shortest days when the shadow at noon was the shortest or longest of the year. Later, additional markers around the base of the monument would indicate further subdivisions of time. Another Egyptian shadow clock or sundial, possibly the first portable timepiece, came into use around 1500 BCE. This device divided a sunlit day into 10 parts plus two "twilight hours" in the morning and evening. When the long stem with 5 variably spaced marks was oriented east and west in the morning, an elevated crossbar on the east end cast a moving shadow over the marks. At noon, the device was turned in the opposite direction to measure the afternoon "hours."

7. Mystical-WWW Clocks And History Crash course information about the history of clocks http://tmsyn.wc.ask.com/r?t=an&s=hb&uid=24312681243126812&sid=343126

8. The History Of Clocks Learn about the history of clocks and watches, and discover the evolution of timekeeping devices from the first primitive sundials to the ultramodern http://tmsyn.wc.ask.com/r?t=an&s=hb&uid=24312681243126812&sid=343126

9. Clocks And Time: Time Software For PC Personal Computers For Time Setting And Sy clocks and Time describes time software for PC personal computers for timesetting and synchronization, clock rate correction and time display. http://www.ubr.com/clocks/timesw/timesw.html

Time Software PC Time Software Functional Categories Time software falls into two major categories: (1) Clock time synchronization and rate correction, and (2) time displays. Synchronization programs set the PC clock to an external standard. Although some programs permit manual synchronization (to a radio time station or audible time signal), increasingly, they dial up national standards and automatically synchronize. Network Time Protocol (NTP) servers are other synchronization sources. The tendency today is to use Internet time servers, which are controlled by atomic clocks. Because PC clocks rarely have a correct rate (they lose or gain time significantly) it is useful to correct the rate with software that determines the rate error and then periodically corrects the time. In this way a typical rate error of several seconds per day can effectively be reduced to several seconds per month. This has the added advantage that synchronization need be performed less frequently. For a discussion of PC clocks see the paper RighTime tm A Real Time Clock Correcting Program For MS-DOS-Based Computer Systems by Tom Becker.

10. Attleboro Clock Co. Dedicated to research on antique clocks with Attleboro Clock Co. Attleboro Mass on the dial. http://attleboroclocks.com

Do you own or know of an antique clock that has Attleboro Clock Co., Attleboro Mass on the dial as in this picture? This web site is a data gathering point for Attleboro Clock Co. Clocks: Attleboro Clock Company clocks are identified on the clock dial as being located in Attleboro, Massachusetts. However, there has never been an Attleboro Clock Co. in Attleboro, Mass. Very little is known about the Attleboro Clock Co., and there are very few Attleboro Clock Co clocks still in existence. If you have any information about the Attleboro Clock Co., or even theories that are different that those expressed here, please provide comments to me at Jerry Baker One of my primary goals in to collect information on as many Attleboro Clock Co. clocks as possible. If you have an Attleboro clock, please take the time to complete my questionnaire on your Attleboro Clock Co. clock. I am especially interested in the city and state of where the clock came from (to the best of your knowledge). All the photographs on all pages of this web site are "thumbnails" and can be enlarged by double clicking on the photo (use your browser's "back" button to return to this screen after enlarging the thumbnail picture).

11. The World Clock - Time Zones Current time in tables of places in the world. Can be sorted and otherwise customized. Includes meeting planner and other timerelated tools. http://tmsyn.wc.ask.com/r?t=an&s=hb&uid=24312681243126812&sid=343126

12. Internet Clock, Counter, And Countdown A collection of Internet (web, mostly) clocks, Counters, Countdowns, Timers.National debt, world and US population, death, military spending, doomsday, http://www.panaga.com/clocks/clocks.htm

Internet Clocks, Counters, and Countdowns Permanently Featured Links Temporally Featured Links (Alternate) Time Systems Doomsday ... Vanity Page (Links to this page) Permanently Featured Links The Millenium Clock The Long Now Foundation Daniel Hillis rocks! The Original Doomsday Clock The Bulletin of the Atomic Scientist (Alternate) Time Systems 28 Hour Day www.dbeat.com a new clock for a new age AtTime a ?freeware? Internet Time tool, includes centibeats! Black Hole Time I linked to that, so I could link to this BrainTime wetware of time perception New Scientist Chrons current chron time a decimal/metric time Daylight Saving Time deil.lang.uiuc.edu Where does that hour go? Daylight Saving Time www.geosys.com Daylight Saving Time, Australian A thorough guide to Australian DST Daylight Saving Time Protest Page fight the power Daylight Saving Time, California's explanation Calif. must always be different ... Decimal Time LOTS of nice clocks, systems, and info Decimal Time Society You gotta read up on Decadeciland Digital Time NDST not sure I get it Geologic Ages of Earth History it's sloooweerrr Geologic Time Machine it's sloooweerrr Global Standard Time (GST) Xtime definition Government Time, US

13. Earliest Clocks Early clocks. Not until somewhat recently (that is, in terms of human history) did people find a need for knowing the time of day. http://tmsyn.wc.ask.com/r?t=an&s=hb&uid=24312681243126812&sid=343126

14. U.S. And World Population Clocks - POPClocks US world population, current population estimates for the United States and theworld, population clocks. http://www.census.gov/main/www/popclock.html

