There is no dispute as to the value of velocity of light adopted by BIPM/CCU and need not change till 'new interval for *decimal or otherwise* second are adopted. I had only drawn the attention of scholars the an improved value of this 'constant' had beeb reported in the TIME Magazine (1972), but remained ignored! Well, Brij Bhushan Vij <[EMAIL PROTECTED]>
>From: "kilopascal" <[EMAIL PROTECTED]> >Reply-To: [EMAIL PROTECTED] >To: "U.S. Metric Association" <[EMAIL PROTECTED]> >Subject: [USMA:21631] Re: Velocity of Light >Date: Sat, 10 Aug 2002 13:25:52 -0400 > >2002-08-10 > >The metre is defined as the distance light travels in a vacuum in 299 792 >458 s^-1. Thus, the speed of light is EXACTLY 299 792 458 m/s. There is >no >other speed. Forget this 299 792 456.2 m/s! There is only one definition >as stated above. What is so difficult about this? Come on...get with the >program! > >It is very common to give rounded figures for any measurement when reported >by the media. It is done that way to make the reading simpler. It is not >to be taken as gospel. Don't get hung up on this. I frequently us 10 >m/s^2 >for the standard acceleration to gravity instead of 9.806 65 m/s^2. If a >more exact number is need for a specific purpose, it will be used. But, >when approximation is ok, we always use the rounded figures. Even the >FFU-ists do it. > >Light Year? Miles per second? What is this nonsense? These are not SI >units? We use metres here, with the proper scaling prefixes. We really >don't care how many miles per wigwam the speed of light is. > >Please help us to get the US metricated and not waste your time or ours >with >talk of redefining the metre. Leave the definition of the metre and second >to the experts at the BIPM. Talk of changing the metre and second will >only >confuse people who we are trying to convince to accept SI as a better >system >than FFU. > >John > > > > > > > >----- Original Message ----- >From: "Brij Bhushan Vij" <[EMAIL PROTECTED]> >To: "U.S. Metric Association" <[EMAIL PROTECTED]> >Sent: Friday, 2002-08-09 19:32 >Subject: [USMA:21617] Velocity of Light > > > > Hi All: > > Using the term 'speed of light' does not fit into the SI-practice; >when >it > > is desired to link or express it with the definition of LENGTH unit >*Metre*. > > In my humble way, I tried to give the BEST value for velocity of light >and > > presented a way to:MEASURE LENGTH UNIT USING TIME TAKEN TO TRAVERSE THE > > DISTANCE *METRE*. > > ONE light year is a measure of 'distant stars'. This by definition is >the > > distance traversed by light in a period of 'one tropical year'. >Scientists > > working under Dr. Kenneth M.Evanson at National Bureau of Standards >bettered > > the 'measured' velocity of light to *New Accuracy* of 299.7924562 x 10^8 > > metre per second (existing time scale). This figure work to >186282.39593276 > > miles per second. The rounded value reported by CNN (300000 km/s)and > > resented by many in their communication to usma is meant for the > > understanding of common man and not for scientific world. > > This bettered value was reported in the TIME Magazine, New York in >their > > issue dated 4 December 1972; and I re-worked to express *METRE in terms >of > > time interval* in my base work: The Metric Second published by Indian > > Standards, New Delhi in their Bulletin V25 N4 (1973 April), about which >I > > have referred earlier. > > In the *NEW* aspect, the METRE being proposed shall be 1.11194886884 >times > > the 'defined metre' and correspond to: *the distance traversed by light, >in > > vacuum, during the time interval 1/97059575.22th of the 'decimal >second'*. > > Time conversion factor = 0.36; and distance conversion factor = > > 1.11194886884 OR their reciprocals shall go a long way in re-evaluation >of > > the "derived units and quantities", linked with Time and Length Units. > > Brij Bhushan Vij <[EMAIL PROTECTED]> > > > > > > > > >From: [EMAIL PROTECTED] (Joseph B. Reid) > > >Reply-To: [EMAIL PROTECTED] > > >To: "U.S. Metric Association" <[EMAIL PROTECTED]> > > >Subject: [USMA:21588] Re: Speed of Light > > >Date: Thu, 8 Aug 2002 19:54:55 -0400 > > > > > >Louis Jourdan wrote in USMA 21581 > > > > > > >At 11:00 -0400 8/08/2002, Joseph B. Reid wrote: > > > >>I think that M.R.Madam has read too much into the CNN report. CNN > > > >>mentioned that the speed of light is approximately 300 000 km/s, >they > > >gave > > > >>no other figure, nor did the despatch state how fast the speed of >light > > >is > > > >>slowing down. Until we get more details we can only continue to use >the > > > >>accepted speed of light, which is > > > >> c = 299 792 458 m/s. > > > >>Since 1948 this relationship defines the metre in terms of the >second, > > > > > > > >Was it not in 1983? > > > > > > > > >Quite right, Louis. Thanks for the correctioon. The figure for the >speed > > >of light was adopted in 1975, and that figure was used to define the >metre > > >in 1983. > > >This was obviously one of my bad days. > > > > > > > > > >>which was defined in 1968 as: > > > >>"The second is the duration of 9 192 631 770 periods of the >radiation > > > >>corresponding to the transition between the two hyperfine levels of >the > > > >>ground state of the caesium 133 atom." > > > > > > > >Was it not in 1967? > > > > > > > >Louis > > > > > > > > >The BIPM metric bible says that the latest version of the definition of >the > > >second was adopted by the 13th CGPM, 1967-1968. I did not know which >date > > >to choose, so I wrote 1968. It probably was 1967 because it was >Resolution > > >1 of the meeting. The bible lists 6 other resolutions of the meeting. > > > > > >Joe > > > > > >Joseph B.Reid > > >17 Glebe Road West > > >Toronto M5P 1C8 Tel. 416 486-6071 > > > > > > > > > > _________________________________________________________________ > > MSN Photos is the easiest way to share and print your photos: > > http://photos.msn.com/support/worldwide.aspx > > _________________________________________________________________ Send and receive Hotmail on your mobile device: http://mobile.msn.com
