Quotes from Werner Heisenberg

Bohr's influence on the physics and the physicists of our century was stronger than that of anyone else, even than that of Albert Einstein.

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.

The uncertainty relation does not refer to the past; if the velocity of the electron is at first known and the position then exactly measured, the position for times previous to the measurement may be calculated.

I had imagined doing nuclear physics and cosmic ray work in greater style in peace time. To do modern physics in a small way is of no use of all.

The single life is bearable to me only through my work in science, but for the long term, it would be very bad if I had to make do without a very young person next to me.

Not only is the Universe stranger than we think, it is stranger than we can think

The violent reaction on the recent development of modern physics can only be understood when one realises that here the foundations of physics have started moving; and that this motion has caused the feeling that the ground would be cut from science.