Prev: 3D shapes of the Prime Number Sums - 3D_solids.JPG (0/1)
Next: Quantum Gravity 395.3: 2-Time Memory Generalization of Riccati Differential Equations
From: PD on 1 Jun 2010 15:49
On Jun 1, 2:07 pm, "Bill Miller" <kt...(a)yahoo.com> wrote:
> "PD" <thedraperfam...(a)gmail.com> wrote in message
>
> news:5591eae8-4b27-44df-a385-078d51fc6220(a)k31g2000vbu.googlegroups.com...
> On Jun 1, 11:48 am, "Bill Miller" <kt...(a)yahoo.com> wrote:
>
>
>
> > I agree completely.
>
> > How much further ahead would we be if, instead of having to derive
> > products
> > based on *experiments,* we could do so on the basis of *calculations?*
>
> They typically are. But first you have to verify that the calculations
> are reliable, and this is where experiments come in.
>
> We agree here. But when we attempt to apply QM/QED calculations to real
> life, we find numerous instances where the calculations "blow up" or the
> results are nonsensical.

I don't think that's an accurate statement, Bill. QED is the most
exquisitely tested theory on the planet, exceeding every other one to
date. I don't know of any QED result that is nonsensical or blows up
or otherwise conflicts with an experimental measurement.

>
>
>
> > That's especially true if the calculations are based on well-understood
> > principles rather than on equations derived from "curve fitting."
>
> First of all, I'm not sure what kinds of things you think come from
> "curve fitting".
>
> Here are a couple of thoughts to help you: ""Scattering of Light by Free
> Electrons as a Test of Quantum Theory":
> "Is Quantum Theory a System of Epicycles?
> Today, Quantum Mechanics (QM) and Quantum Electrodynamics (QED) have great
> pragmatic success -- small wonder, since they were created, like epicycles,
> by empirical trial-and-error guided by just that requirement.

Again, I don't think that's an accurate statement, Bill.
As for your quoted titles, are those books? If so, who are the authors
and the dates of publication?

>
> "For example, when we advanced from the hydrogen atom to the helium atom, no
> theoretical principle told us whether we should
> represent the two electrons by two wave functions in ordinary 3-d space, or
> one wave function in a 6-d configuration space; only trial-and-error showed
> which choice leads to the right answers.

This is CERTAINLY an incorrect statement.

>
> Then to account for the effects now called 'electron spin', no theoretical
> principle told Goudsmit and Uhlenbeck how this should be incorporated into
> the mathematics. The expedient that finally gave the right answers depended
> on Pauli's knowing about the two-valued representations of the rotation
> group, discovered by Cartan in 1913."

Now, however, you're not talking about ad-hoc fits to data. You're
talking about fortuitous circumstances in the discovery process by
theorists. It's not uncommon for two people who have complementary
insights to get together and provide the synthesis needed to generate
a good model. Exactly the same thing happened with Newton and Hooke
regarding Newton's gravitational law.

>
> If this isn't enough to make the point in a chat session, I suspect I could
> find a few more.
>
> It seems that Jaynes views QM and QED in much the same way that Galileo
> understood epicycles: Emperically built. Mostly gives correct results. Dead
> wrong.
>
> Secondly, it depends on what you mean by "well-understood principles".
> For example, it is known already that the well-understood principle of
> Newtonian mechanics does not work in all cases, and in those cases,
> other principles have to be applied. Same goes for electronics. Same
> goes for a lot of things.
>
> Yes.
>
> Well... Newtonian celestial mechanics, Relativity, and Mendelian genetics
> (mentioned earlier) are physical theories, because their mathematics was
> developed by reasoning out the consequences of clearly stated physical
> principles which constrained the possibilities.
>
> QM/QED concepts simply do not fit this definition.

This is clearly wrong. QED and QM are CERTAINLY based on physical
principles, and the predictions of the theory are constrained by those
physical principles.

I'm afraid you just haven't had a decent exposure to the principles
of, say, QED. There's a lovely and short book by Feynman called QED
that I would recommend to you. There you will find some of the
principles involved.

>
> Also, please look at Jefimenko's "Gravitation and Cogravitation" for an
> example of how one can build on an established (Newton's gravity) concept
> and fill in the blanks based on reasoning rather than curve fitting.
>
> All the best,
>
> Bill Miller

From: PD on 1 Jun 2010 15:55
On Jun 1, 1:08 pm, "Bill Miller" <kt...(a)yahoo.com> wrote:
> "J. Clarke" <jclarke.use...(a)cox.net> wrote in message
>
> news:htp94q129b2(a)news1.newsguy.com...
>
> > Nearly 100 years elapsed between the Navier-Stokes Equations and the
> > Wright Flyer, and nearly 200 before there was enough computing power
> > available to solve them for complex flowfields, so I guess that science
> > "spun its wheels" for most of that time.
>
> > Everything doesn't have immediate, instantaneous practical application,
> > and the stuff that brings about the major changes generally takes a long
> > time to assimilate.
>
> I'm "lumping" J Clarke's comments together with PD's since they both seem to
> have a similar theme:
>
> It took the classicists decades or centuries to go from basic discoveries to
> doing something useful. Therefore we should not be in the least bit
> disturbed if -- in the modern day -- it *also* takes decades with very
> little to show for it.
>
> C'mon folks! During "classical" times, you could count on the fingers of
> your hand the number of folks that were working on (or could even
> understand!) many of the issues that we now acknowledge as "basic science.."
>
> It is only natural that it took decades or centuries.to go from basic
> concepts to useful products.
>
> Ever since the 1930s, there have been thousands (Tens of thousands? Hundreds
> of thousands?) of researchers that have been collectively working on the
> remainder of the EM and gavitational issues. The result Should Have Been a
> complete set of solutions that precisely describe the electrons, protons,
> neutrons and whatever additional bits and pieces go to make up our world. We
> should have closed form solutions for all of this. We should have
> explanations for the strong and weak forces. We should completely
> uinderstand the relationships between EM and Gravitation.
>
> We have none of the above.

