Paul Dirac Quotes

Actually, I was more or less determined to be a theoretical physicist at the age of thirteen.

As you know, a theory in physics is not useful unless it is able to predict underlined effects which we would otherwise expect.

Schrödinger's wave-mechanics is not a physical theory, but a dodge - and a very good dodge too.

The scientific theorist is not to be envied. For Nature, or more precisely experiment, is an exorable and not very friendly judge of his work. It never says "yes" to a theory. In the most favorable cases it says "Maybe," and in the great majority of cases simply "No." If an experiment agrees with a theory it means for the latter "Maybe," and if it does not agree it means "No." Probably every theory will some day experience its "No" - most theories, soon after conception.

If we are going t stick to this damned quantum-jumping, then I regret that I ever had anything to do with quantum theory.

There are theoretical physicists who imagine, deduce, and guess at new laws, but do not experiment; and then there are experimental physicists who experiment, imagine, deduce, and guess.

Willard Gibbs did for statistical mechanics and for thermodynamics what Laplace did for celestial mechanics and Maxwell did for electrodynamics, namely, made his field a well-nigh finished theoretical structure.

It seems sensible to discard all hope of observing hitherto unobservable quantities, such as the position and period of the electron... Instead it seems more reasonable to try to establish a theoretical quantum mechanics, analogous to classical mechanics, but in which only relations between observable quantities occur.

If someone points out to you that your pet theory of the universe is in disagreement with Maxwell's equations - then so much the worse for Maxwell's equations. If it is found to be contradicted by observation - well, these experimentalists do bungle things sometimes. But if your theory is found to be against the second law of thermodynamics I can give you no hope; there is nothing for it but to collapse in deepest humiliation.

No. I had successfully solved the difficulty of finding a description of the electron which was consistent with both relativity and quantum mechanics. Of course, when you solve one difficulty, other new difficulties arise. You then try to sove them. You can never solve all difficulties at once.

The special theory of relativity owes its origins to Maxwell's equations of the electromagnetic field.

The job of a theoretical physicist is to make mistakes as fast as possible .

Quantum mechanics, that brilliantly successful flagship theory of modern science, is deeply mysterious and hard to understand. Eastern mystics have always been deeply mysterious and hard to understand. Therefore, Eastern mystics must have been talking about quantum theory all along.

Certainly science should continue to see whether we can find evidence for multiverses that might explain why our own universe seems to be so finely tuned.

I had two passions when I was a child. First was to learn about Einstein's theory and help to complete his dream of a unified theory of everything. That's my day job. I work in something called string theory. I'm one of the founders of the subject. We hope to complete Einstein's dream of a theory of everything.

It is almost impossible to have a baseless snobbish opinion of the General Theory of Relativity.

One thing most of us agree on is that the universe exists (people who deny that usually follow some trade other than science), so if some theoretical particle interaction would lead ultimately to the nonexistence of the universe, then you can save a lot of electricity by not trying to demonstrate it.

The TV scientist who mutters sadly, "The experiment is a failure; we have failed to achieve what we had hoped for," is suffering mainly from a bad script writer. An experiment is never a failure solely because it fails to achieve predicted results. An experiment is a failure only when it also fails adequately to test the hypothesis in question, when the data it produces don't prove anything one way or another.

There's far more truth in the Book of Genesis than in the quantum theory.

The mathematics clearly called for a set of underlying elementary objects-at that time we needed three types of them-elementary objects that could be combined three at a time in different ways to make all the heavy particles we knew. ... I needed a name for them and called them quarks, after the taunting cry of the gulls, "Three quarks for Muster mark," from Finnegan's Wake by the Irish writer James Joyce.

Theory said one thing and the experiment said something different, so that was the stimulus that started me going, that there was something there to be explained, which wasn't understood and to try to see why that experiment gave the answer it did, so it was a big opportunity for a young student starting to have actually an experiment which contradicted the theory, so that's was my chance to understand that.

The more experiences and experiments accumulate in the exploration of nature, the more precarious the theories become. But it is not always good to discard them immediately on this account. For every hypothesis which once was sound was useful for thinking of previous phenomena in the proper interrelations and for keeping them in context. We ought to set down contradictory experiences separately, until enough have accumulated to make building a new structure worthwhile.

I have done a terrible thing, I have postulated a particle that cannot be detected.

The basic idea is to shove all fundamental difficulties onto the neutron and to do quantum mechanics in the nucleus.

The mathematical framework of quantum theory has passed countless successful tests and is now universally accepted as a consistent and accurate description of all atomic phenomena. The verbal interpretation, on the other hand - i.e., the metaphysics of quantum theory - is on far less solid ground. In fact, in more than forty years physicists have not been able to provide a clear metaphysical model.