According to the statement in the next paragraph, this e-mail was not delivered to SITEN. So here it is again, sent the traditional way. It is a reply to Robert, Dennis, Jim and Ambler.
You are not authorized to send mail to the SITEN list from your [email protected] account. You might be authorized to post to the list from another account, or perhaps when using another mail program configured to use a different email address. However, LISTSERV has no way to associate this other account or address with yours. If you need assistance or if you have any questions regarding the policy of the SITEN list, please contact the list owners at [email protected]. ---------- Forwarded message ---------- From: Stanislav Jakuba <[email protected]> To: "James R. Frysinger" <[email protected]> Date: Thu, 26 Aug 2010 17:30:12 -0400 Subject: Re: [SI] SI 10 temperature new comment I agree with Dennis. BIPM is neither infallible nor keen on removing its own contradictions. Several of those concern temperature and Celsius, particularly the thermodynamic temperature. Why the adjective thermodynamic with the temperature in the main table? What are the other temperatures and what are their units? Some justify the adjective on the basis of the existence of the “Celsius temperature” (see SI10). But it is not in any table. Nor would I know what Celsius’ temperature is since he is dead and, worse yet, buried. For decades I have been fighting for the simple statement: “Temperature – its unit is the kelvin in SI, symbol K.” Some (SI10 included) claim that degree Celsius is a derived unit. This cannot be true if one believes the definition of SI derived units and how they are formed. One or the other must be incorrect. Here is the terminology for SI units to help those who may not be sure: base derived derived with special name (and symbol) derived with alternate n. & s. (the alternates are not SI, of course) To illustrate, m/s is derived, N is derived with special name, l or L is an alternate for the dm³. The degree Celsius is neither and has nothing to do with SI by BIPM and SI10 definitions. The degree Celsius is not a derived unit. It can be considered an alternate for the kelvin but only when it means an increment. The fact that the degree Celsius is used almost worldwide, even "used with SI,” does not make it any more SI than the multitude of other traditional units used somewhere or everywhere. Accepting the kelvin as the only unit for its physical quantity, as we do with other SI units, has the practical advantage of eliminating the numerous mistakes caused by converting scales where increments were meant, and vice versa. Some day, an SI knowledgeable tort lawyer in the US will pick up on this and win a case. That’s the US way to implement a change. Or kill it, of course. The whole idea behind SI is coherence. If we do not want to adhere to its principle, why to bather promoting SI? Mr. Ambler is also wrong with his: “Degree Celsius is a SI coherent derived unit with special name and symbol.” And that is unfortunate in his position. I do not mean that he is not repeating what he heard correctly, just that it is wrong. So, Robert, bite the bullet and go for the kelvin. And do not listen to Jim (I am kidding). His arguments are exactly those that would please the BIPM bureaucrat Dennis mentioned. Those points have been occuring endlessly with other units, notably the pascal, delaying its adoption for generations. As the "Fiddler" sings: TRADITION. Let's move on. Stan Jakuba PS: Speaking of the kelvin, some of you will remember Jon Kutz (I do not mean he is dead; just that he did not post anything for a long time). He was selling big, outdoor, circular thermometers graduate in K. I still have it, and all our visitors happily learn how many kelvins it is on our porch. Jon, if you read this – I have buyers for you.
