Talk:Clock

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Contents

[edit] Clocca

The introduction says that clocca is Celtic, but the first sentence of 1.3.1 (A new mechanism) states that it is Latin. Could someone who knows what he is talking about clarify or correct? (ChrisMP1 19:28, 24 September 2007 (UTC))

[edit] What about potato clocks?

Shouldn't there be a potato clock article? I mean, there are links to articles about various obscure forms of clocks. There doesn't seem to be an article on potato clocks! You know, those science-fair things that are basically clocks powered by potatoes? How does that work? I really think there should be a potato clock article (or a section on potato clocks in this existing one)4p0s713

—The preceding unsigned comment was added by 71.252.20.231 (talk) 20:03, 12 May 2007 (UTC).

That's just an electric clock powered by a potato battery. Just a gimmick, there's nothing notable going on there. Paul Koning 13:04, 13 May 2007 (UTC)

[edit] History Questions

Weren't the first town clocks maintained by hand?

How else?
Or do you mean some person rang a bell guided by psalm-singing or a sandglass? Kwantus 22:18, 2005 Feb 17 (UTC)
In the West, towns were (often, usually ?) not the first time-keepers, monasteries were. Some poor monk was responsible for waking the others up. There is some evidence that, in the West, the alarm clock mechanism, needed to wake up the bell-ringer, preceded the mechanical clock mechanism. Mechanical clocks were invented perhaps 1250-1300AD. Many of these early clocks were installed in town centers, but this is well before the Industrial Revolution. DCDuring 01:00, 27 August 2007 (UTC)

I've noticed that when clocks are on display in stores they are almost always set at 10:10. Does anyone know why this is? My grandfather read that there was some sort of significance to this in a trivia book but he can't remember what it was.


Someone should really correct this page, and i don't have the skill to do so

a clock strikes the hour! a timepiece does not. you watch is a time piece, your grandfather clock is a clock!


--- I keep seeing that the length of an hour depended on the season (if away from equator, anyway) -- On sundials, was this done by tilting the face?

In some cultures daylight was 12 daylight hours and night 12 nighttime hours. () I don't know what they did with sundials, or why we wound up with the 12s in the middle of the intervals. Kwantus 22:18, 2005 Feb 17 (UTC)
The hour was DEFINED as one-twelfth of the time between sunrise and sunset in each place in the Middle Ages and, I think, in Classical times. It may go back to Babylon, a civilization in which the numbers 360, 60, and 12 had great meaning in astronomy and time-keeping. Or it may go back farther, to Egypt. DCDuring 00:40, 27 August 2007 (UTC)

How did the earliest mechanical clocks work -- I see gears. Did they use hanging weights to provide the energy?

Yes. They were simple, and give the constant torque needed by a verge (although that was probably not keenly understood). Kwantus 22:18, 2005 Feb 17 (UTC)

In the History section there's a paragraph that begins

The earliest clocks

Shouldn't it start

The earliest table clocks
--> it says "The earliest clocks *that survive in any quantity*"
Q2.2: "any quantity" is so vague - Are we talking about mass production, or even clocks that are very much alike? Is this to say that town clocks did not survive in "any quantity" - wouldn't the standard of "any quantity" be different when there is only one per town? - is there any expectation that town clocks would be nearly identical? Who really cares about how many survived when they want to know how the technology developed? How small would these table clocks be & how long would they run before needing to reset the weights - or were springs used? --JimWae 18:30, 2004 Dec 10 (UTC)
-->

I've added this external link

--JimWae 02:42, 2004 Dec 10 (UTC)

I'd like to see the History section improved. There's a hole in it - the early history of the mechanical clock has been glossed over somewhat, and the human intellectual achievements aren't mentioned. I've been reading John North's "God's Clockmaker: Richard of Wallingford and the Invention of Time", and I suggest that a precis of his less contentious material be included here. Briefly: around 1250 - 1280: fusion of water clock technology and experience, weight/gravity powered energy, oscillating striker from bell ringing devices, and the desire to produce both 'powered astrolabes' and 'automated signalling/alarm devices'. By 1280/1290, mechanical clock-making is beginning, judging from increasing mentions in English cathedral records: 1283 Dunstable Priory: big clock installed above rood screen (so probably not a water clock). 1290: "repair of clock" in Norwich. 1292: Canterbury Cathedral has a 'great horloge'. The 1322 clock in Norwich (presumably a replacement) was a huge (2 metre) astronomical dial with automata and bells - cost a fortune. And there should definitely be a mention of the great St Albans Clock of Richard of Wallingford, which was fully described by its builder. It had sun and moon dials, star map, wheel of fortune, showed the times of the tide at London Bridge, and had a 'dragon' plate which indicated the likelihood of an eclipse. North argues that this English activity predates the Italians, which is probably just scholarly rivalry (against Dohrn-van-Rossum's pro-Italian views), but also suggests that these expert clockmakers may have travelled around Europe as 'consultants'. :-) Mention should also be made of Dondi's incredible astrarium of 1364.

