Oklo, Gabon ~ this relatively unknown place is tucked away inland on the west coast of Africa, where for nearly the last 40 years it has been revealing more and more data that questions our fundamental concepts of science. What is known (and accepted) so far is that between 2 billion to 1.5 billion earth years ago, deep underground in Oklo a series of natural nuclear reactions took place over several hundred thousand years. According to scientists (and this is a very basic explanation, a proper scientific explanation can be found here) a small amount of water would seep into a vein of Uranium causing an imbalance in the amount of neutrons needed to keep U235 stable causing a chain of reactions to happen until the water was all boiled away. This would repeat as new water seeped in. So far so good.
Here's where it becomes interesting, a pair of scientists (Steve Lamoreaux and Justin Thorgerson of Los Alamos National Laboratories) who had been using the measurements in Oklo to prove that Alpha (the speed of light) was constant with our current measurements published a paper in 2004 showing evidence that Alpha as we know it had decreased by 45 parts in a billion, from 2 billion years ago. This supports what scientist L. Riofrio has been suggesting all along.
Of course, the gloves are off and academics are keen to defend the fine-structure constant which is an incredibly complicated mathematical formula for a fundamental physical constant, which is a dimensionless universal constant. For the scientific community to accept that Alpha is not constant (even within a small fluctuation) would turn fundamental physical science on its head and leave us with more questions and even less answers.
With all of that said, it's fun to wonder about what is making light slow down, if it indeed is doing so. Thoughts about the possiblilty it could be related to the hitherto mysterious dark energy scientists know is out there but can't explain; whether the data the hadron collider collected earlier this year will shed any light (ahem) on the subject or whether it will somehow tie in with the expanding universe theory all remains to be seen.
But what's most fun to wonder about, is if the speed of light is slowing down, does that mean that if we put a flashlight on the front of a spaceship and send it out into the universe will it shine ahead of it...or not?