Received: by alpheratz.cpm.aca.mmu.ac.uk id UAA18409 (8.6.9/5.3[ref firstname.lastname@example.org] for cpm.aca.mmu.ac.uk from email@example.com); Sun, 17 Mar 2002 20:37:30 GMT Message-ID: <003f01c1cdfa$9212aca0$5e2ffea9@oemcomputer> From: "Philip Jonkers" <firstname.lastname@example.org> To: <email@example.com> References: <NEBBKOADILIOKGDJLPMAGEMOCMAA.firstname.lastname@example.org> Subject: Re: FW: MD Dawkins on quantum/mysticism convergence Date: Sun, 17 Mar 2002 12:26:48 -0900 Organization: Prodigy Internet Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-Mimeole: Produced By Microsoft MimeOLE V6.00.2600.0000 Sender: email@example.com Precedence: bulk Reply-To: firstname.lastname@example.org
> Philip, what a delight to read your message on quantum quantificiation. I
> did not understand it all (what an understatement!) and got a sense of
> you are describing, and the kinds of challenges that the physicists and
> mathematicians were tackling. It also sounds like we haven't seen the end
> attempts to generate a descriptive mathematics that actually does match
> to the observed phenomena. What an intriguing world you describe...
> Many thanks. Thanky you for taking the time to write this up.
Thanks Lawrence, here's another one for you. The slogan 'quantum leap'
dates back all the way to Nils Bohr around 1913 when he introduced the
first quantum treatment of the hydrogenic atom. As you might know the
atom consists of a single electron orbiting a single proton, a hydrogenic
of one electron, Z protons and a bunch of neutrons holding the protons
Until Bohr came along it was a great mystery as to why it was stable when,
according to the
laws of classical physics, the electron should collapse onto the nucleus
as it continuously should lose energy due to Brehm-strahlung (it's like
any electrically charged particle that is subjected to somekind of
field emits radiation this is Brehm-strahlung. An electron orbiting an
charged nucleus is subjected to the Coulomb (accelerating) field caused by
So classically: the hydrogen-atom could not exist (!)and matter in general
also for that matter.
What Bohr did was to allow the angular momentum of the electron only to have
discrete instead of the usual (classical) continuous range of values. This
led to the
famous Bohr model of the hydrogenic atom. After doing the math & physics
wind up with this expression for the allowed range of radii (distances
for the electron:
r = a_0 n*n / Z ,
where r is the radius; n is the quantum number 1,2,3,... -> infinity; a_0 is
(a few Angstrom) and Z is the atomic number of the nuclues (nr of protons).
Also the energy of the tiny little system can be given as:
E = -13.61 Z*Z / (n*n) eV.
So, according to Bohr's model, the electron's observables can only take
discrete values. In other words: the system has been quantized.
Now the relevant question: can the electron change between orbits?
Answer: yes it can, it does so by either absorbing or emitting a photon.
In the former case it gains energy and in the latter it loses it. In doing
it changes its quantum number n. As you can see from the formulas this
corresponds to a dicrete change in radii and energy (and angular momentum).
Finally we have arrived at our destination: the electron has underwent
a quantum jump or leap from n_1 to n_2. It has suddenly and discretely
changed its radius without bothering to make a continuous change.
Or at least, the Bohr model refuses to make any assertions on that part.
So now you also know what is meant by the term: a `quantum leap'.
ps. In my previous post I forgot to credit our great friend: Louis DeBroglie
who had the juvenile audacity to attribute wave-like properties to matter.
Without his heretic thesis we might still be retarded quantum mechanically
So cheers to you to Louis!
> > Lawrence:
> > > > Especially when one remembers that the meaning of the term quantum
> > > > the
> > > > smallest discernible amount. new Age folks sometimes think it
> > means the
> > > > opposite, as in 'a quantum leap.'
> > Wade:
> > > But, AFAIK, that refers to the energy state of electrons, and it _is_
> > > vast leap across a gulf of immense energy, atomically speaking.
> > >
> > > But, some physicist will be coming along shortly to beat my ears with
> > > the facts....
> > Allow me before I hit the sack. Quantum mechanics knows two levels of
> > quantization.
> > In the first some physical quantities, such as energy and angular
> > momentum,
> > are quantized,
> > that is, they are allowed to only take on discrete values represented by
> > socalled
> > quantum numbers. The very first act of quantization was one rather
> > by despair,
> > as a last resort one might say, deployed by Max Planck. So it was that
> > order to solve
> > the great riddle of the ultra-violet catastrophe he decided to allow the
> > radiation due
> > to the black-body system only to take on dicrete energy values.
> > Although he
> > remained
> > repugnant of that dreadfully unholy (read un-classical) decision things
> > fell into places as no classical theory could accomplish before.
> > And look and behold, the quantum era had begun.
> > This purely pragmatical and ad-hoc measure led to the development of the
> > old version of quantum mechanics pioneered by other no less giants such
> > Einstein, Bohr
> > and Sommerfeld. It then took the next generation of physicists such as
> > Heisenberg, Jordan,
> > Born and Schroedinger to substitute the rather ad-hoc mish-mash of
> > (which supposed
> > to be passing for quantum theory) by a more solid and coherent
> > framework by
> > inventing matrix
> > and wave mechanics. Of course, the game wasn't finished until our great
> > friend Paul
> > Dirac came along and casted the whole thing into an even more rigorous
> > mathematically
> > sound theory. Although even then the game wasn't really over and many a
> > mathematician
> > spent a great deal of time proving what Dirac simply had taken
> > for granted (
> > such as the properties
> > of his name-bearing Dirac `function'). After all, Dirac's credo
> > was not too
> > bother too much with
> > the math as long as the physics was right. (After all still, he
> > got a PhD in
> > *applied* mathematics.)
> > In the second quantization matter itself is quantized. Electrons,
> > neutrons and what have
> > you are defined as small packages of energy, mass, momentum, angular
> > momentum
> > and what not. The quantum variant burdened with its description
> > is known as
> > quantum field
> > theory and its existence allows us to interpret experimental
> > results on the
> > bubble chamber
> > for instance, my boss' highly credited invention. Unlike the
> > birth of (real)
> > quantum mechanics in the
> > 20s, to be regarded as a happy time in modern physics as a second rate
> > physicist could
> > do first rate work (wasn't that Felix Bloch who said that?),
> > quantum field theory or better quantum electrodynamics suffered a rather
> > traumatic time of
> > development in the late 30s and 40s due to the discovery of inherent and
> > persistent infinities in the theory.
> > Many physicist saw that as a fair excuse to leave the sinking
> > ship and find
> > pleasure in other
> > areas (such as in biology as Max Delbrueck did and my own boss too
> > presumably).
> > Anyway, I'm dwelling (too much), getting carried away as my sentenced
> > getting too long
> > and fancy and need to get some sleep (no I'm not drunk or
> > intoxicated in any
> > other way).
> > But it was my pleasure and please forgive me if I left out a
> > crucial element
> > or two,
> > Philip.
> > ===============================================================
> > This was distributed via the memetics list associated with the
> > Journal of Memetics - Evolutionary Models of Information Transmission
> > For information about the journal and the list (e.g. unsubscribing)
> > see: http://www.cpm.mmu.ac.uk/jom-emit
> This was distributed via the memetics list associated with the
> Journal of Memetics - Evolutionary Models of Information Transmission
> For information about the journal and the list (e.g. unsubscribing)
> see: http://www.cpm.mmu.ac.uk/jom-emit
This was distributed via the memetics list associated with the
Journal of Memetics - Evolutionary Models of Information Transmission
For information about the journal and the list (e.g. unsubscribing)
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