Cormullion 09:26, 23 April 2006 (UTC)

I had a go at writing a better early history. Cormullion 18:01, 8 May 2006 (UTC)

The History section is getting better (I hope) - but longer - and it's still incomplete. Perhaps it's time for the History of the Clock to be spun out of this main article into a separate article which could be better organized and cover the history of clocks better. Anyone think this is worth doing? Cormullion 09:39, 11 June 2006 (UTC)

I agree the history is getting a bit long, but I'd vote for at least an outline history here. One way to clean it up would be the 'hideable outline' form (don't know what it's called) I've seen on other pages. Clock history would appear in a box where only the section headings appear in an outline; clicking on one expands that section. Another idea: the topic Mechanical clock is currently unused; it redirects to Pendulum clock, which is only one type of mechanical clock. The early history referred to above could be spun off there. --Chetvorno 14:28, 11 August 2007 (UTC)
I really like the idea of having a Mechanical Clock article that contains the history and prehistory of the mechanical clocks and doesn't get lost in all the older and newer means of time-keeping, which each merit their own articles as well as a unifying piece that relates each technology to the other in history, geography, and technical influence. DCDuring 01:00, 27 August 2007 (UTC)

[edit] old top

I've never heard of an "ideal clock" but you learn something every day! [1]

Elsewhere Andre Mirabelli presents this definition:

The ideal clock is the recurrent process that makes the most other recurrent processes periodic.

I found this somewhat confusing at first. I suspect that part of the confusion is the attempt to simultaneously define a clock and an ideal clock. Here is an approach by Charles Francis that breaks it into two definitions:

A clock is a repeating process and a counter.

A good clock is one whose mechanism enables you to say that each time the process repeats, it repeats under physical conditions identical to the last.

- Jeff

I wrote a quick paragraph on longitude; not sure if hour-candles are worth mentioning here (probably not worth a separate article). Vicki Rosenzweig

The problem with the definition of Charles Francis is that "identical" "physical conditions" are themselves defined in terms of clocks and rulers. That is why one needs statistical definitions of clocks and rods to develop thought experiments that can non-circularly reconstruct physical theories. Andre Mirabelli

After talking with Andre off-line we sketched out an approach to the clock definition:

  • A clock is a recurrent process and a counter
  • A good clock is one which, when used to measure other recurrent

processes, finds many of them to be periodic.

  • An ideal clock is a clock (i.e., recurrent process) that makes the most

other recurrent processes periodic.

  • A recurrent process is ...
  • When we say that one recurrent process makes another recurrent process

periodic we mean ...

There are still some gaps to fill in --Jeff 23:11 Nov 7, 2002 (UTC)

The definition of an ideal clock as one that makes most other recurrent processes periodic is very bad even if you substitute "apparently periodic" for "periodic". An ideal clock exposes all other apparently recurrent processes as not periodic (assuming they themselves would not make ideal clocks)!

Instead, I propose we define one type of clock A as better than another type B if different instances of type A clocks are statistically both more precise and more in agreement with one another in measuring intervals of time. Thus atomic clocks are better than grandfather clocks. An ideal clock is one that measures intervals of time with infinite precision and always agrees exactly with other clocks of the same type.

If I find no objection to this proposal by the next time the spirit moves me I'll edit the main page along these lines. - Heimdall 19:42 July 11, 2006 (UTC)

Analog and digital. According to the Wikipedia article on "digital", something is digital when it deals with discrete values, instead of a continuous spectrum of values. Some clocks are round with hands, but the hands go clunk-clunk instead of sweeping. Those clocks would then be digital! There are only a finite set of discrete values which the clock is (by design) capable of displaying.

