Quotes on Quantum Theory

When asked ... [about] an underlying quantum world, Bohr would answer, 'There is no quantum world. There is only an abstract quantum physical description. It is wrong to think that the task of physics is to find out how nature is. Physics concerns what we can say about Nature.'

Those who are not shocked when they first come across quantum theory cannot possibly have understood it.

And anyone who thinks they can talk about quantum theory without feeling dizzy hasn't yet understood the first thing about it.

Physical concepts are free creations of the human mind, and are not, however it may seem, uniquely determined by the external world.

Quantum theory also tells us that the world is not _x000D_ simply objective; somehow it's something more subtle than that. In some _x000D_ sense it is veiled from us, but it has a structure that we can _x000D_ understand.

All science is either physics or stamp collecting.

The revolution which began with the creation of quantum theory and relativity theory can only be finished with their unification into a single theory that can give us a single, comprehensive picture of nature.

God is subtle but he is not malicious.

The great tragedy of science - the slaying of a beautiful hypothesis by an ugly fact.

If God has made the world a perfect mechanism, He has at least conceded so much to our imperfect intellect that in order to predict little parts of it, we need not solve innumerable differential equations, but can use dice with fair success.

If quantum mechanics hasn't profoundly shocked you, you haven't understood it yet.

Belief in an external world independent of the perceiving subject is the basis of all natural science.

When the province of physical theory was extended to encompass microscopic phenomena through the creation of quantum mechanics, the concept of consciousness came to the fore again. It was not possible to formulate the laws of quantum mechanics in a fully consistent way without reference to the consciousness.

The incomplete knowledge of a system must be an essential part of every formulation in quantum theory. Quantum theoretical laws must be of a statistical kind. To give an example: we know that the radium atom emits alpha-radiation. Quantum theory can give us an indication of the probability that the alpha-particle will leave the nucleus in unit time, but it cannot predict at what precise point in time the emission will occur, for this is uncertain in principle.