Reply by Ignacio G.T. May 14, 20122012-05-14
In article <jofjd3$f4l$1@blue-new.rahul.net>, spope33@speedymail.org 
says...
> > josephkk <joseph_barrett@sbcglobal.net> wrote: > > >On Sat, 5 May 2012 05:53:41 +0000 (UTC), spope33@speedymail.org (Steve > > >>Actually I think there is a size lump of silicon, that is sufficiently > >>big that at a given temperature, the number of silicon atoms in that > >>lump varies based on the uncertainty principle. Virtual > >>silicon atoms appear/disappear out of the vacuum all the time. > >>(Trust me, as a EE I know this.) There is no counting the exact number > >>of silicon nucleii in a large lump. > > >This is the first time i have seen virtual particles extended to complete > >nuclei with associated mass rather than the usual boson and lepton virtual > >particles. > > Cool. You heard it from me first. If the lump of silicon is large > enough, this should happen. > > Someone who is actually a physicist can tell you how large. :--) > > > Steve
Wow. And given a whale big enough, do whole cells pop in and out of existence? -- Saludos. Ignacio G.T.
Reply by Steve Pope May 10, 20122012-05-10
josephkk  <joseph_barrett@sbcglobal.net> wrote:

>On Sat, 5 May 2012 05:53:41 +0000 (UTC), spope33@speedymail.org (Steve
>>Actually I think there is a size lump of silicon, that is sufficiently >>big that at a given temperature, the number of silicon atoms in that >>lump varies based on the uncertainty principle. Virtual >>silicon atoms appear/disappear out of the vacuum all the time. >>(Trust me, as a EE I know this.) There is no counting the exact number >>of silicon nucleii in a large lump.
>This is the first time i have seen virtual particles extended to complete >nuclei with associated mass rather than the usual boson and lepton virtual >particles.
Cool. You heard it from me first. If the lump of silicon is large enough, this should happen. Someone who is actually a physicist can tell you how large. :--) Steve
Reply by josephkk May 10, 20122012-05-10
On Sat, 5 May 2012 05:53:41 +0000 (UTC), spope33@speedymail.org (Steve
Pope) wrote:

>Jerry Avins <jya@ieee.org> wrote: > >>On 5/3/2012 5:49 PM, Robert Wessel wrote: > >>> A lump of pure silicon must, by definition, contain an integral number >>> of silicon atoms. > >>Certainly. But its weight need not be a rational fraction of any >>particular weight standard. > >Actually I think there is a size lump of silicon, that is sufficiently >big that at a given temperature, the number of silicon atoms in that >lump varies based on the uncertainty principle. Virtual >silicon atoms appear/disappear out of the vacuum all the time. >(Trust me, as a EE I know this.) There is no counting the exact number >of silicon nucleii in a large lump. > > >Steve
This is the first time i have seen virtual particles extended to complete nuclei with associated mass rather than the usual boson and lepton virtual particles. ?-)
Reply by Mac Decman May 8, 20122012-05-08
On Tue, 01 May 2012 18:16:25 -0500, Tim Wescott <tim@seemywebsite.com>
wrote:

>Instead of doing productive work, I just spent a few enjoyable minutes >with Scilab finding approximations to pi of the form m/n. > >Because I'm posting to a couple of nerd groups, I can be confident that >most of you probably know 22/7 off the tops of your heads. > >What interested me is how spotty things are -- after 22/7, the error >drops for a bit until you get down to 355/113 (which, if you're at an >equal level of nerdiness to me will ring a bell, but not have been >swimming around in your brain to be found). > >But what's _really_ interesting, is that the next better fit isn't found >until you get up to 52163/16604. Then things get steadily better until >you hit 104348/33215 -- at which point the next lowest ratio which >improves anything is 208341/66317, then 312689/99532. At this point I >decided that I would post my answers for your amusement, and get back to >being productive. > >Discrete math is so fun. And these newfangled chips are just destroying >the joy, by making floating point efficient and cheap enough that you >don't need to know little tricks like pi = (almost) 355/113.
Thanks Tim, (I've cross posted just for fun) for bombing out my usenet with this thread. I can't believe this was the one which was better than any troll post! Mark DeArman
Reply by David Brown May 6, 20122012-05-06
On 06/05/12 23:02, Jerry Avins wrote:
> On 5/4/2012 5:59 PM, David Brown wrote: > > ... > >> You are /still/ missing the point - just because you divide two numbers, >> does not make the ratio a /rational/ number. It is only /rational/ if >> the two numbers are integers (or at least rationals). If the numbers are >> unrelated "random" numbers, such as different physical measurements, >> then their ratio will be irrational because there is no fundamental >> common unit of measurement. >> >> It's simple probability. (Actually, it's quite hard probability to do >> this stuff rigorously - but the layman's "it works for finite cases, so >> we extend it to infinite cases" is good enough for now.) There are >> /many/ more irrational numbers than rational ones. In any given range, >> there are only countably infinite rational numbers. But there is 2 to >> the power that many /real/ numbers, so they vastly outweigh the >> rationals. Thus if you pick any two random numbers and divide them, the >> result will be irrational. > > You are almost right. The possibility exists that a pair of irrational > numbers have a rational ratio. Sqrt(8)/sqtrt(2) is an example. >
If the numbers are unrelated, then the probability is /really/ small - it is infinitesimal.
Reply by Jerry Avins May 6, 20122012-05-06
On 5/4/2012 6:45 PM, Jasen Betts wrote:
> On 2012-05-04, Les Cargill<lcargill99@comcast.com> wrote: > >>> Of course, it doesn't make much sense to talk about the irrationality of >>> a measured number, since measurements are by definition limited in >>> precision, and irrationality is a property of the pure number. It may >>> also turn out that it is not constant - perhaps it varies gradually with >>> the expansion of the universe or the strength of surrounding fields. >>> >>> Without any explanation or definition otherwise, however, Avogadro's >>> number is like any other arbitrary number - irrational. >> >> But it's *defined* as a number of atoms. That's the point. If it's an >> indeterminate quantity, it makes no sense to describe it as either >> real nor irrational. > > real numbers are the set of numbers containing all the rational and > irrational numbers, most of real numbers are irrational by a factor of > some infinite amount more than the rational numbers. > > it makes sense to describe any real number that is not known to > be rational as irrational.
Numbers obtained by measurement rather than counting necessarily describe a range. There is an infinite count of numbers within that range. If you must describe measurements in terms of "rational" and "irrational", the correct description is "both". Jerry -- Engineering is the art of making what you want from things you can get. &macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;
Reply by Steve Pope May 6, 20122012-05-06
Jerry Avins  <jya@ieee.org> wrote:

