
Prandtl–Glauert singularity - ColinWright
http://en.wikipedia.org/wiki/Prandtl%E2%80%93Glauert_singularity
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chmike
Could there be a similar singularity with the speed of light ?

~~~
gus_massa
Essentially no (unless a lot of physics changes).

They are very different problems.

 __* Sound Barrier

The air is made of molecules, mostly Nitrogen and Oxygen, lot of them, like
10^23/galon. It’s impossible to keep track of all of them, so you must use
approximations, and the approximate versions are too difficult, so you must
approximate the approximations, until you get a theory that is simple enough
to do the calculations and still it give the correct answer to your problems.

For example, if air is not trapped, then it’s almost incompressible when the
speed is < 0,9 the sound speed (perhaps the approximation is good even for
0.99). I.e. for most of the calculations approximating that air is
incompressible gives almost the correct result, unless you are very close to
the sound speed. Incompressible fluids are lot easier to use in the
calculations. (In particular, an incompressible 2D fluid can be modeled with
complex analysis, it’s a beautiful approximation.) .So you are happier to get
an almost correct result, with a lot less of computations and technical
problems.

From the Wikipedia article:

> _The Prandtl-Glauert transformation is found by linearizing the potential
> equations associated with compressible, inviscid flow._

This formula is a good approximation for slow air flux. If you try to apply
this to almost Mach 1 problems, you void the guaranty.

 __* Light speed Barrier

You can combine Special Relativity, Electromagnetism and Quantum Mechanics
(well you need a Nobel price to do that :) ) and get one of the most precise
Physics Theories. It can be tested with simple systems like a single electron
bouncing against a single electron, so you don’t have to make too many
approximations. (The equipment is very complex and the calculations are awful,
but that’s another kind of approximations.) One of the more precise results is
the magnetic moment of a electron. It depends heavily Special Relativity,
Electromagnetism and Quantum Mechanics. The theoretical result and the
experimental result agree with more than 10 significative figures
[http://en.wikipedia.org/wiki/Anomalous_magnetic_dipole_momen...](http://en.wikipedia.org/wiki/Anomalous_magnetic_dipole_moment).
For all practical propose they are equal. The complete calculation involve
also the week and strong force, but the theories that model them don’t change
Special Relativity.

All the experiments in the LHC use very fast particles and to calculate their
properties you must use a lot of corrections of Special Relativity. So the
theory is already tested for particles with a speed very close to light speed.
It’s very improbable that there will be possible to break the light barrier.

Another problem is that by Special Relativity, if you travel faster than
light, someone with the right speed will see you traveling backward in time,
and you open a Pandora box of paradox. There are some additional problems with
gravity and General Relativity, but they don’t change the main points.

Every Physic Theory be proven wrong by an experiment, so it’s not possible to
say that we will never have to modify Special Relativity to allow faster than
light travel, but it is very improbable.

~~~
chmike
Thatn you very much for your detailed answer. I particularly appreciate your
last sentense that refects true scientific objectivity.

If you are an expert in such topics you may want to have a look at this Space
Time Quantification theory
[1]([http://www.meessen.net/AMeessen/STQ/STQ.pdf](http://www.meessen.net/AMeessen/STQ/STQ.pdf)).
The author has no nobel prize, but this theory propose a new idea of which one
consequence is that speed of light could be bypassed.

The author initially explored the possibility that there could exist a limit
to space and time units. Currently accepted laws assume there is no such
finite limit. He named this finite limit a. Current laws are obtained by
considering a=0. He explored the physics implications if a was different of 0.
He found no contradiction and could even solve some paradox with existing law.
He has a few predictions, some of them is the existence of yet to discover
particles with no charge, that these particles can combine to form havier
neutral particles. Based on these findings he also proposed an original
equivalent of the mendeljev table for elementary particle. It's one of his
assumption that dark matter is made of these neutral particles. He can
suggests tests to check his predictions on LHC data.