Please take our Customer Satisfaction Survey U.S. and World Population Clocks - POPClocks Population Clocks U.S. World 07:09 GMT (EST+5) Sep 20, 2005 NOTE: The U.S. POPClock has been recalibrated to be consistent with Census 2000 data released on 12/28/2000. See the Detailed POPClock Pages for more information: U.S. POPClock World POPClock RSS Feed: US and World Population Clocks What's this? Source: U.S. Census Bureau, Population Division Internet Staff (Population Division) Last Revised: September 07, 2005 at 01:58:21 PM Census Bureau Links: Home Search Subjects A-Z FAQs ... Contact Us

15. KVCKVC Engraved desk accessories, clocks, picture frames, baby gifts, and sterling silver items. http://www.kvckvc.com

Tel: 561-204-3778 Fax:561-204-3712 293 Berenger Walk, Royal Palm Beach, FL 33414 Welcome to www.KVCKVC.com / KVCFL, Inc. a complete engraving services site. 48 hours or faster turn around on most jobs established in 1992, we are working for the top retailers, corporate and jewelers in New York City and throughout U.S., KVC offers a complete line of custom engraving services and custom cut plaques. Our Company has the experience to back up and increase your sales with personalized engraving services. FREE Return shipping , via UPS Ground Service anywhere in the US on all orders over FREE Mock-Up and Estimate via FAX! Quantity Discounts Whether you need 1 item engraved, or 10,000. we can accommodate your needs! call us at telephone number 561 204-3778 Business Hours M-F 10am-6pm EST shipping address: KVCFL, Inc. 293 Berenger Walk Royal Palm Beach, FL Tel: 561-204-3778 Fax: 561-204-3712 Email: kvckvc@aol.com Please check back SOON for UPDATES!!! Search Engine Optimization and Free Submission

16. Time Clocks USA - Timeclocks, Timecards And Software Sales, service and supplies for timeclocks from Amano, Lathem, Rapidprint, and Acroprint. Also PC based ID badge time systems. USA only http://www.timeclocksusa.com/

Homepage My Account View Shopping Cart Checkout Call us @ 1-800-605-7308 PC Based Computerized Electronic Mechanical ... Click here to add Timeclocksusa.com to your favorites! .: Welcome :. Welcome to Time Clocks USA. Whether you represent a large corporation, or a growing small business, we guarantee to have the perfect solution for your time and attendance needs! Shop Time Clocks USA .: Time Clocks :. We have a wide selection of timeclocks from PC Based systems, like Novatime, to mechanical standards like Lathem and Amano. .: Time Stamps :. We stock the best brands! Amano, Rapidprint, Widmer and Simplex are guaranteed to exceed your expectations! .: Master Systems :. .: Accessories :. Whether you are looking for replacement ribbon or a motor for your time clock, you have come to the right place! Service with a Smile Click here for savings!

17. Clock History The minute hand was invented by Jost Burgi ancient timekeeping - sun and water clocks - mechanical and quartz clocks - time standards - time zones. http://tmsyn.wc.ask.com/r?t=an&s=hb&uid=24312681243126812&sid=343126

18. U.S. And World Population Clocks - POPClocks US world population, current population estimates for the United States and theworld, population clocks. http://www.census.gov/ftp/pub/main/www/popclock.html

Please take our Customer Satisfaction Survey U.S. and World Population Clocks - POPClocks Population Clocks U.S. World 07:09 GMT (EST+5) Sep 20, 2005 NOTE: The U.S. POPClock has been recalibrated to be consistent with Census 2000 data released on 12/28/2000. See the Detailed POPClock Pages for more information: U.S. POPClock World POPClock RSS Feed: US and World Population Clocks What's this? Source: U.S. Census Bureau, Population Division Internet Staff (Population Division) Last Revised: September 07, 2005 at 01:58:21 PM Census Bureau Links: Home Search Subjects A-Z FAQs ... Contact Us

19. Artistic Minerals Eggs And Spheres, Nature Photography And Whimsical Wall Clocks Specializing in desktop and wall clocks, photographic wall art, and gem and mineral objects. http://www.art-clocks-etc.com

Artistic Mineral Eggs, Spheres and ... Artistic Mineral Eggs, Spheres and Crystals Mineral Eggs and other finds from around the world. Malachite Eggs Picture Jasper Eggs Lapis Lazuli Eggs O ur Earth Treasures include Malachite Eggs, Lapis Lazuli Eggs and Thumbstones, Picture Jasper Eggs, Rose Quartz Eggs and Thumbstones, Serpentine Eggs , Fluorite Tablets, Bloodstone Eggs, Celestine Eggs, Jade Eggs, Angelite Crystals and Snowflake Obsidian Palmstones and Thumbstones and a selection of high grade tumbled rocks. Photographic Nature Art Natural and Abstract Framed Photography "Wild Pink Rose" "White Jewel" "Pink Dahlia" H igh quality framed photographs featuring whimsical, colorful building details, flowers including wild Rose, white Jewel, pink Dahlia, California Poppy, purple African Daisy and white Morning Glory, mosaic and concrete sculptures from Taos, New Mexico and our tranquility set which includes a tree, flower and a beach and sea scene. Whimsical Desktop and Wall Clocks in 4 frame styles Desktop Clocks Wood Wall Clocks Acrylic Wall Clocks Our online store is fully secure and we accept all major credit cards. Orders ship within 1 -3 business days.

20. Howard Miller Home. Our Products. Floor clocks. Mantel clocks. Wall clocks. Tabletop clocks Rosewood Frames. Memorial clocks/Urns. Search for http://tmsyn.wc.ask.com/r?t=an&s=hb&uid=24312681243126812&sid=343126

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