So, I guess a clunk-clunk clock whose second-hand sweeps would be two thirds digital and one third analog, and since one third of the unit circle is two thirds of a pie, and since pie is tasty, and since I taste, and since I am either am or not, and since Being is digital, clocks are man-made, except when they're not.

-Todd

That's so beautiful. --DavidCary 06:30, 13 Jan 2005 (UTC)

[edit] counterclockwise clock(s)

Except for novelty items all clocks turn in the same direction these days. It wasn't always so; the Jewish clock in Prague is the best known example but there must surely be more (I cannot however find the German church one I distinctly remember seeing once).

Yes, I saw a counter-clockwise clock inside a famous church in Italy. (I'll probably remember the city and the church at the most inconvenient time to run back and edit Wikipedia). Also, ordinary sundials, when they happen to be in New Zealand, have a shadow that goes counter-clockwise around the gnomon. It has something to do with being south of the Tropic of Capricorn. --DavidCary 06:30, 13 Jan 2005 (UTC)

[edit] time in Europe

It should be noted that the way to tell the time is different in different regions; 17:30 would be half past five in English but 'half zes' (half TO the next hour) in Dutch (the Germans use the same method). This is a wellknown source of missed appointments >;^)

Another thing; only last century there were three distinct times being used on the European continent;

 - Greenwich mean time in Belgium (and the UK)
 - European time (Germany and elsewhere), one hour offset from GMT
 - Dutch (Amsterdam) time, 40 minutes off GMT and 20 minutes off European time

The Amsterdam time disappeared in WW II after the German occupation. Before the Amsterdam time became the standard there were local times (which made railway timetables really hard to figure out).

[edit] "clock signal"

Most digital circuits rely on a "clock signal".

If we had a good definition for "clock signal", then the definition

  • A clock is a recurrent process and a counter.

could be reduced to

  • A clock is a "clock signal" and a counter.

--DavidCary 06:30, 13 Jan 2005 (UTC)

I took out "This word has led scholars to believe that these earliest timekeepers did not employ hands or dials, but ‘told’ the time with audible signals." Since surviving machines, eg that of Salisbury cathedral, have no provision for hands, we know some early clocks lacked them. This may have been a matter of scale or practicality: a verge escapement would be pathetically inaccurate burdened with a large exposed hand sometimes loaded by rain or snow or wind. And it's a pain knocking holes in a Norman tower and climbing up to hang such a thing. On the other hand, bells were probably already on-site, relatively easily accessed, and could be heard in conditions a dial is invisible—in alleyways, at distance, darkness, bad weather.

Conversely, a household clock would likely have had a dial to save the bother of a strike train.

The linguistics - esp if the widely-believed etymology of "clock" is correct - is easily explained by the fact the first widespread contact with a mechanical timepiece was these church-tower clocks. Kwantus 22:18, 2005 Feb 17 (UTC)

[edit] Digital clock (formerly: I don't care what it's technically called)

I want to go to the article about digital clocks. I don't care what they are technically called. I can't find it. The purpose of Wikipedia is to provide facts, in a way that is accessible to anyone. Digital clock redirects here (to clock). Could someone please just figure out what they're called and make "digital clock" redirect to that article? Sorry for sounding harsh, but when you have to be an expert on something just to learn about it, it doesn't work. Twilight Realm 03:02, 27 September 2005 (UTC)

This article addresses both analog and digital clocks. It could probably use some more distinction, and it definitely could use some pics of digital clocks, but until there is a lot more detail about each, there's not much point in creating a separate digital clock article. I'll put this on my to-do list, tho. --Tysto 04:07, 29 September 2005 (UTC)
Added pic of a digital clock radio. I also have a fancy one with white noise settings as well as a pure digital clock with no radio. I'll snap them as well for a digital clock article. --Tysto 04:36, 29 September 2005 (UTC)

I think there's enough difference for either a separate article or at least a single section devoted to digital clocks. This is progress, though, which I appreciate. But what I was looking for when I first came to this article was some information on how it works. I wanted to use digital clocks as an example in an essay on electronic components. Unfortunately, Wikipedia failed me, which is quite unusual. But there's definitely a big difference in the way it works. At the bottom of the article is a very long list of different types of clocks. But even though there are many different, unique types, all of them (or almost all; I didn't check them all) are similar in that they are all mechanical. Though it acheives the same function, mechanical timekeeping is very different from electronic timekeeping. I know there's a lot of variety in methods of mechanical clocks: springs, pendulums, etc. Quartz clocks can actually be either analog or digital. But mostly they're very different, and deserve to be treated that way.

