Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!eu.feeder.erje.net!eternal-september.org!feeder.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Martin Gregorie Newsgroups: comp.lang.java.programmer Subject: Re: Autoboxing and Performance ? Date: Thu, 22 Aug 2013 21:19:03 +0000 (UTC) Organization: A noiseless patient Spider Lines: 28 Message-ID: References: <5csRt.197906$jW3.50636@fx23.iad> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Injection-Date: Thu, 22 Aug 2013 21:19:03 +0000 (UTC) Injection-Info: mx05.eternal-september.org; posting-host="e5160e2be48f1ea550cf61512446f525"; logging-data="1808"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19OxfpF4QRftKlEwMTiz8t2leTa39G7xhw=" User-Agent: Pan/0.139 (Sexual Chocolate; GIT bf56508 git://git.gnome.org/pan2) Cancel-Lock: sha1:X0k8WpXvEpCayhFvklaHHMLKVIY= Xref: csiph.com comp.lang.java.programmer:25114 On Thu, 22 Aug 2013 20:19:58 +0000, Stefan Ram wrote: > Moreover, a lenght (in physics) /does not have/ a unit! > As a chemistry graduate I disagree quite strongly with that. Its quite impossible to calculate anything without knowing the units the givens were measured in. I seem to recall a certain NASA Mars probe failing because the units used to measure fuel remaining were unstated. As a result somebody calculated burns wrongly by confusing lbs and kg, causing the probe to run out of fuel and miss Mars entirely. > For example, there is a certain distance from the sun to the Procyon, > what is the unit of that lenght? As a physical value, it has no unit! > Only when one wants to write it down, one has to choose a certain unit > system and number system, and one can choose every unit system one > likes. This is an artefact of our notation, not a property of the > length. > If you don't know the units the measurement was made in, its a meaningless number that can't be used to calculate a valid result any more than you can add "not very far" to "a huge distance" and get a measurable distance. -- martin@ | Martin Gregorie gregorie. | Essex, UK org |