Part of my delay in responding to this question was trying to figure out a way to explain the Fine Structure Constant in layterms, and to do so without coming off as rude or dismissive. It's NOT a impertinent question at all, but it's not easy to explain.
Here's a quote by Richard Feynman on the
Fine-Structure Constant:
There is a most profound and beautiful question associated with the observed coupling constant, e - the amplitude for a real electron to emit or absorb a real photon. It is a simple number that has been experimentally determined to be close to 0.08542455. (My physicist friends won't recognize this number, because they like to remember it as the inverse of its square: about 137.03597 with about an uncertainty of about 2 in the last decimal place. It has been a mystery ever since it was discovered more than fifty years ago, and all good theoretical physicists put this number up on their wall and worry about it.) Immediately you would like to know where this number for a coupling comes from: is it related to pi or perhaps to the base of natural logarithms? Nobody knows. It's one of the greatest damn mysteries of physics: a magic number that comes to us with no understanding by man. You might say the "hand of God" wrote that number, and "we don't know how He pushed his pencil." We know what kind of a dance to do experimentally to measure this number very accurately, but we don't know what kind of dance to do on the computer to make this number come out, without putting it in secretly!
The FSC is like Pi, or
Euler's Identity. It's
even deeper that the Speed of Light, and we have
absolutely no idea what it means, except we know it's REALLY IMPORTANT™.
Yes, there is evidence. http://www.phys.unsw.edu.au/astro/research/PWAPR03webb.pdf
This isn't evidence....yet. It's
maybe evidence. First of all, ONLY this team has produced these results, and even they openly are troubled that ALL their data was obtained via one instrument and that opens the door wide for a systemic issue of some kind related to their telescope. They considered this, looked for a problem and couldn't find one, but even they admit that doesn't mean there is certainty in their results.
We need independent confirmation from other teams.Second, other teams HAVE tried to reproduce these results, several times, and they get mixed results. One team says NO, another says YES, several others say MAYBE, yet another team using a totally different approach says HARD NO, cannot be true. Also, I'm NOT AT ALL casting doubts on the team that discovered this data. They are good scientists doing the right thing, we just aren't sure yet if what they found is REAL.
At present there is no firm confirmation of their results, let alone peer-reviewed consensus on their conclusions.
Third, they are measuring the Fine Structure Constant, NOT the speed of light. Now, the speed of light is one of the components of the FSC, but so are other fundamental constants like the Plank Constant. So even if these results are true, further experiments would need to be done to isolate which one(s) are changing within the FSC.
Contrast this with the High-Z Supernova Team that recently discovered that the expansion of the universe was
accelerating. They published results, that frankly were equally dubious at first, but then EVERYONE was able to confirm their findings with multiple independent telescopes and methodologies.
Fourth, this effect isn't predicted or measured in high-energy experiments like the LHC or other accelerators. Even if the universal conditions necessary for this effect no longer exist, we should be able to reproduce these in a lab. Remember, if the speed of light changed, SOMETHING was driving that change: mass density, energy density, something. Such an effect should still be reproduceable, although maybe we haven't been looking for it in the right way....
Finally, it's conceivably plausible that during those
first fractions of a second after the Big Bang that the speed of light changed. We don't expect it to, but if it did THAT'S where it would happen, not millions of years later, and the effects of that could possibly produce results similar to Inflationary models so it may be a second option to Inflation.
creationists think you can just change the definition of constants?
Oh yea, they think it could have taken on any arbitrary value because it's a "fundamental constant", and God "picked" the "right" one. They don't have any idea what they are talking about and it shows.
My question still stands. If light from the first quasars are traveling at a different rate than younger, closer ones...how would that affect our observations? You may treat this as a hypothetical if it helps.
It's a good question. I honestly don't know. Rate is a ratio of distance / time. Did light move a greater distance in the same amount of time, or did it move the same amount in a lesser amount of time. Was "distance" changing or was "time" changing? Is it even possible to distinguish these two from the rate-data alone? (I doubt it)