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Article #424

SAVING PHYSICS: TWO POSTULATES

#424
From: Pentcho Valev
Date: Thu, 20 May 2010 05:57
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Physics is dying:

http://www.guardian.co.uk/science/2005/nov/22/schools.g2
"We are nearing the end of the "World Year of Physics", otherwise
known as Einstein Year, as it is the centenary of his annus mirabilis
in which he made three incredible breakthroughs, including special
relativity. In fact, it was 100 years ago yesterday that he published
the most famous equation in the history of physics: E=mc2. But instead
of celebrating, physicists are in mourning after a report showed a
dramatic decline in the number of pupils studying physics at school.
The number taking A-level physics has dropped by 38% over the past 15
years, a catastrophic meltdown that is set to continue over the next
few years. The report warns that a shortage of physics teachers and a
lack of interest from pupils could mean the end of physics in state
schools. Thereafter, physics would be restricted to only those
students who could afford to go to posh schools. Britain was the home
of Isaac Newton, Michael Faraday and Paul Dirac, and Brits made world-
class contributions to understanding gravity, quantum physics and
electromagnetism - and yet the British physicist is now facing
extinction. But so what? Physicists are not as cuddly as pandas, so
who cares if we disappear?"

http://archives.lesechos.fr/archives/2004/LesEchos/19077-80-ECH.htm
"Physicien au CEA, professeur et auteur, Etienne Klein s'inquiète des
relations de plus en plus conflictuelles entre la science et la
société. (...) « Je me demande si nous aurons encore des physiciens
dans trente ou quarante ans », remarque ce touche-à-tout aux multiples
centres d'intérêt : la constitution de la matière, le temps, les
relations entre science et philosophie. (...) Etienne Klein n'est pas
optimiste. Selon lui, il se pourrait bien que l'idée de progrès soit
tout bonnement « en train de mourir sous nos yeux »."

Scientists should try various rescue operations; one of them could
consist in strict adherence to the following postulates:

Postulate 1: (frequency) = (speed of light)/(wavelength)

Postulate 2: The wavelength of light is constant.

Postulate 1 is a universally accepted textbook formula but Postulate 2
needs some justification. Consider this:

http://sampit.geol.sc.edu/Doppler.html
"Moving observer: A man is standing on the beach, watching the tide.
The waves are washing into the shore and over his feet with a constant
frequency and wavelength. However, if he begins walking out into the
ocean, the waves will begin hitting him more frequently, leading him
to perceive that the wavelength of the waves has decreased."

http://www.pitt.edu/~jdnorton/teaching/HPS_0410/chapters/big_bang/index.html
John Norton: "Here's a light wave and an observer. If the observer
were to hurry towards the source of the light, the observer would now
pass wavecrests more frequently than the resting observer. That would
mean that moving observer would find the frequency of the light to
have increased (AND CORRESPONDINGLY FOR THE WAVELENGTH - THE DISTANCE
BETWEEN CRESTS - TO HAVE DECREASED)."

Clearly the decrease in wavelength as a function of the observer's
speed is introduced for idelogical reasons and is physically absurd.
"The observer would now pass wavecrests more frequently" can only mean
"Wavecrests would now have a greater speed relative to the observer".

The reason why the wavelength should vary in a gravitational field is
also purely ideological:

http://www.astronomynotes.com/relativity/s4.htm
"Prediction: light escaping from a large mass should lose energy---the
wavelength must increase since the speed of light is constant."

Authors who claim that the wavelength varies in a gravitational field
while the speed of light remains constant want to be greater
Einsteinians than Einstein: in Einstein's works, the speed of light is
always VARIABLE in a gravitational field:

http://www.physlink.com/Education/AskExperts/ae13.cfm
"So, it is absolutely true that the speed of light is not constant in
a gravitational field [which, by the equivalence principle, applies as
well to accelerating (non-inertial) frames of reference]. If this were
not so, there would be no bending of light by the gravitational field
of stars....Indeed, this is exactly how Einstein did the calculation
in: 'On the Influence of Gravitation on the Propagation of Light,'
Annalen der Physik, 35, 1911. which predated the full formal
development of general relativity by about four years. This paper is
widely available in English. You can find a copy beginning on page 99
of the Dover book 'The Principle of Relativity.' You will find in
section 3 of that paper, Einstein's derivation of the (variable) speed
of light in a gravitational potential, eqn (3). The result is,
c' = c0 ( 1 + V / c^2 )
where V is the gravitational potential relative to the point where the
speed of light c0 is measured."

http://www.mathpages.com/rr/s6-01/6-01.htm
"In geometrical units we define c_0 = 1, so Einstein's 1911 formula
can be written simply as c=1+phi. However, this formula for the speed
of light (not to mention this whole approach to gravity) turned out to
be incorrect, as Einstein realized during the years leading up to 1915
and the completion of the general theory. In fact, the general theory
of relativity doesn't give any equation for the speed of light at a
particular location, because the effect of gravity cannot be
represented by a simple scalar field of c values. Instead, the "speed
of light" at a each point depends on the direction of the light ray
through that point, as well as on the choice of coordinate systems, so
we can't generally talk about the value of c at a given point in a non-
vanishing gravitational field. However, if we consider just radial
light rays near a spherically symmetrical (and non- rotating) mass,
and if we agree to use a specific set of coordinates, namely those in
which the metric coefficients are independent of t, then we can read a
formula analogous to Einstein's 1911 formula directly from the
Schwarzschild metric. (...) In the Newtonian limit the classical
gravitational potential at a distance r from mass m is phi=-m/r, so if
we let c_r = dr/dt denote the radial speed of light in Schwarzschild
coordinates, we have c_r =1+2phi, which corresponds to Einstein's 1911
equation, except that we have a factor of 2 instead of 1 on the
potential term."

http://www.speed-light.info/speed_of_light_variable.htm
"Einstein wrote this paper in 1911 in German (download from:
http://www.physik.uni-augsburg.de/annalen/history/einstein-papers/1911_35_898-908.pdf
). It predated the full formal development of general relativity by
about four years. You can find an English translation of this paper in
the Dover book 'The Principle of Relativity' beginning on page 99; you
will find in section 3 of that paper Einstein's derivation of the
variable speed of light in a gravitational potential, eqn (3). The
result is: c'=c0(1+phi/c^2) where phi is the gravitational potential
relative to the point where the speed of light co is measured......You
can find a more sophisticated derivation later by Einstein (1955) from
the full theory of general relativity in the weak field
approximation....For the 1955 results but not in coordinates see page
93, eqn (6.28): c(r)=[1+2phi(r)/c^2]c. Namely the 1955 approximation
shows a variation in km/sec twice as much as first predicted in
1911."

Pentcho Valev
pvalev@yahoo.com
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From: Pentcho Valev <pvalev@yahoo.com>
Newsgroups: sci.physics.relativity,sci.physics,fr.sci.physique,fr.sci.astrophysique,sci.astro
Subject: SAVING PHYSICS: TWO POSTULATES
Date: Wed, 19 May 2010 22:57:09 -0700 (PDT)
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