Remember too that academia is in it for the money, not the science. It's very sad. I believe we'd be so much further along in understanding if it weren't for academia and the "scientific" community. I remember some years back when the study of the speed of light was brought into question (my fav topic). Years went by and some scientist in England wanted to disprove it... but he ended up proving it. He was summarily banned by the scientific community. Years later still two Australians tired of hearing about this issue, set out to disprove it too and only ended up proving it - they too were ostracized. Why is this important? Their studies show that all the atoms in the universe are slowing down at the same rate, about 1%/100 years. What does that matter? During the time of Adam and Eve the speed of the atoms (thereby light) was in the neighborhood of 10,000 times faster! It's a fascinating study - if you can find the information
May I ask who were the English and Australians mentioned in this post, and the approximate dates of their work? I enjoy testing my understanding against new facts and viewpoints. There have even been times when I changed or even reversed an opinion based on a cogent discussions.
It has been my impression (and I have read several papers on the subject) that much of the changes in the measured speed of light is, until recently, a measurement of the inherent difficulty in measurement. In antiquity an experiment would go something like (in the example of Galileo's measurement in 1638) one person at night at the top of one hill uncovers a lamp and starts counting or looks at a timepiece. When another person at the top of a hill a known distance away sees the first light, he uncovers another light. When the first person sees the light from the second lamp, he stops counting or looks at his timepiece. The speed of light is then calculated using the elapsed time as the measurement of how long it took a beam to go up and back. Reaction time as well as the crudity of timepieces are, of course the biggest problems. Several means of dealing with this included repeating the test from hills of different length, and attempting to determine how much time was due to human reaction delay, and subtract that from the result. None of these really succeeded in brining experimental error below the magnitude of the measurement.
Other methods included astronomical methods, which were sometimes fascinating, but still the error bounds were greater than the values obtained, for example one involved using the orbital speed of the Earth in such a way that even small errors in the values used created relatively larger errors in the result. Look up James Bradley's measurements.
It wasn't until Fizeau's experiment in the 1860's of a shining light through a toothed wheel onto a mirror a known distance away, and by observing how far the wheel had moved when the light returned that the information outweighed experimental error, and in a way that could be duplicated by interested scientists. Foucault's use of rotating mirrors a few years later further refined the value.
Michelson (who along with Morley failed to find their either wind) further improved on Foucault's design, and his measurements were published by his associates Pease and Pearson after Michelson's death. This value is within 0.006% of the value known today.
Modern interferometry now gives amazing precision (and repeatability by other scientists).
The point here is that if you put the historically held values of the speed of light in a table, and particularly if you pick and choose which experimental results to include, it is fairly easy to apparently show that light is slowing down (or speeding up for that matter), when all you are truly doing is measuring the decrease in experimental error.
As far as being banned from the scientific community, it happens, but less than many who distrust scientists think. We are all human, and scientists will often protect their reputation (and their grants) fiercely. On the other hand a claim of great magnitude requires proof (hopefully reproducible) of similar magnitude. If you try to publish a paper claiming to show the design of a working perpetual motion machine, you wouldn't get anyone to read it
If you want to open up a can of worms (and get nowhere), we can discuss Occam's Razor: How it is most usefully stated, what it means, and how it is to apply it. It is surprising how little Occam's Razor is at deciding between two competing ideas. It doesn't mean that the view that can be understood by the most people (simplest?) is likely to be most correct.