[citation][nom]face-plants[/nom]The only thing I know of that may bring the speed limit of 'c' into question is a recent experiment at an Italian particle accelerator where they appear to have had neutrinos reach a detector several miles away faster than the speed of light. It has not yet been explained in detail or repeated reliably but I'm curious to find out what the story is.[/citation]
They solved that months ago. It was a loose fiber optic cable delaying a measurement, the neutrinos did not exceed the speed of light.
[citation][nom]Old_Fogie_Late_Bloomer[/nom]1) No, because light doesn't travel at c in the atmosphere.[/citation]
Don't be pedantic. Transpose the metaphor into space and the problem re-appears.
2) Seriously, we're talking about a potential speedup of 0.000009%. How would you be able to tell the difference?
The measurement of a speed is totally irrelevant. It is either possible or not possible to exceed the speed of light. The universe doesn't give a shit about the stupid "if a tree falls in the woods" thought experiment. Things happen, whether or not people are around or know about it doesn't matter one iota.
3) Can you, in fact, articulate why light does not add the velocity of its source to its own natural velocity?
Sure thing.
An object moving at relativistic speeds (greater than around 10% of the speed of light, there's no hard cutoff where normal physics stop applying strictly) has an energy equal to its relativistic gamma multiplied by its mass multiplied by the speed of light squared. You'd recognize the bulk of this equation, e=mc^2, though it has an additional factor of y.
Y, the relativistic gamma, is equal to (1 - v^2/c^2)^-0.5.
If you're competent at high school algebra, you'll notice that as v, your velocity, approaches the speed of light, the gamma approaches infinity. Once it reaches the speed of light, the gamma becomes infinity. This means that moving at the speed of light requires infinite energy.
Let me know when you find a source of infinite energy. Even expending the entire universe's energy a trillion trillion trillion times a second for a googolplex of years won't get you to, or past, the speed of light, because while that's a lot of energy, it's still not infinite.