Werner Heisenberg Quotes

Now, what that means is that there is fundamental indeterminacy from quantum mechanics, but besides that there are other sources of effective indeterminacy.

Quantum mechanics brought an unexpected fuzziness into physics because of quantum uncertainty, the Heisenberg uncertainty principle.

The uncertainty principle refers to the degree of indeterminateness in the possible present knowledge of the simultaneous values of various quantities with which the quantum theory deals; it does not restrict, for example, the exactness of a position measurement alone or a velocity measurement alone.

If we look at the way the universe behaves, quantum mechanics gives us fundamental, unavoidable indeterminacy, so that alternative histories of the universe can be assigned probability.

It is impossible to trap modern physics into predicting anything with perfect determinism because it deals with probabilities from the outset.

The world is not made up of particles and waves and beams of light with a definite existence. Instead, the world works in a much more exploratory way. It is aware of all the possibilities at once and trying them out all the time. That is a hard thing to picture.

Physics tells us observations can't be predicted absolutely. Rather, there's a range of possible observations each with a different probability.

If we have an atom that is in an excited state and so is going to emit a photon, we cannot say when it will emit the photon. It has a certain amplitude to emit the photon at any time, and we can predict only a probability for emission; we cannot predict the future exactly.

Quantum mechanics brought an unexpected fuzziness into physics because of quantum uncertainty, the Heisenberg uncertainty principle. String theory does so again because a point particle is replaced by a string, which is more spread out.

Spreading out the particle into a string is a step in the direction of making everything we're familiar with fuzzy. You enter a completely new world where things aren't at all what you're used to.

Old Newtonian physics claimed that things have an objective reality separate from our perception of them. Quantum physics, and particularly Heisenberg's Uncertainty Principle, reveal that, as our perception of an object changes, the object itself literally changes.

All kinds of physical considerations become senseless when we try to apply them to distances smaller than 10 -13 centimeter.

In physics the truth is rarely perfectly clear, and that is certainly universally the case in human affairs. Hence, what is not surrounded by uncertainty cannot be the truth.

When we try to observe things that are very small, the act of observation itself will significantly disturb the state we are seeking to measure.

Thus, the more precisely the position is determined, the less precisely the momentum is known, and conversely.

Can quantum mechanics represent the fact that an electron finds itself approximately in a given place and that it moves approximately with a given velocity, and can we make these approximations so close that they do not cause experimental difficulties?

If we ask, for instance, whether the position of the electron remains the same, we must say 'no'; if we ask whether the electron's position changes with time, we must say 'no'; if we ask whether the electron is at rest, we must say 'no'; if we ask whether it is in motion, we must say 'no'.

Newtonian physics runs into problems at the subatomic level. Down there--in the land of hadrons, quarks, and Schrödinger's cat--things gent freaky. The cool rationality of Isaac Newton gives way to the bizarre unpredictability of Lewis Carroll.

The more precise the measurement of position, the more imprecise the measurement of momentum, and vice versa.

While the finish given to our picture of the world by the theory of relativity has already been absorbed into the general scientific consciousness, this has scarcely occurred to the same extent with those aspects of the general problem of knowledge which have been elucidated by the quantum theory.

Among the lesser effects of quantum theory are gaping holes in old ideas about causality.

It is true that in quantum theory we cannot rely on strict causality. But by repeating the experiments many times, we can finally derive from the observations statistical distributions, and by repeating such series of experiments, we can arrive at objective statements concerning these distributions.

We appear to have form, but we are like a whirlpool. We appear to have form, but we are just whirling electrons.

I am not aware of any sensible theory of how classical gravity could interact with quantum matter, and I can't imagine how such a theory might work.

The more you study quantum mechanics, the more crazy and incomprehensible it becomes. You truly do need a Ph.D. in very high level math and science to understand it at a high, high level.