1. “Prediction is very difficult, especially if it’s about the future.” – Niels Bohr
2. “There are some things so serious that you have to laugh at them.” – Niels Bohr
3. “The best weapon of a dictatorship is secrecy, but the best weapon of a democracy should be the weapon of openness.” – Niels Bohr
4. “A physicist is just an atom’s way of looking at itself.” – Niels Bohr
5. “Sometimes the child in one behaves a certain way and the rest of oneself follows behind, slowly shaking its head.” – Niels Bohr
6. “Accuracy and clarity of statement are mutually exclusive.” – Niels Bohr
7. “The meaning of life consists in the fact that it makes no sense to say that life has no meaning.” – Niels Bohr
8. “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.” – Niels Bohr
9. “If anybody says he can think about quantum physics without getting giddy, that only shows he has not understood the first thing about them.” – Niels Bohr
10. “Prediction is very difficult, especially about the future.” – Niels Bohr
11. “Isolated material particles are abstractions, their properties being definable and observable only through their interaction with other systems .” – Niels Bohr
12. “Everything we call real is made of things that cannot be regarded as real. If quantum mechanics hasn’t profoundly shocked you, you haven’t understood it yet.” – Niels Bohr
13. “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.” – Niels Bohr
14. “When it comes to atoms, language can be used only as in poetry.” – Niels Bohr
15. “The opposite of a fact is falsehood, but the opposite of one profound truth may very well be another profound truth.” – Niels Bohr
16. “How wonderful that we have met with a paradox. Now we have some hope of making progress.” – Niels Bohr
17. “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.” – Niels Bohr
18. “If an idea does not appear bizarre, there is no hope for it.” – Niels Bohr
19. “Nothing exists until it is measured.” – Niels Bohr
20. “The opposite of every great idea is another great idea.” – Niels Bohr
21. “It is the hallmark of any deep truth that its negation is also a deep truth.” – Niels Bohr
22. “If we couldn’t laugh at ourselves, that would be the end of everything.” – Niels Bohr
23. “The measurement we get when we measure something is not a property of the thing measured.” – Niels Bohr
24. “A deep truth is a truth so deep that not only is it true but it’s exact opposite is also true.” – Niels Bohr
25. “It is very difficult to make an accurate prediction, especially about the future.” – Niels Bohr
26. “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.” – Niels Bohr
27. “One must always do what one really cannot.” – Niels Bohr
28. “Your theory is crazy, but it’s not crazy enough to be true.” – Niels Bohr
29. “No paradox, no progress.” – Niels Bohr
30. “If you aren’t confused by quantum mechanics, you haven’t really understood it.” – Niels Bohr
31. “I go into the Upanishads to ask questions.” – Niels Bohr
32. “Those who are not shocked when they first come across quantum theory cannot possibly have understood it.” – Niels Bohr
33. “Never express yourself more clearly than you are able to think.” – Niels Bohr
34. “Some subjects are so serious that one can only joke about them.” – Niels Bohr
35. “It is wrong to think that the task of physics is to find out how Nature is. Physics concerns what we say about Nature.” – Niels Bohr
36. “Every great and deep difficulty bears in itself its own solution. It forces us to change our thinking in order to find it.” – Niels Bohr
37. “When searching for harmony in life one must never forget that in the drama of existence we are ourselves both actors and spectators.” – Niels Bohr
38. “Oh what idiots we have all been, this is just as it must be” – Niels Bohr
39. “Truth and clarity are complementary.” – Niels Bohr
40. “Physics is not about how the world is, it is about what we can say about the world” – Niels Bohr
41. “It is not enough to be wrong, one must also be polite.” – Niels Bohr
42. “No, no, you’re not thinking; you’re just being logical.” – Niels Bohr
43. “Stop telling God what to do with his dice.” – Niels Bohr
44. “We all know your idea is crazy. The question is whether it is crazy enough.” – Niels Bohr
45. “Every sentence I utter must be understood not as an affirmation, but as a question.” – Niels Bohr
46. “Physics is the belief that a simple and consistent description of nature is possible.” – Niels Bohr
47. “Opposites are not contradictory but complementary.” – Niels Bohr
48. “If quantum mechanics hasn’t profoundly shocked you, you haven’t understood it yet.” – Niels Bohr
49. “You must come to Copenhagen to work with us. We like people who can actually perform thought experiments!” – Niels Bohr
50. “If you think you understand it, that only shows that you don’t know the first thing about it.” – Niels Bohr
51. “In the great drama of existence we are audience and actors at the same time.” – Niels Bohr
52. “The opposite of a correct statement is a false statement. But the opposite of a profound truth may well be another profound truth.” – Niels Bohr
53. “We are trapped by language to such a degree that every attempt to formulate insight is a play on words.” – Niels Bohr
54. “We are suspended in language.” – Niels Bohr
55. “An expert is a man who has made all the mistakes which can be made in a very narrow field.” – Niels Bohr
56. “Address to Albert Einstein: You are not thinking. You are merely being logical.” – Niels Bohr
57. “A physicist is just an atom’s way of looking at itself.” – Niels Bohr