Gee, I just don't buy it, Bill. Your argument is that there should be
no problem that should evade complete exploitation in less than a
handful of decades in these modern times.

It doesn't occur to you that the principles of electrodynamics could
be experimented with by a single experimenter in a basement lab using
a couple hundred dollars worth of equipment and devices that at best
only lightly augment our senses. And conversely, some of the laws we
are probing now are WELL outside the reach of our senses and so
require much more collaboration, much more shared, common equipment,
and so on.

>
> I'm reminded of the old joke. A cop finds a drunk on hands and knees
> feverishly searching the ground under a streetlamp. He asks the drunk what
> he's doing. The drunk replies that he's looking for his lost watch.
> "Where," asks the cop, "did you lose it?"
> "Over there." The drunk points to a dark alley.
> "Why aren't you looking for it over there? asked the cop.
> "The light's bettter here," the drunk explained.
>
> Substiute "physicist" for "drunk."
>
> Physicists are looking under the quantum streetlamp. That's not where the
> lost watch is to be found.

Well, Bill, you seem so sure that's the problem. By what basis do you
know this to be the case?

As I asked you in another post, scientists have a way of determining
whether a model is off base. You don't seem to share that method.

>
> All the best,
>
> Bill Miller

From: PD on 1 Jun 2010 15:57
On May 28, 1:38 pm, PD <thedraperfam...(a)gmail.com> wrote:

>
> OK, so here we have another opportunity for clarification. You are
> stating that the outcome of recent science has been what you call
> "silliness".
> Science has a certain methodology for determining what is silly and
> what is not, and this clearly doesn't match your metrics, so we need
> to find out the metric you are using. For what we'll call "science's
> product" understand that what I'm referring to is where you think
> enormous sums of money and effort have been spent on silliness.
> Some possibilities:
> - Science's product is not of any practical value or contemporary
> usefulness, at least relative to the pressing needs of today.
> - Science's product is not understood by you, and therefore it cannot
> be right.
> - Science's product is not believed by you, because it flies in the
> face of what you think is possible in nature, on the basis of your
> experience and common sense, and therefore it cannot be right.
> - Science's product has not been proven in experimental test, and
> therefore it is all just idle speculation.
>
> Which of the above represents your position?
>
>

Bill, you've not answered this question.
From: Timo Nieminen on 1 Jun 2010 17:16
On Jun 2, 2:48 am, "Bill Miller" <kt...(a)yahoo.com> wrote:
> "Timo Nieminen" <t...(a)physics.uq.edu.au> wrote:
>
> But these are certainly not sufficient examples to show that physics
> has been mostly spinning its wheels for a half-century. Example 4
> isn't even science, and it can be argued that 5 isn't physics, so this
> list says very little about physics. The biggest part of physics is
> solid-state/condensed matter/materials physics, with a very strong
> experimental part, with plenty of useful products, commercial
> products, useful results, etc. Optics and photonics (the laser just
> turned 50!) and biophysics as they are now are have grown or re-grown
> almost entirely within that last half-century of supposedly spinning
> wheels.
>
> Thoughtful comments all, Timo. But your exposition also contains an
> explanation for the progress that we *have* made. You said, in part, ..."The
> biggest part of physics is
> solid-state/condensed matter/materials physics,
>
> *with a very strong experimental part, * (Emphasis Mine)
>
> with plenty of useful products, commercial
> products, useful results, etc."
>
> I agree completely.
>
> How much further ahead would we be if, instead of having to derive products
> based on *experiments,* we could do so on the basis of *calculations?*

If we could generate products from calculations alone, yes, we would
be further ahead. But likewise, if we could just wish for products,
we'd also be ahead. We have products that were born in calculation, in
pure theory, but there is often a long road through experiment before
the idea turns into a product. We use such a product in our everyday
research (optical tweezers). This came out of theory and calculation,
c. 1970, but wasn't demonstrated to work until 1986. Now you can buy
it. In this case, the theory and calculation came first.

> That's especially true if the calculations are based on well-understood
> principles rather than on equations derived from "curve fitting."

By and large, they are. In physics, anyway, if not in engineering. The
practical need for answers where theory is insufficient or beyond
current computational capacity makes "curve fitting" still useful. The
testing of scale models in wind tunnels is engineering, not physics.

The "experiment" part in my original response is important. Fields in
physics devoid of experiment don't tend to go anywhere. Theory and
experiment exist in such close symbiosis that both are quite rightly
considered essential parts of a single discipline.

(And, I might add in further response to your original point, of
course we don't have revolutionary great breakthroughs in theory all
the time. If they happen all the time, they're hardly revolutionary.)

--
Timo
From: spudnik on 2 Jun 2010 18:56
the entirety of Schroedinger's joke/cat,
was that it is niether dead nor alive "til we open the box
and look at her," although I only recently read his purported
statement
to that effect.

that is hte whole of the "reification of probability amplitudes"
of the Copenhagenskool of mysticism.
First  |  Prev  | 
Pages: 1 2 3 4 5 6
Prev: 3D shapes of the Prime Number Sums - 3D_solids.JPG (0/1)
Next: Quantum Gravity 395.3: 2-Time Memory Generalization of Riccati Differential Equations