Top 94 Quotes & Sayings by Niels Bohr

Everything we call real is made of things that cannot be regarded as real.

Every description of natural processes must be based on ideas which have been introduced and defined by the classical theory.

Every sentence I utter must be understood not as an affirmation, but as a question.

Technology has advanced more in the last thirty years than in the previous two thousand. The exponential increase in advancement will only continue.

There are some things so serious you have to laugh at them.

Einstein, stop telling God what to do!

A physicist is just an atom's way of looking at itself.

The best weapon of a dictatorship is secrecy, but the best weapon of a democracy should be the weapon of openness.

The opposite of a fact is falsehood, but the opposite of one profound truth may very well be another profound truth.

An expert is a man who has made all the mistakes which can be made, in a narrow field.

No, no, you're not thinking; you're just being logical.

Never express yourself more clearly than you are able to think.

Every great and deep difficulty bears in itself its own solution. It forces us to change our thinking in order to find it.

It is wrong to think that the task of physics is to find out how Nature is. Physics concerns what we say about Nature.

Prediction is very difficult, especially if it's about the future.

Humanity will... be confronted with dangers of unprecedented character unless, in due time, measures can be taken to forestall a disastrous competition in such formidable armaments and to establish an international control of the manufacture and use of the powerful materials.

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

Your theory is crazy, but it's not crazy enough to be true.

When it comes to atoms, language can be used only as in poetry. The poet, too, is not nearly so concerned with describing facts as with creating images.

How wonderful that we have met with a paradox. Now we have some hope of making progress.

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.

It is the hallmark of any deep truth that its negation is also a deep truth.

We depend on our words... Our task is to communicate experience and ideas to others. We must strive continually to extend the scope of our description, but in such a way that our messages do not thereby lose their objective or unambiguous character... We are suspended in language in such a way that we cannot say what is up and what is down. The word "reality" is also a word, a word which we must learn to use correctly.

We are trapped by language to such a degree that every attempt to formulate insight is a play on words.

There are trivial truths and the great truths. The opposite of a trivial truth is plainly false. The opposite of a great truth is also true.

Accuracy and clarity of statement are mutually exclusive.

Nothing exists until it is measured.

There are two sorts of truth: trivialities, where opposites are clearly absurd, and profound truths, recognised by the fact that the opposite is also a profound truth

The meaning of life consists in the fact that it makes no sense to say that life has no meaning.

Truth and clarity are complementary.

Every valuable human being must be a radical and a rebel, for what he must aim at is to make things better than they are.

Isolated material particles are abstractions, their properties being definable and observable only through their interaction with other systems .

When searching for harmony in life one must never forget that in the drama of existence we are ourselves both actors and spectators.

Our task is not to penetrate the essence of things, the meaning of which we do not know anyway, but rather to develop concepts which allow us to talk in a productive way about phenomena in nature

If anybody says he can think about quantum physics without getting giddy, that only shows he has not understood the first thing about them.

If you think you understand it, that only shows that you don't know the first thing about it.

No paradox, no progress.

A physicist visits a colleague and notices a horseshoe hanging on the wall above the entrance. 'Do you really believe that a horseshoe brings luck?' he asks. 'No,' replies the colleague, 'but I've been told that it works even if you don't believe in it.'

In the great drama of existence we are audience and actors at the same time.

There is no hope for any speculation that does not look absurd at first glance.

If we couldn't laugh at ourselves, that would be the end of everything.

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.'

When it comes to atoms, language can be used only as in poetry.

In our description of nature the purpose is not to disclose the real essence of the phenomena but only to track down, so far as it is possible, relations between the manifold aspects of our experience.

Sometimes the child in one behaves a certain way and the rest of oneself follows behind, slowly shaking its head.

The measurement we get when we measure something is not a property of the thing measured.

We are all agreed that your theory is crazy. The question which divides us is whether it is crazy enough to have a chance of being correct. My own feeling is that it is not crazy enough.

It is, indeed, perhaps the greatest prospect of humanistic studies to contribute through an increasing knowledge of the history of cultural development to that gradual removal of prejudices which is the common aim of all science.

The old saying of the two kinds of truth. To the one kind belongs statements so simple and clear that the opposite assertion obviously could not be defended. The other kind, the so-called 'deep truths', are statements in which the opposite also contains deep truth.

When we measure something we are forcing an undetermined, undefined world to assume an experimental value. We are not measuring the world, we are creating it.

A deep truth is a truth so deep that not only is it true but it's exact opposite is also true.

I go into the Upanishads to ask questions.

Physics is the belief that a simple and consistent description of nature is possible.

One must always do what one really cannot.

When it comes to atoms, language can be used only as in poetry. The poet, too, is not nearly so concerned with describing facts as with creating images and establishing mental connections.

It is not enough to be wrong, one must also be polite.

Some subjects are so serious that one can only joke about them.

Opposites are not contradictory but complementary.

If an idea does not appear bizarre, there is no hope for it.

What is that we human beings ultimately depend on? We depend on our words. We are suspended in language. Our task is to communicate experience and ideas to others.