The metric system sucks
in [Math]
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From: Robin on 8 Feb 2010 11:12 On 02/02/2010 23:54, Andrew Usher wrote: > I. Introduction > As English is a common language in internet because most of people use it, metric system will be the common language in science and technology. China, Europe, Russia, South America, Japan speak metric.. Where do you want to sell "inched machines" or inched materials? You won't sell an "inched" car in Europe unless you give free the tools's box together. And I am not sure about the results. The same for transformed materials like bars, rods, etc.. Pull to metric or you'll remain dinosauric.
From: Paul Ciszek on 8 Feb 2010 13:11 In article <205ce359-6482-4ddb-b150-98edf5ba6915(a)q27g2000yqn.googlegroups.com>, Andrew Usher <k_over_hbarc(a)yahoo.com> wrote: >On Feb 7, 8:32�am, nos...(a)nospam.com (Paul Ciszek) wrote: > >> >Well, I guess you can. But just because you can calculate with >> >barbarous units doesn't make them superior - after all, you'd never >> >allow that for English units, would you? >> >> So, how would *you* choose a resistor and a capacitor to produce >> a desired time constant, without using ohms and Farads? > >Oh, I see, the equation T = 1/(2pi RC) works in SI units (and also in >Gaussian units). This doesn't change the principal scientific >objection, though. Do you have any idea what you are talking about? In the equation you just wrote above "T" would have dimensions of reciprocal time, or frequency, regardless of the unit system used. Perhpas you were thinking of a "corner frequency" rather than a time constant? It is very unusual--some would say misleading--to use the letter "T" to designate a frequency. The voltage across a capacitor discharging through a resistor will decrease exponentially according to the equation: V(t) = V(0) * exp(-t/(RC)) Provided R is measured in ohms, C in Farads, and t in seconds. (I suppose V could be measured in anything you like.) While other unit systems are sometimes used in mathematical treatments of fields and radiation, I have never seen any units other than ohms, Farads, Henries, Volts, Amperes, seconds, Hertz, and occasionally Gauss used in circuit design. Nor have I seen components with values denominated in other unit systems for sale anywhere. I would be very interested in seeing any such examples, if you can find any. -- Please reply to: | "Any sufficiently advanced incompetence is pciszek at panix dot com | indistinguishable from malice." Autoreply is disabled |
From: Michael Press on 8 Feb 2010 14:04 In article <hkmiud$dqu$1(a)reader2.panix.com>, nospam(a)nospam.com (Paul Ciszek) wrote: > In article <307d9f52-e674-403a-ad41-29b831fa1d6d(a)r19g2000yqb.googlegroups.com>, > Andrew Usher <k_over_hbarc(a)yahoo.com> wrote: > >On Feb 6, 9:46 am, nos...(a)nospam.com (Paul Ciszek) wrote: > > > >> Sure do. A resistance measured in ohms multiplied by a capacitance > >> measured in Farads gives you an RC time constant in seconds. For > >> the rail gun afficianados, the energy stored in a capacitor measured > >> in Joules is one half the capacitance in Farads times the square of > >> the voltage measured in Volts. Yes, the rail-gun fans I know do > >> talk about energy in Joules. I have even used spot-welders where > >> the intensity of the pulse was given in Joules. > > > >Well, I guess you can. But just because you can calculate with > >barbarous units doesn't make them superior - after all, you'd never > >allow that for English units, would you? > > So, how would *you* choose a resistor and a capacitor to produce > a desired time constant, without using ohms and Farads? Rigged question. Those off the shelf items are labelled in ohms and farads. What is 1 atmosphere in pascal? -- Michael Press
From: Paul Ciszek on 8 Feb 2010 14:33 In article <rubrum-D24F2A.11042308022010(a)news.albasani.net>, Michael Press <rubrum(a)pacbell.net> wrote: >In article <hkmiud$dqu$1(a)reader2.panix.com>, > nospam(a)nospam.com (Paul Ciszek) wrote: > >> In article ><307d9f52-e674-403a-ad41-29b831fa1d6d(a)r19g2000yqb.googlegroups.com>, >> Andrew Usher <k_over_hbarc(a)yahoo.com> wrote: >> >On Feb 6, 9:46 am, nos...(a)nospam.com (Paul Ciszek) wrote: >> > >> >> Sure do. A resistance measured in ohms multiplied by a capacitance >> >> measured in Farads gives you an RC time constant in seconds. For >> >> the rail gun afficianados, the energy stored in a capacitor measured >> >> in Joules is one half the capacitance in Farads times the square of >> >> the voltage measured in Volts. Yes, the rail-gun fans I know do >> >> talk about energy in Joules. I have even used spot-welders where >> >> the intensity of the pulse was given in Joules. >> > >> >Well, I guess you can. But just because you can calculate with >> >barbarous units doesn't make them superior - after all, you'd never >> >allow that for English units, would you? >> >> So, how would *you* choose a resistor and a capacitor to produce >> a desired time constant, without using ohms and Farads? > >Rigged question. Those off the shelf items are labelled >in ohms and farads. By calling them "barbarous units", he is implying that there is somtehing better. I am curious as to what that might be. >What is 1 atmosphere in pascal? Really close to 10^5. Why? -- Please reply to: | "Any sufficiently advanced incompetence is pciszek at panix dot com | indistinguishable from malice." Autoreply is disabled |
From: Bob Myers on 8 Feb 2010 16:09
Andrew Usher wrote: > > SI units make sense? I myself never really understood EM until I saw > the formulae presented in proper units (see Section IIX of my essay). If the units made a difference to your degree of understanding of EM, I would suggest that your understanding isn't all that good. Bob M. |