The Ten Most Beautiful Experiments
Lives in Santa Fe, New Mexico. Once did experiment on the Colbert Show, with a big coil lighting-up type thang.
Inspiration for book: Einstein deeply impressed by a compass his father showed him at the age of eight.
Johnson started writing about big science. Top quark paper has two pages of co-authors.
A beautiful experiment: pose a question to nature and get a crisp unambiguous reply.
Beauty in the classical sense: logical simplicity of the apparatus. The idea of being the first mind to solve a particular problem.
Another inspiration was to accumulate some neat gadgets.
Newton’s colour experiment
Newton’s colour experiment: Hooke thought he had a theory of colour where light pulses had weak and strong parts, the order of which affected the colour.
Did many of his experiments at the family farm while on retreat during the plague in 1666. Experimented on himself: Stuck blunt needle between eyeball and socket, and stared at the sun.
Noticed that prisms offset different colours differently. Hence set up his experimentum crucis. Not a surprise to see the rainbow, which was a familiar phenomenon, but what Newton noticed is that the spectrum was in oblongs, as the hole in the window shade was circular. So the big surprise was the shape of the colours not the spreading out.
Then adds a second prism and blocks out all but one colour each at a time, and noticed that different colours were “rays differently refrangible”.
Faraday (Ada Lovelace)
By age 53 Faraday had a nervous breakdown and become depressed, possibly poisoned by chemicals he used, and had fallen out with his church. Started getting fan mail (“mash notes”) from Lovelace.
Earlier, Ørsted noticed that electricity influenced a magnetic needle. Faraday as a young man & Davy tried to reproduce his experiment and noticed that he could induce a current magnetically and move a magnet with a current. Also made a transformer with different numbers of coils.
Faraday having come out of his depression decided to do some experiments on polarised light. Notes that with a powerful electromagnet he can affect the polarisation of a light beam.
Albert A. Michelson
Was trying to prove the existence of the lumeniferous ether. Decided he would measure the motion of the earth through the ether. Started off by measuring the speed of light. Galileo had first suggested a method but wouldn’t work on earth (distances not large enough). Fizeau in 1849 bounced light off Montmartre from a suburb with a rotating mirrored wheel. Foucault did the same experiment with a spinning mirror in 1862. Michelson repeated the latter experiment rather more precisely. He wanted to measure the difference in the speed of two light beams to measure the “æther wind” owing to the motion of the earth through the æther. Expected to find interference patterns owing to beams coming back at different speeds, using an interferometer. An extremely delicate experiment, affected by people walking past outside the lab. Tried in Potsdam on granite down to bedrock base to reduce vibrations, and found no interference. At Case University worked with Morley to refine the experiment. Still no result. Michelson grudgingly came to realise that the maximum speed of light was the same under any conditions. Morley never accepted that there wasn’t æther. Michelson even repeated the experiment once more on top of a mountain and finally accepted the constancy of the speed of light.
Questions
Era of beautiful experiments probably over.
Last updated 2008/05/31