You may earn the same amount of money if you are a sports player, a celebrity, or the inventor of something revolutionary. But they aren't all grouped in a single article ("Rich People"), even if their income is the same. The method of earning it is completely different. Twilight Realm 01:09, 30 September 2005 (UTC)

I took several pictures of different kinds of digital clocks and uploaded them to Wikimedia Commons. I changed the "Displays" section to "Types" and expanded it to describe digital clocks more, then I created an separate main article for digital clock with the new pics. I think the "Ideal clock" section should be removed to its own article, since it seems to deal with an abstract scientific concept rather than a practical device for telling time, but then the article probably needs a bit of reorganization generally. --Tysto 23:20, 30 September 2005 (UTC)

[edit] Article about clock, but picture of watch?

I think that it's interesting that an article about clocks starts with a top picture of a "watch". I think a better top picture is in order. I like this one:

I think it's a lot more appropriate. Any other thoughts? Joe 15:49, 3 October 2005 (UTC)

Agreed. Twilight Realm 21:30, 3 October 2005 (UTC)

Okay, hearing no objection, I put the picture of a clock in the article about a clock and I put the picture of a watch in the article about a watch. Let me know what you think. Joe 02:02, 8 October 2005 (UTC)

[edit] cleanup?

does the article still need the cleanup tag' --Melaen 23:24, 10 January 2006 (UTC)


I removed "Al Gore is a bozo the clown fanboy" from the segment on water clocks if that's ok with everybody. - 12 March 2007

Perhaps someone could help cleanup the first paragraph under "A new mechanism". - May 6 2007

the external link * Personalised Clocks - Design and build your own clock is an advert not information —Preceding unsigned comment added by 82.16.14.74 (talk) 16:08, 4 January 2008 (UTC)

[edit] Symbolism in various cultures?

Someone at Talk:Vernal equinox mentioned that myths shouldn't be added to encyclopedic articles about the object in question, but I think it's perfectly valid to include if it's significant enough. This person mentioned that for many Chinese, it is considered unlucky to give someone a clock as a gift, as it symbolizes death for that person. What kinds of things do clocks represent in other cultures? Should this be mentioned in the article, if it's significant enough, even if it's only a mild aside (such as "Symbolism" or some other heading)? I'd even consider mentioning Salvador Dalí's The Persistence of Memory or somesuch... I dunno, just some ideas. JC 09:15, 15 February 2006 (UTC)

[edit] Types of clocks and See Also

These sections at the bottom seem a bit haphazard. Merge? Revise? Evertype 18:37, 17 April 2006 (UTC)

[edit] Clocks don't serve to measure years, months and so on?

The article states the following: "A clock [...] is an instrument for measuring time and for measuring time intervals of less than a day as opposed to a calendar". Then computers' clocks don't measure months? Computers have electronic calendars as part of their hardware? And, by the way, are calendars really used to measure time? Aren't they used more to know what day of the week a certain day is? MJGR 12:21, 22 August 2006 (UTC)

[edit] Clocks vs. timepieces

I have added brief references to the nature of "timepieces," which lack striking mechanisms, and noted that this distinction sets them apart from "clocks," which usually have bells or gongs that announce the passage of time. It is hoped that this distinction will be helpful to those who investigate timekeeping instruments and their useful characteristics. Jack Bethune 19:14, 27 August 2006 (UTC)

Well. OK, I won't try to rewrite this again! I don't feel that strongly. But I remain unconvinced that you can keep the distinction clear, either in this article or the rest of Wikipedia. In common usage, a clock is something that keeps time, not something that definitely makes a noise. And a timepiece is really just another way of saying 'clock' or 'watch'. I really don't think the two concepts are distinct anymore. And the phrases 'correct' and 'proper' imply a clear authority, which you should probably quote... - my response is "says who?" :-) Cormullion 20:53, 17 October 2006 (UTC)

Cormullion, although some might think it’s time to abandon the longstanding distinction between CLOCK (a striking timekeeping instrument with a bell or chime) and TIMEPIECE (a silent timekeeping device (e.g., a watch) lacking such an announcing mechanism), there is ample evidence that this traditional distinction remains a useful one still recognized in horology.

