So we have this puzzle or physicists had this puzzle in the 1890s,
what to do with something like the Michelson-Morley result, the null result.
That showed that emotion through the ether could not be
detected even though it should be detectable especially when you compare
to the results of things like stellar aberration.
Where it said clearly it either cannot be dragged.
Which was one possible solution that the Michelson-Morley experiment said.
We're not detecting the motion of the Earth,
through the ether as the earth revolves around the sun.
Maybe it's because the ether in the vicinity of the earth gets bright along
and therefore, we don't feel that ether wind or ether breeze as it were.
Our experiments do not detect it, yet
other results like stellar aberrations said, no the ether can't be right along
by the earth if you're going to get the correct result for things like that.
So it was real puzzle but there were some solutions that were proffered for it.
A British physicist, G F Fitzgerald, really just came up with an idea that,
in the Michelson-Morley experiment, you have light travelling one way,
sort of the headwind-tailwind with either wind supposedly.
And then are going perpendicular where either wind would be crosswind to it.
And there should be a time difference between them because
the headwind tailwind case should take a little bit longer than the crosswind case.
So what he hypothesized was he just had the sort of idea that we're
dealing the ether, the luminiferous ether,
clearly there's some electromagnetic effects perhaps going on.
Matter itself was thought to be composed of perhaps electrical particles
that the electron hadn't actually quite been discovered at this point.
But the idea was in the air that soon the electromagnetic
quantities could explain perhaps the very essence the constitution of matter.
So, if matter itself was electromagnetic in nature that the atoms involved and
so on and so forth.
Perhaps there was an effect as matter,
in this case the Michelson-Morley apparatus traveled through
the ether against it and then it got compressed a little bit.
Just that the very nature sort of drag a fact in the sense that
not they ether drag and we talked about before but
just the compression affect if it's going straight to the ether.
And going cross ways you wouldn't have that compression affect.
So one leg of the Michelson-Morley
apparatus would get compressed just slightly.
And the other leg wouldn't and it'd be just enough to make up that time
difference so that the light beam going this way with the headwind-tailwind case
would actually have slightly less distance to travel than you would expect,
compared to the crosswind case.
And that slight difference in the distance travel would make up for
the fact that it's actually a little bit slower.
So even though that, yes it is slower but the time
travel distance is the same because the distance gets compressed a little bit.
And this was actually became known as the Lorentz contraction because
Fitzgerald published it in the American Journal of Science.
He sent a letter off actually, it wasn't a full publication.
Sent a letter off to the American Journal of Science,
which was very new at the time and hardly anyone ever read.
He wasn't even sure it had been published, really he was on to other things.
A few years after this in the mid 1890s, Lorentz who we've mentioned before,
was developing a full-fledged theory and extending Maxwell's theory and
really puzzling over the Michelson-Morley result, and had a similar idea.
Then he mathematized it and introduced it into his theory.
He later found out that Fitzgerald had actually had this idea a few years before
and had sort of published it.
Lorentz being the kind of person he was gave credit to Fitzgerald and
therefor became known often as the Lorentz-Fitzgerald contraction.