I didn't want to do this in this forum, but since I feel you brought into the debate important aspects that deal with the SI system framework *itself* I felt this *particular* discussion should be tolerated here.
But, if not, Mr. moderator, please let me know and I'll continue this thread in private with whomever would be interested in proceeding, please. Thank you kindly. On Mon, 16 Feb 2004 15:48:10 Bill Hooper wrote: ... >CirgreeSys wrote: >> A strong case would have to be made towards adopting a metric time. >> :What are the advantages of metric time. >> :What are the disadvantages of metric time. >> >That all depends on what you MEAN by metric time. > Bill is making a very sensible introduction here, indeed a very pertinent question, but I feel we need to address some of his academic points he depicted below. >Consider: > >The day is a physical phenomenon (identified as the period between some >daily event and the next occurrence of that daily event (sunrise or >solar noon or some such event). > >The day is NOT CONSTANT in duration. > >There is no way that a precise definition of a basic time unit (like >the SI second) could be defined in terms of the length of a day (even >when averaged over some longer period of time). > Excellent. Very well put. There can be no arguments here. However, you mentioned below (later on) that it would be ok to be content with an *approximation* to that concept (of a day)! I'll tie this up to what I mean a little later below. >The question, therefore is, how does ANY proposed so-called "metric >time" define its basic unit? Without an answer to this question, no >reasonable discussion can be conducted about the merits of any metric >time scheme. > Fine. Valid point. BUT we will make a proposal to address that, please stay tuned below. >Any proposal to define new units or redefine old units must necessarily >come AFTER it has been decided how to define the basic unit upon which >all the other units in that system are to be based. > Indeed. The redefinition of the second would evidently be stated as another fraction of the speed of light so that its duration would meet what a *precise* (or as close to it as practically possible) 0.864 of the present second would translate to! In other words, in essence we'd be meeting your requirement above. Let's not forget that any *size* definition is (and always will be, BTW!) arbitrary. Now, as to why change such fraction, as opposed to the present one, will evidently hinge on the advantages of doing so! ;-) >QUESTION: How many seconds should there be in a day? >ANSWER: That depends on how big your second is. Define your second. > Agreed. Therefore, fine, let's adopt the definition as stated above to satisfy your academic requirement. >The most recent proposal seen here for "metric time" defines the second >as 1/(100000) of one day. As noted above, the day is not constant. >Thus, the above definition of a second gives us a NON-CONSTANT SECOND. >That is totally unacceptable. > Totally agreed! The "new" second should NOT be defined thusly, but like the present second is, i.e. some fraction of the speed of light that would be very carefully selected to match 0.864 of the present second's duration! (and I don't care if the end result ends up being 0.8639999999... or 0.8640000001 or something like that of the current second's duration, if you know what I mean) >SI does not seek to reconcile the unreconcilable here. Instead, it >defines a second precisely, with no reference to the unreliable day >length. Agreed, no discussion here! > Then, astronomers and others measure the day and find it is >APPROXIMATELY 86400 seconds long - approximately, not exactly, and >variable not constant. > So, by the same token, such individuals would find that it is *approximately* 100 000 seconds long, etc... ;-) >If one wishes to define a time unit called a "day" as 24 hours of 60 >minutes with each minute being 60 seconds long, it will be >approximately equal to the length of a real day and GOOD ENOUGH for >most practical daily purposes. So, continuing on your line of thought, Bill, if one wishes to define a time unit called a "day" as 100 (or 10 or 1 000, whatever) units of so many "decimal quantity" of sub-units..., it will be approximately equal to the length of a real day and GOOD ENOUGH for most practical purposes!!! The continuation of your paragraph below would follow (evidently...). But the advantage that would remain of this change is that one would finally get rid of a nagging Babylonian legacy and bring this aspect TOTALLY in line, theoretically and academically, with the rest of the other fundamental concepts that serve as a critical backbone of the SI system! The scientists can add a leap second or >so every once in a while to keep things neat and the man in the street >does not need to worry about it. > Now, finally, your last thought below. >If you don't like the 24-60-60 scheme for dividing the 86400 second day >into parts, then devise another one; BUT DON'T CHANGE THE LENGTH OF THE >SECOND. You could divide the time unit day into parts that are 86.4 and >1000 as follows: >1 day (time unit) = 86.4 kiloseconds, 1000 seconds = 1 kilosecond. > IF we implemented the above-proposed change there would be no 24-60-60 trash anymore! Evidently, the only advantage of the status quo is that nothing would change. However, realistically, I find it infeasible to adopt this division as proposed, i.e. 86.4 ks. Such "division system" would unfortunately be largely rejected as the number 86.4 is a real nuisance, a lot more than the 7-day weekly cycle even! To wrap this up, why I thought this should be discussed here despite calls of NOT discussing metric time? Simply because the REAL discussion here is NOT about metric time actually, but about **the SI framework** itself. What do I mean? Simple, the SI system is built around some fundamental concepts: 1) decimality 2) consistency 3) coherence among others. It doesn't really matter that (one of, actually!) the *flaw(s)* we found here happened to have been the definition of the second. For the SI system to REALLY enjoy academic "fullness" it would have NO CHOICE but to (ultimately) deal with some of its residual flaws that unfortunately crept into it. Historically, the evolution of this remarkable system followed a sequence of "philosophies" that didn't quite meet the challenge yet of what should be met by the creation of a system of units. Unfortunately for some reason no one stopped to think about this before proceeding and the "metric system" evolved mostly like a fix-up of a very "raggy" situation instead of developing this thing from the ground up anew! Had this *conceptual* work been done and the metric system would NOT have suffered so many revisions in it, like CGS, MKS, whatever... And the last aspect that makes this post all that important is that people here who are largely against such discussions may not realize that the "enemy" of the SI DOES have a lot of reason to shoot our plans of metrication down because they've spotted such inconsistencies and flaws in it to justify their defending THEIR status quo. So, let's face it, folks, (and food for thought), can we *really* say we're being ANY different from them after all?... I mean I'm evidently ALL for metrication, but I certainly would feel A LOT more confident and comfortable in doing so IF we were REALLY serious about this business of measurements. In other words, we would trounce the enemy and ALL its arguments much more effectively if "the product" we were selling was a *PERFECT* (or VERY near perfect) one, one that would be VERY RIGOROUSLY scientifically defined AS A SCIENCE BRANCH ITSELF, with undisputed tenets like logic and math have. THEN, the ilks of the BWMA folks would finally be trashed into the garbage bin where they deserve to be, because THEN they'd unquestionably be regarded as a bunch of mediocre individuals who really don't know squat about science, PERIOD! Regards, Marcus >================================ >More discussion is possible but I promised myself (and you) I'd quit >before this got even longer than it already is. > >Regards, >Bill Hooper >Fernandina Beach, Florida, USA > > ____________________________________________________________ Get 25MB of email storage with Lycos Mail Plus! Sign up today -- http://www.mail.lycos.com/brandPage.shtml?pageId=plus