A sampling of clock reference books, clock glossaries, online encyclopedias and dictionaries, horological museums, premier auction houses, and current watchmaker websites confirms not only that this distinction is firmly established, but also that it is widely observed in daily practice. Here is a list of sources/links providing the necessary confirmation:

1. Some standard clock references defining timepiece:

“Clock is a word derived from roots meaning “bell,” so that if we want to be slightly pedantic we shall call a non-striking mechanism a Timepiece rather than a clock.” Eric Smith, Clocks and Clock Repairing (2nd ed.), TAB Books (1989), p. 48.

“TIMEPIECE. Any clock which does not strike or chime.” G.H. Baillie, O. Clutton, & C.A. Ilbert, Britten’s Old Clocks and Watches and Their Makers (7th ed.), Bonanza Books (1956), p. 307.

“Timepiece: A time-telling machine which does not strike.” Brooks Palmer, The Book of American Clocks', The Macmillan Co. (1979), p. 19.

“TIMEPIECE: a clock or watch which simply tells the time, without any additional complications, such as a striking mechanism.” Philip Zea & Robert Cheney, Clock Making in New England – 1725-1825, Old Sturbridge Village (1992), p. 172.

2. Another reference defining timepiece:

“Strictly speaking, a time-measuring machine without a bell is a timepiece.” Edgar G. Miller, Jr., American Antique Furniture, 1937, vol. 2, p. 862. [2]

3. Some online encyclopedias defining timepiece:

“A clock … also has a mechanism by which it strikes the hours on a bell or gong, whereas, strictly, a timepiece does not strike, but simply shows the time”:[3],

“Timepiece … an instrument for recording or showing the time, especially one that does not strike or chime, e.g., a watch or clock.” MicroSoft Encarta:[4],

4. Some online dictionaries defining timepiece:

“…a Timepiece type clock, with no striking train.” British Horological Institute:[5],

“Timepiece: a device (as a clock or watch) to measure or show progress of time; especially: one that does not chime.” Merriam-Webster Online:[6],

“Timepiece: A clock that tells time only and does not strike or chime”:[7],

“Timepiece A clock which does not chime or strike”:[8],

5. A sampling of major auction houses that differentiate timepieces:

Sotheby’s: [[9]],

Christie’s:[10],

6. The National Watch and Clock Museum refers to clocks and wristwatches that lack strike mechanisms as timepieces:

--On wristwatches as timepieces:[11],

--On Willard’s patented (non-striking) banjo design as a timepiece:[12],

--On Job Wilbour’s patented (non-striking) banjo design as a timepiece: [13]

7. A sampling of typical watch manufacturers routinely describing their products as timepieces:

Seiko:[14], and here: [15],

Rolex:[16], and here: [17],

Patek Philippe:[18]

Based on the foregoing evidence, perhaps we can all agree that it would be premature to dismiss what has been a useful timekeeping distinction among horologists for centuries, so that its inclusion in Wikipedia is not only legitimate but also helpful to those learning about clocks and other timekeeping devices. Jack Bethune 17:48, 25 October 2006 (UTC)

Great work, Jack! An impressive list. I have no problem with the theory. Perhaps I just want someone to say that the difference might be observed within 'horological' circles but isn't much observed much outside those circles... Like most people l'll still be referring to the items mentioned in the article as 'clocks', whether they're noisy or not. For example, the famous Shepherd Gate clock at Greenwich is never called a timepiece, and neither is the system clock on my computer... Cormullion 18:21, 26 October 2006 (UTC)
I tend to agree. I think the first quote above hits the nail on the head: "...if we want to be slightly pedantic we shall call a non-striking mechanism a 'Timepiece'." I don't have a problem with the distinction or anything... it just seems a bit pedantic. My clock radio doesn't have a striker, but I've never heard anyone called them "timepiece radios". Kafziel Talk 18:27, 26 October 2006 (UTC)

Every definition that defines timepiece as "a clock that does not strike", marks timepiece as a type of clock, not as something other than a clock --JimWae 19:09, 26 October 2006 (UTC)

