http://www.edge.org/q2008/q08_5.html
John Baez: "On the one hand we have the Standard Model, which tries to
explain all the forces except gravity, and takes quantum mechanics
into account. On the other hand we have General Relativity, which
tries to explain gravity, and does not take quantum mechanics into
account. Both theories seem to be more or less on the right track --
but until we somehow fit them together, or completely discard one or
both, our picture of the world will be deeply schizophrenic."

http://www.prospect-magazine.co.uk/a...ls.php?id=5538
Paul Davies: "In recent years a few maverick scientists have claimed
that the speed of light might not be constant at all. Shock, horror!
Does this mean the next Great Revolution in Science is just around the
corner?"

http://www.edge.org/3rd_culture/smol...n03_print.html
Lee Smolin: "But there is another possibility. This is that the
principle of relativity is preserved, but Einstein's special theory of
relativity requires modification so as to allow photons to have a
speed that depends on energy. The most shocking thing I have learned
in the last year is that this is a real possibility. A photon can have
an energy-dependent speed without violating the principle of
relativity!"

http://arxiv.org/PS_cache/arxiv/pdf/...705.4507v1.pdf
Joao Magueijo and John W. Moffat: "The question is then: If Lorentz
invariance is broken, what happens to the speed of light? Given that
Lorentz invariance follows from two postulates -- (1) relativity of
observers in inertial frames of reference and (2) constancy of the
speed of light--it is clear that either or both of those principles
must be violated."

http://www.wired.com/wired/archive/1...ingtheory.html
Lee Smolin: "Well, every string theory that's been written down says
the speed of light is universal. But other ideas about quantum gravity
predict the speed of light has actually increased. And an experiment
on the Gamma Ray Large Area Space Telescope, launching next year, will
check this. So I've said, look, if the speed of light isn't universal,
that disconfirms string theory. But the string theorists say they
could probably invent versions of the theory that work either way.
We'd have to change our notion of what science is to accommodate this
proposition. You just can't do science on that basis."

http://cosmo.fis.fc.ul.pt/~crawford/...relativity.pdf
John Stachel: "The idea that a light beam consisted of a stream of
particles had been espoused by Newton and maintained its popularity
into the middle of the 19th century. It was called the "emission
theory" of light, a phrase I shall use...... The usual velocity
addition law is then replaced by a new one, in which the velocity of
light "added" to any other velocity ("added" in a new sense-it would
be better to say "compounded with") does not increase, but stays the
same! The Maxwell-Lorentz equations, when examined with the aid of
this new kinematics, prove to take the same form in every inertial
frame. They are, therefore, quite compatible with the relativity
principle, which demands that the laws of electricity, magnetism and
optics have this property. The presence or absence of an electric or
magnetic field, is then also found to be relative to an inertial
frame, allowing a completely satisfactory relativistic analysis of the
example of the conducting wire loop and magnet in relative motion.
Within six weeks of taking "the step," Einstein later recalled, he had
worked out all of these consequences and submitted the 1905 SRT paper
to Annalen der Physik. This does not imply that Lorentz's equations
are adequate to explain all the features of light, of course. Einstein
already knew they did not always correctly do so-in particular in the
processes of its emission, absorption and its behavior in black body
radiation. Indeed, his new velocity addition law is also compatible
with an emission theory of light, just because the speed of light
compounded with any lesser velocity still yields the same value. If we
model a beam of light as a stream of particles, the two principles can
still be obeyed. A few years later (1909), Einstein first publicly
expressed the view that an adequate future theory of light would have
to be some sort of fusion of the wave and emission theories. This is
an example of how the special theory of relativity functioned as a
theory of principle, limiting but not fixing the choice of a
constructive theory of light."

http://press.princeton.edu/chapters/i6272.html
John Stachel: "Not only is the theory [of relativity] compatible with
an emission theory of radiation, since it implies that the velocity of
light is always the same relative to its source; the theory also
requires that radiation transfer mass between an emitter and an
absorber, reinforcing Einstein's light quantum hypothesis that
radiation manifests a particulate structure under certain
circumstances."

http://ustl1.univ-lille1.fr/culture/...40/pgs/4_5.pdf
Jean Eisenstaedt: "Il n'y a alors aucune raison theorique a ce que la
vitesse de la lumiere ne depende pas de la vitesse de sa source ainsi
que de celle de l'observateur terrestre ; plus clairement encore, il
n'y a pas de raison, dans le cadre de la logique des Principia de
Newton, pour que la lumiere se comporte autrement - quant a sa
trajectoire - qu'une particule materielle. Il n'y a pas non plus de
raison pour que la lumiere ne soit pas sensible a la gravitation.
Bref, pourquoi ne pas appliquer a la lumiere toute la theorie
newtonienne ? C'est en fait ce que font plusieurs astronomes,
opticiens, philosophes de la nature a la fin du XVIIIeme siecle. Les
resultats sont etonnants... et aujourd'hui nouveaux."

Translation from French: "Therefore there is no theoretical reason why
the speed of light should not depend on the speed of the source and
the speed of the terrestrial observer as well; even more clearly,
there is no reason, in the framework of the logic of Newton's
Principia, why light should behave, as far as its trajectory is
concerned, differently from a material particle. Neither is there any
reason why light should not be sensible to gravitation. Briefly, why
don't we apply the whole Newtonian theory to light? In fact, that is
what many astronomers, opticians, philosophers of nature did by the
end of 18th century. The results are surprising....and new nowadays."

Pentcho Valev