Tej Lalvani on Richard Feynman, Radio 4, presenter Matthew Parris, and expert witness David Berman, Professor of Theoretical Physics at Queen Mary University of London.

feynman.jpg

https://www.bbc.co.uk/programmes/b0b0pwgl

Richard Feynman was part of the team that designed the atomic bomb. He was the opposite of a Yes man. Despite being one of the youngest physicists, he was head of calculations in the computation division (remember no computers in those days; calculations were done in the head). If a physicist had a problem at Los Alamos Feynman was the guy you’d ask. He also saved lives. The storage of fission material at Oakridge was at that time likely to lead to meltdown. A problem he recognised and had fixed.

He won the Nobel Prize for Physics but appeared underwhelmed, saying he didn’t believe in such prizes and the real job was in that eureka moment the discovery of verifiably truth.

His friend and fellow physicist Freeman Dyson called Feynman, half buffoon and half genius, only to modify his opinion to full buffoon and full genius. In his book, Surely You’re Joking Mr Feynman, he gave vein to his love of stories and as well as playing the bongo drums, he was a great raconteur. One of the stories here is that Feynman liked to go into topless bars and work on physics problems. He was a trial and error guy. Sometimes it worked and he got the girl, sometimes it didn’t. His first wife, Arlene, had died of TB, and his own mother didn’t want Feynman to marry her in case he contacted the disease.

Feynman was a notable anti-authoritarian. He was asked to solve the problem of what happened when the Space Shuttle Challenger exploded. He was able to show that it was down to the elasticity of a rubber ring.

He was an atheist, but that did not stop him being labelled Jewish. His parents having settled in Queens following the Russian pogroms. He gained a scholarship to MIT, but his application to Columbia was rejected because the science department had filled its quota of Jews. Princeton where he did postgraduate work asked the question if he was Jewish.  In those early years, of course, there wasn’t physics departments. As an undergraduate at MIT he had two papers published and he rewrote the Science syllabus for Cal Tech. He often joked that nobody understood quantum mechanics. The Feynman diagram made that impossibility more likely. Richard Feynman died aged 69. A true polymath and true genius.

 

Fourth Lesson. Particles

quantum

Atoms are the smallest things we can see. Each atom consists of a nucleus orbited by electrons. We’re looking more closely at the nucleus here. Each nucleus consists of protons and neutrons. If we go even smaller protons and neutrons are made up of even smaller units given the name quarks by the American physicist Murray Gell-man. The force that ‘glues’ quarks together inside protons and neutrons is called gluons.

In medieval philosophy an element was thought of as something fundamental that couldn’t be broken further down into anything else. Look at the periodic table. Superimpose on it these building blocks of space and time. Ephemera comes from the Greek and the narrative is linked to a plant the ancients thought lasted only for a day. Elementary particles exist for a much shorter time than that – a fraction of a fraction of a fraction of a fraction of a second. Like quanta in an electromagnetic field they do not have a pebble-like reality and their effect can only be measured in terms of probability. CERN’s Large Hadron Collider in Geneva for example is a loop designed to smash subatomic particles together at increasing speeds. We already knew that elementary particles such as neutrinos existed and swarm throughout the universe, but have little interaction with us, but CERN was able to confirm the existence of the more elusive ‘Higgs bosons’.

This makes it sound like the straightforward world we are used to that of cause and effect. But quantum mechanics has its own laws, which are not laws, but more like whispered suggestions. From the early 1950s to the 1970s physicists such as Richard Feynman and Murray Gell-Mann suggested a set of commonalities and parameters that could be used to experiment with elementary particles called ‘the Standard Model of elementary particles’.  The Higgs Bosons (named after the Scottish physicist Professor Higgs) for example was a thought experiment using quantum mechanics before its existence was confirmed by CERN.

Despite the Standard Model’s success, or perhaps because of its success, it has attracted criticism. It lacks the austere beauty of Einstein’s equations. In comparison it is cobbled together with piecemeal and patched theories without any clear order; an uncertain number of fields; interacting between themselves within certain and uncertain forces; determined by certain constants whose values are unclear; but show a certain (unknown) symmetrical pattern and stirred with a big wooden spoon called the Standard Model.