Thanks, Jim, for placing the distinction where it belongs and for creating the synthesis needed in this discussion. A timepiece is indeed a type of silent clock, for those who want to learn a little horology from all the pedants contributing to Wikipedia, including this one. Thanks also to Cormullion and Kafziel for your keen observations as well, as the results achieved by our recent discussion will be of benefit to Wikipedia readers. Jack Bethune 20:45, 26 October 2006 (UTC)
In recognition of the valid points raised by all, I have proposed an improved description of "timepiece" to acknowledge the specialized nature of this historical term, which we all agree is generally not used by the public. Does this version produce a better perspective for the reader? Jack Bethune 11:10, 27 October 2006 (UTC)
Yes, much better! Thanks for the hard work, Jack. Cormullion 18:05, 27 October 2006 (UTC)


I do not think "true clocks..." (last paragraph in intro) will stand up to examination. My analog clock on the mantle is truly a clock, and so is the analog one on the wall in the office, and so is my digital alarm clock. Some people truly use time-clocks to punch in & out of work too --JimWae 18:59, 27 October 2006 (UTC)

- As well, the atomic clock at the university is also a clock. These are not misuses of the term clock, they are extended usages that differ from the origin of the word - and do not get me started on whether clocks measure time or are instruments for timing. --JimWae 19:41, 27 October 2006 (UTC)

To repeat myself: Every definition that defines timepiece as "a clock that does not strike", marks timepiece as a type of clock, not as something other than a clock. IF we are using sources for accepted usage of English, dictionaries are more authoritative than websites (composed by individuals who, for the most part, are unidentified) --JimWae 20:38, 12 September 2007 (UTC)

Complicating all this, we have watches that chime the hour. The primary distinction these days is between clocks (some of which make sound(s) to mark the time) & watches--JimWae 20:43, 12 September 2007 (UTC)

If timepieces were exclusively for silent devices, wouldn't English be left without a word for all devices used to mark time? Couldn't they all be timepieces? I think the order of presentation should show clocks as time-keeping devices that are not worn by people, with notation that some horologists (with source_ reserve that word for the subset of those devices that regularly make a sound to mark at least some hours (if not every hour & 1/2 h & 1/4 h)--JimWae 23:36, 13 September 2007 (UTC)

[edit] "Big Ben" caption

The caption for the picture of the clock tower of the Palace of Westminster - the tower is only colloquially (and incorrectly) referred to as Big Ben, which is actually the name of the clock's biggest bell. Jberanek 15:08, 24 October 2006 (UTC)

[edit] Protecting this page

Protecting this page is a good idea. This article seems to be the target of much minor vandalism. Cormullion 08:44, 11 February 2007 (UTC)

[edit] Clocks and Watches

We have a challenging question, does clocks and watches go tic before tock or tock before tic? Example: (tic tock, tic tock or tock tic, tock tic).--Storesonline 00:17, 3 March 2007 (UTC)-http://www.tictockclocks.com

[edit] Clocks "an instrument for measuring time"

Clocks don't measure time, time if defined by clocks. Clocks are a physical varible, according the June 2007 issue of Discover magizine and Ferenc Krausz, "So in a sense we cheat because what we really observe are physics variables as a function of other physical variables."

It also states " [Time] would work equally well if time ran backward. As far as we can tell, though, time is a one way process; it never reverses, even though no laws restrict it." -TheNinjaPirate 15:36, 21 May 2007 (UTC)


[edit] Moerou toukon

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[edit] Synchronizing to mains

Is it true that the power plant frequency is synchronized to an atomic clock? Everywhere? — Omegatron 02:38, 24 May 2007 (UTC)

No, but it is true in large power grids, because it is necessary to keep all the generators in sync. Small grids, for example small islands with their own Diesel generators, are unlikely to be synchronized to anything. Paul Koning 15:50, 24 May 2007 (UTC)

[edit] Suspect etymology

The intro says that the word clock "is derived ultimately (via Dutch, Northern French, and Medieval Latin) from ... Celtic words ...". I find that hard to believe; that line of derivation doesn't sound plausible from the point of view of historic linguistics. I know the Dutch and German cognates, but not the other ones. So I could believe a Germanic origin (if so, you'd find it in Anglo-saxon). If there are cognates in the Celtic languages and/or Latin, that would argue that it goes way back to proto-indo-european (which is not an attested language but can be reconstructed). That takes me beyond what I know of linguistics; I hope someone can fill in the details. Paul Koning 18:53, 12 September 2007 (UTC)

