Quantum Quotes - page 16
I now imagine a quantum theoretician who may even admit that the quantum-theoretical description refers to ensembles of systems and not to individual systems, but who, nevertheless, clings to the idea that the type of description of the statistical quantum theory will, in its essential features, be retained in the future. He may argue as follows: True, I admit that the quantum-theoretical description is an incomplete description of the individual system. I even admit that a complete theoretical description is, in principle, thinkable. But I consider it proven that the search for such a complete description would be aimless. For the lawfulness of nature is thus constituted that the laws can be completely and suitably formulated within the framework of our incomplete description.
Albert Einstein
The possibility and significance of fractional angular momentum is discussed, and some simple physical realizations of it are mentioned. This leads naturally to consideration of the possibility of fractional quantum statistics, which is seen to be a possibility inherent in the kinematics of 2+1 dimensional quantum mechanics. Both sorts of fractionalization are intimately related to theories, and the classic considerations of Aharonov and Bohm on the significance of the vector potential in quantum mechanics. The meaning and importance of discrete gauge invariance in continuum theories is pointed out. Fractional statistics is shown to have a simple dynamical realization in the dynamics of charge-flux tube composites. Fractional statistics is shown to occur very naturally in the most geometrical quantum field theories in 2+1 dimensions, that is in the nonlinear sigma model and in quantum electrodynamics.
Frank Wilczek
Science teaches us to be very suspicious of grand generalizations...Aristotle had a set theory of the universe, and he didn't get too far. Galileo started with simple things like pendulums and balls sliding down inclined planes, and he got much further. You never find surprises when you think in terms of broad generalities. Both quantum mechanics and relativity grew out of trying to really understand essentially simple things.
Frank Wilczek
The question will be asked and ought to be looked at, what is to be the resource if loans cannot be obtained? There is but one, "Carthago delenda est." Bank paper must be suppressed, and the circulating medium must be restored to the nation to whom it belongs. It is the only fund on which they can rely for loans; it is the only resource which can never fail them, and it is an abundant one for every necessary purpose. Treasury bills, bottomed on taxes, bearing or not bearing interest, as may be found necessary, thrown into circulation will take the place of so much gold and silver, which last, when crowded, will find an efflux into other countries, and thus keep the quantum of medium at its salutary level. Let banks continue if they please, but let them discount for cash alone or for treasury notes.
Thomas Jefferson
Thirty-one years ago [1948], Dick Feynman told me about his "sum over histories" version of quantum mechanics. "The electron does anything it likes," he said. "It just goes in any direction at any speed, forward or backward in time, however it likes, and then you add up the amplitudes and it gives you the wave-function." I said to him, "You're crazy." But he wasn't.
Freeman Dyson
Later attempts sometimes involved outer space...I don't remember them. My wife parodied them all, not unkindly, as "His long green ears quivering, Fimo slipped from the rig.”...there was always something akin to "the rig.” Some unimagined (by me), hence unnamed, element of technology. But already I sensed that even if I had somehow come to know what the rig was, what it was for, it was better not to tell the reader just then. "Javnaker slipped from the quantum universe-splitter that wasn't actually a time machine” would not be good for the reader.
William Gibson
Does life in some way make use of the potentiality for vast quantum superpositions, as would be required for serious quantum computation? How important are the quantum aspects of DNA molecules? Are cellular microtubules performing some essential quantum roles? Are the subtleties of quantum field theory important to biology? Shall we gain needed insights from the study of quantum toy models? Do we really need to move forward to radical new theories of physical reality, as I myself believe, before the more subtle issues of biology - most importantly conscious mentality - can be understood in physical terms? How relevant, indeed, is our present lack of understanding of physics at the quantum/classical boundary? Or is consciousness really "no big deal,” as has sometimes been expressed?
It would be too optimistic to expect to find definitive answers to all these questions, at our present state of knowledge, but there is much scope for healthy debate...
Roger Penrose
It is a fundamental quantum doctrine that a measurement does not, in general, reveal a pre-existing value of the measured property. On the contrary, the outcome of a measurement is brought into being by the act of measurement itself, a joint manifestation of the state of the probed system and the probing apparatus. Precisely how the particular result of an individual measurement is brought into being-Heisenberg's "transition from the possible to the actual"-is inherently unknowable. Only the statistical distribution of many such encounters is a proper matter for scientific inquiry.
