This post should be about how Maxwell discovered the electromagnetic spectrum and then the theory of the Ether and how light speed was thought to be realtive to that and the michaelson Morely experiment
With all it’s vastness and complexity it’s taken a long time for humans to reach the understanding that we have of the universe that we have. This is the story of evolving understanding and how simplicity gives way to incredible truth’s that seems to sit at odds with how we think life should be… and we’ve only just begun our journey of understanding.
Maxwell and Electro Magnetism
In the 1800’s a Scottish physicist called James Clerk Maxwell discovered electromagnetism. Until this time it was a mystery as to what light actually was but when James Clerk Maxwell discovered that electricity and magnetism were somehow one and the same force and by moving one or the other he created electromagnetic waves.

When the speed of these waves was measured he discovered that they traveled at the speed of light (termed as C and is 180,000 miles per second, 300,000 kilometres per second). Electromagnetic waves propagate differently depending on the frequency of cycles per second – measured in hertz.
At the low end of the spectrum there’s radio waves that move to microwaves to infrared and then to visible light and onto the higher frequencies of ultraviolet, x-rays and gamma rays. What this meant was there was now a whole new branch of physics to understand in relation to the universe.
Light Speed Relative to what?
Electromagnetism and this new understanding of light posed a question, it was known that in terms of motion things moved according to the reference of the observer and that these laws could be applied universally – but in what reference should be used to measure the speed of light?
It was considered that the speed of light was determined by the speed of the light source, this was dismissed as this would have done some really strange an obvious things when observing distant astronomical objects.

So it was then decided that in the same way that sound moves through air – light moves through a medium called ‘the ether’. This substance permeated through space as was the medium that light moved through. The hunt was then on for scientists to detect this ether and work out the speed of Earth in relation to it.
There were 2 possibilities – Earth was moving relative to the ether or it wasn’t. If it wasn’t then this fact would send us back to the the Aristotle model of the Earth being a ‘special place’. By astronomical observations of stars at different times of the year it was worked out that we are moving relative to the ether. But then things got complicated…
Michelson Morley and The Ether Experiment
Working out how fast Earth was moving relative to the ether was a huge undertaking in the 1880’s. To come up with an experiment that was sensitive enough to detect the change in the speed of light between Earth and Ether at one time of year and then another they came of with a system that split and re-combined light along 2 paths and using the different phases in light to help them detect the difference.

The whole experiment was set in stone and floated on a mercury as stone is less dense and they took measurements that wouldn’t measure the speed – but would definitely measure the change. They took the measurements and got nothing. No change, the results came back as zero.
To this day the Michelson Morley experiment is known as the most famous failed experiment in science. The questions of at what speed does the Earth move relative to the ether and even by what reference does the light move to still remained and this caused a crisis in science with even the suggestion that the equipment was compressed in the direction of the ether being used to explain the problem
© Simon Farnell 2013 – 2023

Morley tried and folk said ‘That doesn’t work’. It can be said knowing what doesn’t work is a great boon to progress.
Thanks for another insight into our quest for knowledge of the seemingly Intangible.
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Always a pleasure 🙂
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👍
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