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Banquet Speech. Listen as you read the banquet speech of Anthony J. Leggett at http://www.nobelprize.org. Do you find his pieces of advice useful?
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Banquet Speech
Listen as you read the banquet speech of Anthony J. Leggett at http: //www. nobelprize. org.
Do you find his pieces of advice useful?
Your Majesties, Your Royal Highnesses, Ladies and Gentlemen.
As a Nobel Laureate one gets asked many questions, some of them very peculiar indeed, but one frequent question that is quite reasonable is: What advice would you give to a student hoping to embark on a career in theoretical physics? Now I should make it clear that my only conceivable qualification, as a mere stripling, for giving this speech on behalf of all three of us physics laureates is that I happen to belong to that fortunate ten percent of the world's population who were born with English as their mother tongue, so I do not know whether my fellow laureates would agree with my answer. But for what it is worth, here it is:
First, if there's something in the conventional wisdom that you don't understand, worry away at it for as long as it takes and don't be deterred by the assurances of your fellow physicists that these questions are well understood.
Secondly, if you find a problem interesting, don't worry too much about whether it has been solved in the existing literature. You will have a lot more fun with it if you don't know, and you will learn a lot, even if what you come up with turns out not to be publishable.
Thirdly, remember that no piece of honestly conducted research is ever wasted, even if it seems so at the time. Put it away in a drawer, and ten, twenty or thirty years down the road, it will come back and help you in ways you never anticipated, and finally, take your teaching every bit as seriously as your research.
As I said, I don't know if my fellow physics laureates would agree with my answer. However, I am sure they will join me in expressing our gratitude, first to the late Alfred Nobel for his generosity in endowing these prizes, secondly to the members of the Nobel Physics Committee of the Royal Swedish Academy of Sciences — having served on several committees for the award of much less prestigious prizes, I can only imagine how much work they have to do and how difficult are the decisions they have to take — and finally to your Majesties and the Nobel Foundation for this sumptuous banquet to-night.
(http: www. nobelprize. org/nobel_prizes/physics/laureates/2003/leggette-speech. html)
Questions
1) Would you like to embark on a career in theoretical physics?
2) What can deter you from studying a certain physics issue?
Unit 4
The Standard Model and the Four Forces. Quantum Chromodynamics
The Nobel Prize in Physics 2004 —
Popular Information
October 5, 2004
The discovery which is awarded this year's Nobel Prize is of decisive importance for our understanding of how the theory of one of Nature's fundamental forces works, the force that ties together the smallest pieces of matter — the quarks. David Gross, David Politzer and Frank Wilczek have through their theoretical contributions made it possible to complete the Standard Model of Particle Physics, the model that describes the smallest objects in Nature and how they interact. At the same time it constitutes an important step in the endeavour to provide a unified description of all the forces of Nature, regardless of the spatial scale — from the tiniest distances within the atomic nucleus to the vast distances of the universe.
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The strong force explained
The strong interaction — often called the colour interaction — is one of Nature’s four basic forces. It acts between the quarks, the constituents that build protons, neutrons and the nuclei. Progress in particle physics or its relevance for our daily life can sometimes appear hard to grasp for anyone without a knowledge of physics. However, when analysing an everyday phenomenon like a coin spinning on a table, its movements are in fact determined by the fundamental forces between the basic building blocks — protons, neutrons, electrons. In fact, about 80% of the coin’s weight is due to movements and processes in the interior of the protons and neutrons — the interaction between quarks. This year’s Nobel Prize is about this interaction, the strong or colour force.
David Gross, David Politzer and Frank Wilczek discovered a property of the strong interaction which explains why quarks may behave almost as free particles only at high energies. The discovery laid the foundation for the theory for the colour interaction (a more complete name is Quantum ChromoDynamics, QCD). The theory has been tested in great detail, in particular during recent years at the European Laboratory for Particle Physics, CERN, in Geneva.
The Standard Model and the four forces of Nature
The first force that must have been evident to humans is gravity. This is the interaction that makes objects fall to the ground but also governs the movements of planets and galaxies. Gravity may seem strong — consider, for example, the large craters formed by comets hitting the earth, or the huge rockets that are required to lift a satellite into space. However, in the microcosmos, among particles like electrons and protons, the force of gravity is extremely weak (fig. 1).
The three forces or interactions, as phycisists prefer to call them, that are applicable to the microcosmos are described by the Standard Model. They are the electromagnetic interaction, the weak interaction and the strong interaction. Through the contributions of several earlier Nobel Laureates the Standard Model has a very strong theoretical standing. This is because it is the only mathematical description which takes into account both Einstein’s theory of relativity and quantum mechanics.
The Standard Model describes quarks, leptons and force-carrying particles. Quarks build, for instance, the protons and neutrons of the atomic nucleus. Electrons that form the outer casing for atoms are leptons and, as far as is known, are not constructed from any smaller constituents. The atoms join up to form molecules, the molecules build up structures and in this way the whole universe can finally be described.
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Fig. 1. The four forces (or interactions) of Nature, their force carrying particles and the phenomena or particles affected by them. The three interactions that govern the microcosmos are all much stronger than gravity and have been
unified through the Standard Model
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