Frases de Niels Bohr
Niels Bohr
Data de nascimento: 7. Outubro 1885
Data de falecimento: 18. Novembro 1962
Outros nomes: Нильс Бор
Niels Henrick David Bohr foi um físico dinamarquês cujos trabalhos contribuíram decisivamente para a compreensão da estrutura atômica e da física quântica.
Licenciou-se na sua cidade natal em 1911 e trabalhou com Joseph John Thomson e Ernest Rutherford na Inglaterra. Em 1913, aplicando a teoria da quantificação aos elétrons/electrões do modelo atômico de Rutherford, conseguiu interpretar algumas das propriedades das séries espectrais do hidrogênio e a estrutura do sistema periódico dos elementos. Formulou o princípio da correspondência e, em 1928, o da complementaridade. Estudou ainda o modelo nuclear da gota líquida, e antes da descoberta do plutónio, previu a propriedade da cisão, análoga à do U-235. Bohr recebeu o Nobel de Física em 1922.
A sua teoria para a explicação do modelo atômico proposto por Rutherford em 1911, levando em conta a teoria quântica , não foi levada a sério. Depois, no decorrer e depois da década de 1920, vários físicos ajudaram a criar o modelo existente hoje. Entre estes físicos podemos citar, dentre outros, Albert Einstein, Louis de Broglie, Erwin Schrödinger, Werner Heisenberg e Wolfgang Pauli.
Citações Niels Bohr
„O sentido da vida consiste em que não tem nenhum sentido dizer que a vida não tem sentido.“
Frases Geniais - Página 247, Paulo Buchsbaum, Ediouro Publicações, 2004, ISBN 8500015330, 9788500015335, 440 páginas
Atribuídas
„Parem de dizer a Deus o que fazer com os seus dados.“
Stop telling God what to do
Niels Bohr citado em "Society" - página 146, Zelman Cowen (Sir.), William George Walker, Michael Donald Kirby - University of Queensland Press, 1986, ISBN 0702219975, 9780702219979
citação similar atribuida a Enrico Fermi
Disputadas
„Toda sentença que eu digo deve ser entendida não como uma afirmação, mas como um pergunta.“
Every sentence I utter must be understood not as an affirmation, but as a question.
como citado em "A Dictionary of Scientific Quotations" (1991) por Alan L. Mackay, p. 35 35
Atribuídas
„Predição é muito difícil, especialmente se for sobre o futuro.“
Prediction is very difficult, especially about the future.
citado in "Teaching and Learning Elementary Social Studies" (1970) de Arthur K. Ellis, p. 431
também atribuída a vários humoristas como o poeta dinamarques Piet Hein: "det er svært at spå - især om fremtiden"
como também atribuída ao cartunista dinarmaques Storm P (Robert Storm Petersen).
Disputadas
„We must be clear that when it comes to atoms, language can be used only as in poetry.“
In his first meeting with Werner Heisenberg in early summer 1920, in response to questions on the nature of language, as reported in Discussions about Language (1933); quoted in Defense Implications of International Indeterminacy (1972) by Robert J. Pranger, p. 11, and Theorizing Modernism : Essays in Critical Theory (1993) by Steve Giles, p. 28
Contexto: We must be clear that 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.
„Physics is to be regarded not so much as the study of something a priori given, but rather as the development of methods of ordering and surveying human experience.“
"The Unity of Human Knowledge" (October 1960)
Contexto: Physics is to be regarded not so much as the study of something a priori given, but rather as the development of methods of ordering and surveying human experience. In this respect our task must be to account for such experience in a manner independent of individual subjective judgement and therefore objective in the sense that it can be unambiguously communicated in ordinary human language.
„I consider those developments in physics during the last decades which have shown how problematical such concepts as "objective" and "subjective" are, a great liberation of thought.“
Remarks after the Solvay Conference (1927)
Contexto: I consider those developments in physics during the last decades which have shown how problematical such concepts as "objective" and "subjective" are, a great liberation of thought. The whole thing started with the theory of relativity. In the past, the statement that two events are simultaneous was considered an objective assertion, one that could be communicated quite simply and that was open to verification by any observer. Today we know that 'simultaneity' contains a subjective element, inasmuch as two events that appear simultaneous to an observer at rest are not necessarily simultaneous to an observer in motion. However, the relativistic description is also objective inasmuch as every observer can deduce by calculation what the other observer will perceive or has perceived. For all that, we have come a long way from the classical ideal of objective descriptions.
In quantum mechanics the departure from this ideal has been even more radical. We can still use the objectifying language of classical physics to make statements about observable facts. For instance, we can say that a photographic plate has been blackened, or that cloud droplets have formed. But we can say nothing about the atoms themselves. And what predictions we base on such findings depend on the way we pose our experimental question, and here the observer has freedom of choice. Naturally, it still makes no difference whether the observer is a man, an animal, or a piece of apparatus, but it is no longer possible to make predictions without reference to the observer or the means of observation. To that extent, every physical process may be said to have objective and subjective features. The objective world of nineteenth-century science was, as we know today, an ideal, limiting case, but not the whole reality. Admittedly, even in our future encounters with reality we shall have to distinguish between the objective and the subjective side, to make a division between the two. But the location of the separation may depend on the way things are looked at; to a certain extent it can be chosen at will. Hence I can quite understand why we cannot speak about the content of religion in an objectifying language. The fact that different religions try to express this content in quite distinct spiritual forms is no real objection. Perhaps we ought to look upon these different forms as complementary descriptions which, though they exclude one another, are needed to convey the rich possibilities flowing from man's relationship with the central order.
„Stop telling God what to do with his dice.“
A response to Einstein's assertion that "God doesn't play dice"; a similar statement is attributed to Enrico Fermi
Disputed
Variante: Einstein, don't tell God what to do.
Variante: Don't tell God what to do with his dice.
Variante: You ought not to speak for what Providence can or can not do. – As described in The Physicists: A generation that changed the world (1981) by C. P. Snow, p. 84
![The American Institute of Physics credits the photo [1] to AB Lagrelius & Westphal, which is the Swedish company used by the Nobel Foundation for most photos of its book series Les Prix Nobel., Niels Bohr's Nobel Prize biography, from 1922](https://commons.wikimedia.org/wiki/File:Niels_Bohr.jpg){kind=link}