How to use this Page

“It’s not quantum mechanics” may often be heard, a remark informing the listener that whatever they are concerned about is nowhere near as difficult, as abstruse, as complicated as quantum mechanics. Indeed to non-physicists or non-mathematicians quantum mechanics must seem virtually impossible to appreciate – pages of incomprehensible algebra buttressed by obscure or frankly paradoxical “explanations”.

The post Quantum mechanics – a new lease of life appeared first on OUPblog.

Add a Comment

Welcome to Theoretical Thursday!

Today I start a new journey of expoloration and learning.  I will endeavor to learn Theoretical Physics. For as long as I can remember I have loved science – the idea that things are discoverable and understandable largely just by being observant. The life cycle of an insect, the growth of mold on bread, the magic of a healing cut, etc. And in physics class - A ball in a wagon is set in motion when the wagon is pulled. When the wagon stops, the ball keeps moving… etc. I get that. After all, I was the girl who scored the highest in all things mechanical on some Junior High assessment test (you had to follow the cogs and wheels of a machine and draw the direction of movement for each.)

But then I hit a road block – theoretical explorations where things like quirks, quarks and the Higgs-Boson particle are spoken about as if they too were sitting in a wagon. As I type this sentence, I realize that my ignorance may be showing and these things are real and observable and I just haven’t understood the conversation. And that is the impetus for this experiment – I want to understand the conversation. I want to understand how very smart men and women can earn a living by making stuff up. At least that is what it seems to me, right now, in my theoretically-challenged brain.

So, who better to teach me Theoretical Physics than the great man himself – Albert Einstein. And I just happen to have his book – RELATIVITY: The Special and the General Theory, A Clear Explanation That Anyone Can Understand. (Wanna bet?) Even Einstein appears to have misgivings as he peers at me with raised eyebrows from the photo on the cover. He holds his hands in pre-wringing motion as if to say, “This job may be harder than I thought.” And I think he may be right.

This book, written in MCMLXI, includes a preface. “The present book is intended, as far as possible, to give an exact insight into the theory of Relativity to those readers who, from a general scientific and philosophical point of view, are interested in the theory, but who are not conversant with the mathematical apparatus of theoretical physics.” I fit that bill – I am interested. And I am not conversant. So far so good.

His next sentence (Don’t worry, I’m not going to go through the whole book sentence by sentence. I think.) presumes I have an education of a standard “corresponding to that of a university matriculation examination.” I have a Masters in Anthropology, but that probably isn’t what he meant. I suspect that exams in MCMLXI might have been more rigorous than they were when I graduated, but I can’t be sure, so I press on.

The book also presumes, “…a fair amount of patience and force of will on the part of the reader.” Hmmm. Might have a problem there. I didn’t have much force of will last night when I ate 4 bowls of popcorn and a couple glasses of wine. (Note: it was “Smart Popcorn”) However, Albert promises that he has written the book in a ‘step-motherly-fashion” (and I’m hoping that doesn’t mean evil Cinderella’s step mother) and he hopes the book may bring someone “a few hours of suggestive thought!” (Albert, you dog! I don’t know about a few hours worth, but I like a suggestive thought now and then.)

That preface was written in December 1916. The edition I have is the 15th edition and on June 9th, 1952 (8 years before I was born) he wrote a short note about the addition of a 5th appendix about the “problem of space in general and on t

Add a Comment

Tweet

The realm of theoretical physics is teeming with abstract and beautiful concepts, and the process of bringing them into existence, and then explaining them, demands profound creativity according to Giovanni Vignale, author of The Beautiful Invisible: Creativity, imagination, and theoretical physics. In the excerpt below Vignale discusses the beginnings of theoretical physics and the abstract.

Physics, most of us would agree, is the basic science of nature. Its purpose is to discover the laws of the natural world. Do such laws exist? Well, the success of physics at identifying some of them proves, in retrospect, that they do exist. Or, at least, it proves that there are Laws of Physics, which we can safely assume to be Laws of Nature.

Granted, it may be difficult to discern this lofty purpose when all one hears in an introductory course is about flying projectiles and swinging pendulums, strings under tension and beams in equilibrium. But at the beginning of the enterprise there were some truly fundamental questions such as: the nature of matter, the character of the forces that bind it together, the origin of order, the fate of the universe. For centuries humankind had been puzzling over these questions, coming up with metaphysical and fantastic answers. And it stumbled, and it stumbled, until one day—and here I quote the great Austrian writer and ironist, Robert Musil:

. . . it did what every sensible child does after trying to walk too soon; it sat down on the ground, contacting the earth with a most dependable if not very noble part of its anatomy, in short, that part on which one sits. The amazing thing is that the earth showed itself uncommonly receptive, and ever since that moment of contact has allowed men to entice inventions, conveniences, and discoveries out of it in quantities bordering on the miraculous.