>On 5/4/2012 5:59 PM, David Brown wrote:
>> You are /still/ missing the point - just because you divide two numbers, >> does not make the ratio a /rational/ number. It is only /rational/ if >> the two numbers are integers (or at least rationals). If the numbers are >> unrelated "random" numbers, such as different physical measurements, >> then their ratio will be irrational because there is no fundamental >> common unit of measurement. >> >> It's simple probability. (Actually, it's quite hard probability to do >> this stuff rigorously - but the layman's "it works for finite cases, so >> we extend it to infinite cases" is good enough for now.) There are >> /many/ more irrational numbers than rational ones. In any given range, >> there are only countably infinite rational numbers. But there is 2 to >> the power that many /real/ numbers, so they vastly outweigh the >> rationals. Thus if you pick any two random numbers and divide them, the >> result will be irrational.
>You are almost right. The possibility exists that a pair of irrational >numbers have a rational ratio. Sqrt(8)/sqtrt(2) is an example.
Hence the qualifying term "unrelated". These two number are related. Steve
Reply by Jerry Avins May 6, 20122012-05-06
On 5/4/2012 5:59 PM, David Brown wrote:

   ...

> You are /still/ missing the point - just because you divide two numbers, > does not make the ratio a /rational/ number. It is only /rational/ if > the two numbers are integers (or at least rationals). If the numbers are > unrelated "random" numbers, such as different physical measurements, > then their ratio will be irrational because there is no fundamental > common unit of measurement. > > It's simple probability. (Actually, it's quite hard probability to do > this stuff rigorously - but the layman's "it works for finite cases, so > we extend it to infinite cases" is good enough for now.) There are > /many/ more irrational numbers than rational ones. In any given range, > there are only countably infinite rational numbers. But there is 2 to > the power that many /real/ numbers, so they vastly outweigh the > rationals. Thus if you pick any two random numbers and divide them, the > result will be irrational.
You are almost right. The possibility exists that a pair of irrational numbers have a rational ratio. Sqrt(8)/sqtrt(2) is an example. ... Jerry -- Engineering is the art of making what you want from things you can get. &#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;&#4294967295;
Reply by David Brown May 6, 20122012-05-06
On 05/05/12 00:45, glen herrmannsfeldt wrote:
> In comp.dsp David Brown<david.brown@removethis.hesbynett.no> wrote: > > (snip, someone wrote) >>> Then it's a *fraction*. It's not irrational... I thought I >>> had adequately corrected "integer" to "rational"... in truth, >>> there's a bijective map between them, so... > >> You are /still/ missing the point - just because you divide two numbers, >> does not make the ratio a /rational/ number. It is only /rational/ if >> the two numbers are integers (or at least rationals). If the numbers >> are unrelated "random" numbers, such as different physical measurements, >> then their ratio will be irrational because there is no fundamental >> common unit of measurement. > > In the case of measured quantities, there is no point in saying that > one is irrational. That is, quantities that have an uncertainty.
True.
> > Now, that doesn't mean that physical constants can't be irrational. >
Absolutely. As has been noted already, this discussion is pretty pedantic. All I am really saying is that the theoretical "true" values - that you can never measure, even if they can be said to exist at all - are irrational. In particular, I am saying that you can't call them "rational" nor "integer", unless of course your units are defined to make them rational.
Reply by Fred Abse May 5, 20122012-05-05
On Wed, 02 May 2012 06:23:45 +0100, John Devereux wrote:

> We had a teacher that insisted it was exactly equal!
What did he/she teach? History? drama? civics? languages? phys.ed? -- "For a successful technology, reality must take precedence over public relations, for nature cannot be fooled." (Richard Feynman)