http://books.google.com/books?id=JokgnS1JtmMC
"Relativity and Its Roots" By Banesh Hoffmann
p.92: "There are various remarks to be made about this second
principle. For instance, if it is so obvious, how could it turn out to
be part of a revolution - especially when the first principle is also
a natural one? Moreover, if light consists of particles, as Einstein
had suggested in his paper submitted just thirteen weeks before this
one, the second principle seems absurd: A stone thrown from a speeding
train can do far more damage than one thrown from a train at rest; the
speed of the particle is not independent of the motion of the object
emitting it. And if we take light to consist of particles and assume
that these particles obey Newton's laws, they will conform to
Newtonian relativity and thus automatically account for the null
result of the Michelson-Morley experiment without recourse to
contracting lengths, local time, or Lorentz transformations. Yet, as
we have seen, Einstein resisted the temptation to account for the null
result in terms of particles of light and simple, familiar Newtonian
ideas, and introduced as his second postulate something that was more
or less obvious when thought of in terms of waves in an ether. If it
was so obvious, though, why did he need to state it as a principle?
Because, having taken from the idea of light waves in the ether the
one aspect that he needed, he declared early in his paper, to quote
his own words, that "the introduction of a 'luminiferous ether' will
prove to be superfluous."

http://www.amazon.com/Physical-Relat.../dp/0199275831
Physical Relativity: Space-time Structure from a Dynamical Perspective
Harvey R. Brown
"It is the ultimate irony that the paper which would spell the demise
of the luminiferous ether had as one of its central postulates what
Wolfgang Pauli aptly called the 'true essence of the old aether point
of view'. (...) The most remarkable feature of Einstein's light
postulate is the fact that it seems at first sight antithetical to his
own revolutionary notion of the light quantum. In 1905 it was far from
clear to Einstein what sort of thing the light quantum precisely is,
but it must have seemed closer in nature to a bullet than a wave. The
fact that nonetheless Einstein adopted the LP over an emission theory
of light is testimony to the sureness of his physical intuition in the
midst of blooming, buzzing confusion."

In 1954 Einstein realized that the "ultimate irony" had turned into
ultimate tragedy:

http://www.perimeterinstitute.ca/pdf...09145525ca.pdf
Albert Einstein 1954: "I consider it entirely possible that physics
cannot be based upon the field concept, that is on continuous
structures. Then nothing will remain of my whole castle in the air,
including the theory of gravitation, but also nothing of the rest of
contemporary physics."

If there is doubt as to whether the statement:

"physics cannot be based upon the field concept, that is on continuous
structures"

is equivalent to the statement:

"physics cannot be based on the assumption that the speed of photons,
unlike the speed of bullets, is independent of the speed of the light
source"

here are a few clues:

http://arxiv.org/ftp/physics/papers/0101/0101109.pdf
"The two first articles (January and March) establish clearly a
discontinuous structure of matter and light. The standard look of
Einstein's SR is, on the contrary, essentially based on the continuous
conception of the field."

http://www.pbs.org/wgbh/nova/einstein/genius/
"And then, in June, Einstein completes special relativity, which adds
a twist to the story: Einstein's March paper treated light as
particles, but special relativity sees light as a continuous field of
waves. Alice's Red Queen can accept many impossible things before
breakfast, but it takes a supremely confident mind to do so. Einstein,
age 26, sees light as wave and particle, picking the attribute he
needs to confront each problem in turn. Now that's tough."

http://arxiv.org/PS_cache/astro-ph/p.../0305457v3.pdf
New varying speed of light theories
Joao Magueijo
"In sharp contrast, the constancy of the speed of light has remain
sacred, and the term "heresy" is occasionally used in relation to
"varying speed of light theories". The reason is clear: the constancy
of c, unlike the constancy of G or e, is the pillar of special
relativity and thus of modern physics. Varying c theories are expected
to cause much more structural damage to physics formalism than other
varying constant theories."

http://www.ekkehard-friebe.de/wallace.htm
The Farce of Physics
Bryan Wallace
"Einstein's special relativity theory with his second postulate that
the speed of light in space is constant is the linchpin that holds the
whole range of modern physics theories together. Shatter this
postulate, and modern physics becomes an elaborate farce! (...) The
speed of light is c+v."
[Bryan Wallace wrote "The Farce of Physics" on his deathbed hence some
imperfections in the text!]

Pentcho Valev