The Standard Model’s predictions about the unobserved world do work in describing the world as the Higgs Boson shows but it also leads to nonsensical predictions which have to be ignored or counterbalanced; a procedure called ‘renormalisation’.  Paul Dirac, the great architect of quantum mechanics, whom Rovelli places second only to Einstein in the pantheon of twentieth century scientists, concluded ‘we have not yet solved the problem’ of quantum theory.

Quantum theory has more recently been unable to account for what has been termed ‘dark matter’, a large cloud of material observed by astronomers whose gravitation pull deflects light in distant galaxies. Quantum theory is itself in flux, as it always has been.

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Second Lesson: Quanta.

In response to The Daily Post’s writing prompt: “Trick Questions.”

god does not play dice

Carlo Revelli (2015) Seven Brief Lessons on Physics, translated by Simon Carnell and Erica Segree.

If Isaac Newton is the father of physics, Albert Einstein is the mother, but he didn’t love all his children equally. Remember before Einstein, physics was spread out like a dirty nappy between subjects as diverse as Mathematics, Philosophy and the industry leader, Chemistry, in universities and colleges. A fresh-faced Richard Feynman after leaving the Manhattan Project, for example, found himself teaching at Cal Tech. He was the Physics’ department. The atom bomb changed everything, but before the atom bomb, quantum theory (or quantum mechanics) changed everything we know, or think we know, about atoms. Einstein’s theory of gravity, space and time wrapped reality up in a big red bow. Quantum mechanics picked it apart and introduced uncertainty into equations. No one was quite sure how it worked, but quantum mechanics did work. Nowadays, for example, quantum computers exist. Birds navigate from continent to continent by ‘seeing’ the curve of space/time.  Einstein before he died was trying to reconcile the known and the unknown. His theory of everything was championing the god of objectivity in science. And Niels Bohr, whose ongoing dialogue with Einstein enriched science, suggested at a subatomic level the devil of subjectivity played a part. Before he died Bohr had a photograph taken, in the background, a blackboard in his study. The drawing on it is a ‘light filled box’ something Einstein conceived as a thought experiment.

‘Imagine a box filled with light, from which we allow a single photon to escape for an instant…’

Photon from phos/phot ‘light’, but light is both singular and pleural. One cannot be separated from the other.

But that is exactly what Max Planck did. He imagined a hot box. In it an electric field in equilibrium. His genius was suggesting that the energy of this field could be broken down into quanta, packets or lumps of energy. Light, which travelled at a uniform speed through space, in relation to the energy expended in creation, was somehow at a subatomic level, lumpy. It made no sense, but made perfect sense. Einstein confirmed Planck’s hypothesis was correct.

Bohr’s genius was the nowadays clichéd quantum leap of gaining the philosopher’s stone, without quite knowing how it worked. He described how electrons gain and lose the energy of light (that quantum leap) from one oscillating orbit to another and how Mendeleev’s periodic table of how everything remains the same, but is different, could be best understood.

A fellow German physicist, Werner Heisenberg, put a new spin on it by suggesting, at a subatomic level, electrons do not always exist. Objective reality therefore does not exist. An apple, for example, either exist, or it does not. But Heisenberg suggested we did not to follow that strict dichotomy. We could calculate the probability of an electron existing, but only when colliding with something else and making a quantum leap. Before and after, is not measureable, and in the same way, when I’m offline I no longer exist and have no place in the world.

Rovelli puts it very succinctly: ‘It’s as if God had not designed reality with a line that was heavily scored, but just dotted with a faint outline.’

Possibility and probability replace all the old certainties. But like alchemists of old not only were electrons called into being when observed jumping from one random state to another, but the subjective element of looking or measuring could not be teased from cause and effect. I, for example, only exist online when you look at me. I don’t exist otherwise. Or I may exist, but you can’t prove it. And if you try and look at me offline you can no longer see me online. The real and unreal become wrapped around one another. And in observing you become part of the ongoing equation. Look away now. Next up, in the third lesson, ‘The Architecture of the Cosmos’.