From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-2.9 required=5.0 tests=BAYES_00,FREEMAIL_FROM, MAILING_LIST_MULTI autolearn=unavailable autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII X-Google-Thread: 103376,cc4f25d878383cc X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2001-12-03 08:09:09 PST Path: archiver1.google.com!news2.google.com!news1.google.com!newsfeed.stanford.edu!newsfeeds.belnet.be!news.belnet.be!fr.usenet-edu.net!usenet-edu.net!teaser.fr!enst!enst.fr!not-for-mail From: Wilhelm Spickermann Newsgroups: comp.lang.ada Subject: Re: Another Idea for Ada 20XX Date: Mon, 03 Dec 2001 07:06:00 +0100 Organization: ENST, France Sender: comp.lang.ada-admin@ada.eu.org Message-ID: References: <3C0A5054.E74A82E7@worldnet.att.net> <8GyO7.2671$BS1.330049@news20.bellglobal.com> Reply-To: comp.lang.ada@ada.eu.org NNTP-Posting-Host: marvin.enst.fr Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable X-Trace: avanie.enst.fr 1007395746 42740 137.194.161.2 (3 Dec 2001 16:09:06 GMT) X-Complaints-To: usenet@enst.fr NNTP-Posting-Date: Mon, 3 Dec 2001 16:09:06 +0000 (UTC) To: comp.lang.ada@ada.eu.org Return-Path: In-Reply-To: <8GyO7.2671$BS1.330049@news20.bellglobal.com> X-Mailer: Mulberry/2.1.1 (Linux/x86) Content-Disposition: inline X-Sender: 0211750756-0001@t-dialin.net Errors-To: comp.lang.ada-admin@ada.eu.org X-BeenThere: comp.lang.ada@ada.eu.org X-Mailman-Version: 2.0.6 Precedence: bulk List-Help: List-Post: List-Subscribe: , List-Id: comp.lang.ada mail<->news gateway List-Unsubscribe: , List-Archive: Errors-To: comp.lang.ada-admin@ada.eu.org X-BeenThere: comp.lang.ada@ada.eu.org Xref: archiver1.google.com comp.lang.ada:17346 Date: 2001-12-03T07:06:00+01:00 --On Sunday, December 02, 2001 18:49:24 -0500 Patrick Hohmeyer=20 wrote: > Interesting approach, but at first glance I dont see how > you'll solve the Celsius =3D Kelvin + 273.15 problem. > > This solution seams only to work with units where zero in one > unit equals zero in the other as well. This problem is not a programming problem -- and it has been=20 solved already. Units in physics may not carry any offset information as they=20 are not capable to do this. Doing it would destroy the=20 fundamental concept of equality being a replacement permission:=20 "The outside temperature is 10 degrees celsius, that=B4s 10=20 degrees celsius less than the temperature of my room.". If 10=20 Degrees Celsius would be equal to 283.15 Kelvin, it would have=20 to be possible to replace *both* occurences. Giving: "The=20 outside temperature is 283.15 Kelvin, that=B4s 283.15 Kelvin = less=20 than the temperature of my room." Wow, too hot for me. The solution is (IFAIR it=B4s from the International Conference = on=20 Measurements and Units... in 1972): "The temperature is 10=20 Degrees Celsius" is just a lax abbreviation for: "The=20 celsiustemperature is 10 Kelvin". So it=B4s a different physical = value with the same unit and not the same physical value with a=20 different unit. Note that the conversion between celsius=20 temperature and absolute temperature can now be expressed in a=20 simple equation: TC =3D TA + 273.15 K The same holds for pseudo units like the old german "at=FC" (car = tires) and "Vss"(TV electronics). So it=B4s not a problem of unit conversion, but a problem = occuring=20 in the user interface, where you will have to deal with pseudo=20 units. Wilhelm