ee5391aa@hydra.unm.edu (Duke McMullan n5gax) (10/30/89)
In article <1989Oct29.224736.2838@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes: >In article <1989Oct29.174631.12960@ux1.cso.uiuc.edu> mcdonald@aries.scs.uiuc.edu (Doug McDonald) writes: >>I have been in the science business for over 20 years and have >>never heard anyone refer to magnetic fields in Tesla - everyone >>uses gauss... >>Sometimes it might appear in a textbook (usually directed at >>freshmen or sophmores - more advanced books use gauss). >The gauss is the older unit, still used a lot, especially in older sources >and by older writers. The Tesla is the correct modern unit; if you look >around, you'll see increasing use of it in most fields. Listen well to Henry, my friends. Picofarads have been in use for lothesemany years, but when I was first getting interested in this stuff (late '50s), the usage was micromicrofarad, usually abrev.d MMFD. Too, microfarads were abrev.d MFD. Those fine days are past (Subhan Allah!). It took several months before I even was able to discover wuthehell MMFD stood for -- Pop'Tronics ran a nice basic article on capacitors. Still, it was MM instead of pico for at least ten more years. Only in the past ten years have nanofarads come into use, and it's still common to see a cap rated in thousands of microfarads rather than millifarads. Consider this one: how many hams and other electronikers do you know who pro- nounce dB dee-bee, and how many of them actually know it means decibel? Then, how many of them have ever heard of a bel? For the real joker, how many of 'em know what a bel is? It's a lot easier (IMHO) to explain bels than decibels. Think again: how often do you see something rated in tens of decibels, rather than bels? WHY? Habit, I suspect, coupled with the natural conservatism that we all possess. This will change. How many people do you know who know the peta- and exa- prefixes, and the femto- and atto- prefixes? (Admittedly not useful to most of us, unless you're measuring the circumference of Pluto's orbit in electronic radii....;^) We all wear blinders of a sort, lacking omniscience...at least I do; maybe you know all. But, with improved communication, and the old (unwilling) making room for the younger, "these, too will pass away." Too much rambling; good night. d I've been to Australia, so now I know what the inside of a kangaroo's pouch feels like. -- Anon. Duke McMullan n5gax nss13429r phon505-255-4642 ee5391aa@hydra.unm.edu
ankleand@mit-caf.MIT.EDU (Andrew Karanicolas) (10/31/89)
In article <851@ariel.unm.edu> ee5391aa@hydra.unm.edu.UUCP (Duke McMullan n5gax) writes: >In article <1989Oct29.224736.2838@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) >writes: (lots of stuff deleted) >Habit, I suspect, coupled with the natural conservatism that we all possess. >This will change. How many people do you know who know the peta- and exa- >prefixes, and the femto- and atto- prefixes? (Admittedly not useful to most >of us, unless you're measuring the circumference of Pluto's orbit in electronic >radii....;^) > In the microelectronics world, thinking in terms of femtofarads is fairly commonplace. For example, in calculations of gate-source capacitances for a minimum feature size MOS device. .
john@frog.UUCP (John Woods) (11/01/89)
In article <851@ariel.unm.edu>, ee5391aa@hydra.unm.edu (Duke McMullan n5gax) writes: > Consider this one: how many hams and other electronikers do you know who pro- > nounce dB dee-bee, and how many of them actually know it means decibel? Now hol' on thar! *I* pronounce it "dee bee", and I *know* that it means one-tenth of a bel. How one pronounces a unit often has more to do with convenience than with knowledge of the underlying unit (just TRY to tell me you've never referred to a "5 puff capacitor" :-). > > Habit, I suspect, coupled with the natural conservatism that we all possess. > This will change. How many people do you know who know the peta- and exa- > prefixes, and the femto- and atto- prefixes? > I do (despite a highly embarrasing article recently in which I interchanged peta and exa...:-). Two habits I do refuse to part with, however, are "mhos" and "cycles [per second]" (especially the former). "Mho"s are not only meaningful, but FUN as well.