David Mermin
I'll be the first to admit that we ultimately don't know what's going on exactly with quantum mechanics, and my personal guess... is that even quantum mechanics is probably an emergent theory, maybe an approximation of... something deeper. Maybe we can get it out of GU somehow, but... I also would guess... the opposite of Roger Penrose... that gravity doesn't really have much to do with this. I think you can... be in a spaceship far away... from any... important gravitating objects and do your little quantum experiments with a Schrödinger-like apparatus and you would get all the same fascinating things happening. So... ignoring gravity... ignoring relativistic effects altogether, you still have this thing people love fighting about. Does the wave function collapse or not, and that's why I'm so interested in this kind of discussion...
Max Tegmark
In conclusion, then, no satisfactory interpretation of quantum mechanics exists today. The questions posed by the confrontation between the Copenhagen interpretation and the hidden variable theorists go to the very foundations of microphysics, but the answers given by hidden variable theorists and Copenhagenists are alike unsatisfactory. Human curiosity will not rest until those questions are answered, but whether they will be answered by conceptual innovations within the framework of the present theory or only within the framework of an as yet unforeseen theory is unknown. The first step toward answering them has been attempted here. It is the modest but essential step of becoming clear on the nature and magnitude of the difficulties.
Hilary Putnam
What we're seeing is a manifestation of the layered nature of our descriptions of reality. At the deepest level we currently know about, the basic notions are things like "spacetime,” "quantum fields,” "equations of motion,” and "interactions.” No causes, whether material, formal, efficient, or final. But there are levels on top of that, where the vocabulary changes.
Sean M. Carroll
I had never met Bell, nor heard him lecture, but in my reading of his scientific papers I have developed a great admiration for him and his work. I have especially admired his attempts to dismantle the orthodox Copenhagen interpretation of quantum theory, written with such tremendous style and obvious enjoyment. Although in this book I have tried to present a balanced account - arguing one way and then another - I hope that I have done justice to Bell's superbly constructed criticisms. The debate over the meaning of quantum theory will certainly be poorer without him.
John Stewart Bell
In our study of applying quantum to cognition we have identified five main aspects that play a fundamental role and that are specific to quantum structures as compared to classical structures. They are (i) contextual in influence (ii) emergence due to superposition, (iii) interference, (iv) entanglement and (v) quantum field theoretic aspects.
Diederik Aerts
Feynman uses Dirac's notation to describe the quantum mechanics of stimulated emission. ... He applies that physics to several physical systems, including dye molecules. ... In this regard, Feynman could have predicted the existence of the tunable laser. Furthermore, Feynman made accessible Dirac's quantum notation via his thought experiments on two-slit interference with electrons.
Richard Feynman
As soon as I arrived at Cornell, I became aware of Dick as the liveliest personality in our department. In many ways he reminded me of Frank Thompson. Dick was no poet and certainly no Communist. But he was like Frank in his loud voice, his quick mind, his intense interest in all kinds of things and people, his crazy jokes, and his disrespect for authority. I had a room in a student dormitory and sometimes around two o'clock in the morning I would wake up to the sound of a strange rhythm pulsating over the silent campus. That was Dick playing his bongo drums. Dick was also a profoundly original scientist. He refused to take anybody's word for anything. This meant that he was forced to rediscover or reinvent for himself almost the whole of physics. It took him five years of concentrated work to reinvent quantum mechanics. He said that he couldn't understand the official version of quantum mechanics that was taught in textbooks, and so he had to begin afresh from the beginning.
Richard Feynman
Architect of quantum theories, brash young group leader on the atomic bomb project, inventor of the ubiquitous Feynman diagram, ebullient bongo player and storyteller, Richard Phillips Feynman was the most brilliant, iconoclastic, and influential physicist of modern times. He took the half-made conceptions of waves and particles in the 1940s and shaped them into tools that ordinary physicists could use and understand. He had a lightning ability to see into the heart of the problems nature posed.
Richard Feynman