It didn't sound plausible to me either, so I looked it up, in Percival Price (1984) "Bells and Man", a fairly scholarly work. First, apparently metal-working technology good enough for bells is believed to have originated in central Asia and proceeded both East and West from there. The Celts may have been among the carriers of that technology and certainly used bells, mostly small, a lot. Celtic Ireland was an imporant stronghold of Christianity in the "Dark" Ages. The monasteries of Ireland were apparently the transfer point for the word from Celtic to Medieval Latin and for the use of bells instead of wooden knocking boards into Church usage. Interesting, eh? DCDuring 19:07, 12 September 2007 (UTC)

[edit] Shouldn't the verge escapement be mentioned?

In the section on the development of mechanical clocks (ambiguously titled 'A new mechanism') the escapement is just mentioned peripherally, and the verge escapement is nowhere mentioned. Every book on the origin of mechanical clocks I've seen says that the key invention that made them possible was the escapement, and that escapement was the verge escapement. Even though no one knows when or where it was first used, with one exception it was the only escapement found in early clocks, and it remained the only one for 400 years. Not only did the verge make possible the all-mechanical clock, it marked the switch from telling time with continuous processes (like flowing water in the Kaifeng tower) to repetitive, oscillatory processes (like verge & foliot) which are used today. I agree that other technological innovations necessary for mechanical clocks (such as power from falling weights) may have been ignored in the past, but to omit the verge leaves a big hole in the story. --ChetvornoTALK 08:49, 26 November 2007 (UTC)

Makes sense to me. Paul Koning (talk) 16:40, 27 November 2007 (UTC)

[edit] Clock /* */ Good clock /* */ Ideal clock

The present section Clock#Ideal_clocks is concerned with various notions of "clock" as "scientific principle" (or as may be put more concretely: as "thought-experimental definition" and "idealization"); appropriately closely related to the notion of "duration" (and consequently, how Duration is defined as a physical quantity).

A definition of a (any) "clock" in this particular context can be derived from how the notion of "clock" in turn is being used in the (Einstein's) definition of Time as "what the clock indicates"; where, as noted by Wheeler, these indicated instants "don't all happen at once" (but in particular order).

A (any) clock is accordingly a sequence (whose elements, "instants", serve as distinct indicators). (As far as the elements of a sequence can well be called "recurring in sequence", this is already reflected in the present section Clock#Ideal_clocks. However, an associated counter of sequentially recurring elements is not required -- not least because for any two distinct elements of the clock sequence, infinite other elements may have been indicated inbetween; thus rendering irreproducible any attempt at a sequential count of such elements.)

The notion of a "good clock" (vs. "bad clock") appears for instance in MTW#Gravitation_(book), Fig. 1.9. However, there it serves only to illustrate derived notions such as "force" or "freedom (from force)" or "uniform motion" etc. Considering attempts at thought-experimental definition of "force" etc. (such as Schelb, U. Foundations of Physics, Volume 30, Number 6, June 2000 , pp. 867-892(26)), and the familiar notion of Uniformity#Evenness_of_measure, therefore:

A good clock is a clock for which the duration between (pairs of) its instants has been measured (and may be suitably indicated, as proper time). (The description in the present section Clock#Ideal_clocks is plainly irreproducible: "periodicity" is a derived notion; "many other processes" is heuristic, not physics.)

Finally, the notion of an "ideal clock" appears separately in MTW#Gravitation_(book), sect. 16.4, involving the notion of "number of ticks", which in the corresponding sketches are illustrated as ping counts (counts of roundtrip signals being exchanged between two clocks). Accordingly:

An ideal clock is the thought-experimental setup and procedure which serves to define duration as a physical quantity. (It involves taking ping counts between certain participating clocks.) (The present section Clock#Ideal_clocks states this initially, but then goes on to give a different, heuristic description.) (The description stated in MTW#Gravitation_(book) is of course not a reproducible definition either, since it requires the derived notions "free" and "geodesic".) Frank W ~@) R 21:23, 19 December 2007 (UTC)

[edit] Clepsydra

Considering that clepsydra is a Greek word, a plural with "ae" doesn't look right. That's a Latin plural ending, not a Greek one. Paul Koning (talk) 16:29, 14 April 2008 (UTC)