Re: Is Intel exceptionally unsuccessful as an architecture designer?

On Sun, 22 Sep 2024 13:10:34 +0000, Tim Rentsch wrote:

Michael S <already5chosen@yahoo.com> writes:
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On Sat, 21 Sep 2024 20:30:40 +0200
David Brown <david.brown@hesbynett.no> wrote:
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Actual physicists know that quantum mechanics is not complete - it is
not a "theory of everything", and does not explain everything.  It
is, like Newtonian gravity and general relativity, a simplification
that gives an accurate model of reality within certain limitations,
and hopefully it will one day be superseded by a new theory that
models reality more accurately and over a wider range of
circumstances.  That is how science works.
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As things stand today, no such better theory has been developed.

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Actually, such theory (QED) was proposed by Paul Dirac back in 1920s and
further developed by many others bright minds.
The trouble with it (according to my not too educated understanding) is
that unlike Schrodinger equation, approximate solutions for QED
equations can't be calculated numerically by means of Green's function.
Because of that QED is rarely used outside of field of high-energy
particles and such.
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But then, I am almost 40 years out of date.  Things could have changed.

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Quantum electrodynamics, aka QED, is a quantum field theory for the
electromagnetic force.  QED accounts for almost everything we can
directly see in the world, not counting gravity.
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The original QED of Dirac, as expressed in the Dirac equation, has a
problem:  according to that formulation, the self-energy of the
electron is infinite.  To address this deficiency, for about 20
years physicists applied a convenient approximation, namely, they
treated the theoretically infinite quantity as zero.  Surprisingly,
that approximation gave results that agreed with all the experiments
that were done up until about the mid 1940s.
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In the late 1940s, Richard Feynman, Julian Schwinger, and Shinichiro
Tomonaga independently developed versions of QED that address the
infinite self-energy problem.  (Tomonaga's work was done somewhat
earlier, but wasn't publicized until later because of the isolation
of Japan during World War II.)  It wasn't at all obvious that the
QED of Feynman and the QED of Schwinger were equivalent.  That they
were equivalent was established and publicized by Freeman Dyson
(while he was a graduate student, no less).
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The problem of the seeminginly infinite self-energy of the electron
was addressed by a technique known as renormalization.  We could say
that renormalization is only an approximation:  it is known to be
mathematically unsound, breaking down after a mere 400 or so decimal
places.  Despite that, QED gives numerical results that are correct
up to the limits of our ability to measure.  A computation done
using QED matched an experimental result to within the tolerance
of the measurement, which was 13 decimal places.  An analogy given
by Feynman is that this is like measuring the distance from LA to
New York to an accuracy of the width of one human hair.
>
QED has implications that are visible in the "normal" world, by
which I mean using ordinary equipment rather than things like
synchrotrons and particle accelerators, and that leaves atoms
intact.  Basically all of chemistry depends on QED and not on
anything more exotic.
>
There are three fundamental forces other than the electromagnetic
force, namely, gravity, the weak force, and the strong force.  The
strong force is what holds together the protons and neutrons in the
nucleus of an atom;  it has to be stronger than the electromagnetic
force so that protons don't just fly away from each other.  The weak
force is related to radioactive decay;  it works only over very
short distances because the carrier particle of the weak force is
fairly massive (about 80 times the mass of a proton IIRC).  For
comparison the carrier particle of the electromagnetic force is the
photon, which is massless;  that means the electromagnetic force
operates over arbitrarily large distances (although of course with a
strength that diminishes as the distance gets larger).
>
The strong force (sometimes called the color force) is peculiar in
that the strong force actually *increases* with distance.  That
happens because the carrier particle of the color force has a color
charge.  For comparison photons are electrically neutral.  It's
because of this property that we never see isolated quarks.
Basically, trying to pull two quarks apart takes so much energy that
new quarks come into existence out of nothing.

It does not come out of nothing, it comes out of the energy being
applied to pull the 2 quarks apart. Once the energy gets that big,
it (the energy) condenses into a pair of quarks which then pair up
to prevent the quarks from being seen in isolation.

                                               Quarks come in three
"colors" (having nothing to do with ordinary color), times three
families of quarks, times two quarks in each family.  The carrier
particle of the strong force is called a gluon, and there are eight
different kinds of gluons.  (It seems like there should be nine, to
allow each of the 3x3 possible combinations of colors, but there are
only eight.)  The corresponding theory to QED for the strong force
is called QCD, for Quantum chromodynamics.
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A joke that I like to tell is because the carrier particle for the
strong force can change a quark from one color to another, rather
than calling it a gluon it should have been called a crayon.
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The field theories for electromagnetism, the strong force, and the
weak force have been unified in the sense that there is a
mathematically consistent framework that accommodates all three.
That unification is only mathematical, by which I mean that there
are no testable physical implications, only a kind of tautological
consistency.  We can see all three field theories through a common
mathematical lens, but that doesn't say anything about how the three
theories interact physically.
>
The gravitational force is much weaker, by 42 orders of magnitude,
than the other three fundamental forces.  The General Theory of
Relativity is not a quantized theory.  There are ideas about how to
unify gravity and the other three fundamental forces, but none of
these "grand unified" theories have any hypotheses that we are able
to test experimentally.  It's unclear how gravity fits in to the
overall picture.

Are you not amazed that everything physicists know about the universe
can be written in 13 equations.

The foregoing represents my best understanding of QED and the other
fundamental forces of physics.  I've done a fair amount of reading
on the subject but I wouldn't claim even to be a physicist, let
alone an expert.