This was the beginning of physics and, actually, of all science: an orgy of matter-of-factness after centuries of theology. Careful and systematic observation of reality, coupled with quantitative analysis of data and an egregious indifference to theories that could not be tested by experiment became the hallmark of every serious investigation into the nature of things.

But even as they were busy observing and experimenting, the pioneers of physics did not fail to notice a peculiar feature of their discipline. Namely, they realized that the laws of nature were best expressed in an abstract mathematical language—a language of triangles and circles and limits—which, at first sight, stood almost at odds with the touted matter-of-factness of experimental science. As time went by, it became clear that mathematics was much more than a computational tool: it had a life of its own. Things could be discovered by mathematics. John Adams and, independently, Urbain Le Ferrier, using Newton’s theory of gravity, computed the orbit of Uranus and found that it deviated from the observed one. Rather than giving up, they did another calculation showing that the orbit of Uranus could be explained if there were another planet pulling on Uranus according to Newton’s law of gravity. Such a planet had never been seen, but Adams and Le Ferrier told the astronomers where to look for it. And, lo and behold, the planet—Neptune—was there, waiting to be discovered. That was in 1846.

Even this great achievement pales in comparison with things that happened later. In the 1860s, James Clerk Maxwell trusted mathematics—and not just the results of a calculation, but the abstract structure of a set of equations—to predict the existence of electromagnetic waves. And electromagnetic waves (of which visible light is an example) were controllably produced in the lab shortly afterwards.

In the 1870s Ludwig

Add a Comment

Tweet

By Frank Close

Ray Davis was the first person to look into the heart of a star. He did so by capturing neutrinos, ghostly particles that are produced in the centre of the Sun and stream out across space. As you read this, billions of them are hurtling through your eyeballs at almost the speed of light, unseen.

Neutrinos are as near to nothing as anything we know, and so elusive that they are almost invisible. When Davis began looking for solar neutrinos in 1960, many thought that he was attempting the impossible. It nearly turned out to be: 40 years would pass before he was proved right, leading to his Nobel Prize for physics in 2002, aged 87.

In June 2006, I was invited by The Guardian newspaper to write his obituary. An obituary necessarily focuses on the one person, but the saga of the solar neutrinos touched the lives of several others, scientists who devoted their entire careers chasing the elusive quarry, only to miss out on the Nobel Prize by virtue of irony, chance, or, tragically, by having already died.

Of them all, the most tragic perhaps is the genius Bruno Pontecorvo.

Pontecorvo was a remarkable scientist and a communist, working at Harwell after the war. When his Harwell colleague Klaus Fuchs was exposed as an atom spy in 1950, Pontecorvo immediately fled to the USSR. This single act probably killed his chances of Nobel Prizes.

In the following years, Pontecorvo developed a number of ideas that could have won him one or more Nobels. But his papers were published in Russian, and were unknown in the West until their English translations appeared up to two years later. By this time others in the USA had come up with the same ideas, later winning the Nobel Prize themselves.

Amongst his ideas, one involved an experiment which Soviet facilities could not perform. But most ironic were Pontecorvo’s insights about neutrinos.

Ray Davis had detected solar neutrinos – but not enough of them. For years, many of us involved in this area of research thought Davis’ experiment must have been at fault. But Pontecorvo had another theory which indicated that like chameleons, neutrinos changed their form en route across space from the Sun to Earth. And he was right. It took many years to prove it, but by 2000 the whole saga was completed. Davis duly won his Nobel Prize, but so many years had elapsed that Pontecorvo by then was dead.

So although my piece for The Guardian began as the life story of Ray Davis, Pontecorvo was there behind the scenes to such an extent that it became his story also. It is also the story of John Bahcall, Davis’ lifelong collaborator, who, to the surprise of many, was not included in the Nobel award.

The lives of these three great scientists were testimony to what science is all about: as Edison put it, genius is 1% inspiration and 99% perspiration.

A final sobering thought to put our human endeavors in context: those neutrinos that passed through you when you started reading this article are by now well on their way to Mars.

Frank Close OBE is Professor of Physics at Oxford Univeristy and a Fellow of Exeter College.  He is formerly Head of the Theoretical Physics Division at the Rutherford Appleton Laboratory, and Head of Communications and Public Education at CERN. He has written several books including The Void, Antimatter, 0 Comments on Hunting the Neutrino as of 1/1/1900