fwb@demon.siemens.com (Frederic W. Brehm) (11/03/89)
>In the microelectronics world, thinking in terms of femtofarads is >fairly commonplace. For example, in calculations of gate-source capacitances >for a minimum feature size MOS device. . The microelectronics world does not use SI units everywhere, however. It is commonplace to put (ignore the magnitudes, look at the mish-mash of units) a 5000 Angstrom thick 1 micron wide line on a 2000 square mil die on a 4 inch diameter wafer! This is changing, though. Fred -- Frederic W. Brehm Siemens Corporate Research Princeton, NJ fwb@demon.siemens.com -or- princeton!siemens!demon!fwb
fwb@demon.siemens.com (Frederic W. Brehm) (11/03/89)
In article <2231@frog.UUCP> john@frog.UUCP (John Woods) writes: >... Two habits I do refuse to part with, however, are "mhos" ... >..."Mho"s are not only meaningful, but FUN as well. Horrors! You should use the correct unit (siemens). We use it a lot around here. :-) Fred -- Frederic W. Brehm Siemens Corporate Research Princeton, NJ fwb@demon.siemens.com -or- princeton!siemens!demon!fwb
marc@noe.UUCP (Marc de Groot) (11/03/89)
In article <851@ariel.unm.edu> ee5391aa@hydra.unm.edu.UUCP (Duke McMullan n5gax) writes: >Habit, I suspect, coupled with the natural conservatism that we all possess. >This will change. How many people do you know who know the peta- and exa- What are the values for peta- and exa- ? -- Marc de Groot (KG6KF) These ARE my employer's opinions! Noe Systems, San Francisco UUCP: uunet!hoptoad!noe!marc Internet: marc@kg6kf.AMPR.ORG
pvo3366@sapphire.OCE.ORST.EDU (Paul O'Neill) (11/04/89)
NEW CONVERSIONS from EE Times -- 17 Aug 81 Earl rogers, president of Precision Monolithics, has uncovered the following useful conversion factors. 10^12 microphones = 1 megaphone 10^12 pins = 1 terrapin 10^-12 picolos = 1 pico-boulevard 10^21 picolos = 1 gigolo 10 rations = 1 decoration 10 millipedes = 1 centipede 1 centipede/second = 1 velocipede 3 1/3 tridents = 1 decadent 5 holocausts = 1 Pentecost 10^6 bicycles = 2 megacycles 10^9 micrometers = 1 kilometer = 200 pentameters 10 monologues = 5 dialogues = 1 decalogue 2 x 10^3 millinaries = 4 seminaries (*) = 1 binary 10^-5 dollars = 1 Millicent 1 milli-Helen = the amount of beauty required to launch 1 ship nano-nano = a prefix designating 10^18 (*) The enlightenment generated by a seminary is measured in luminaries. Paul O'Neill pvo@oce.orst.edu Coastal Imaging Lab OSU--Oceanography Corvallis, OR 97331 503-754-3251
johne@hpvcfs1.HP.COM (John Eaton) (11/07/89)
<<<<< < Now, for a unit that is truly bizarre, consider the reciprocal of < capacitance, referred to as "elastance", which is measured in "darafs". < I kid you not. ---------- Well, that makes it consistant with the mho (1/Resistance). John Eaton !hpvcfs1!johne
karn@jupiter..bellcore.com (Phil R. Karn) (11/11/89)
>Only in the past ten years have nanofarads come into use So far the unit seems to be most popular in Europe. Unfortunately, it's still almost unknown in the US. It's so much easier to say "10 nF" (a common enough value) instead of .01uF or 10000 pF. How many people do you know who know the peta- and exa- >prefixes, and the femto- and atto- prefixes? (Admittedly not useful to most >of us, unless you're measuring the circumference of Pluto's orbit in electronic >radii....;^) Some of these larger prefixes are becoming useful when describing the size of digital databases, or the number of bits you can send over a fiber in a day, or the average age of the US ham population. :-) Actually, the differences between cgs and MKS are trivial in comparison to the *real* problem, which is the brain-damaged English system of units. It's a considerable embarassment to me as an American that we're still not metric. I for one would love to take all the money that's currently being wasted on "OSI migration" in the US and put it into going metric. (See? I'm not an American with an NIH syndrome. When the Europeans -- even the French -- come up with an idea that's actually *better* than what we're already using, I'm all in favor of converting.) Phil