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If you balance the forces due to the electric and the magnetic fields on the charged particle in such a way that there is no resultant force on the charged particle, then that is called a velocity selector. It means that the Lorentz force on the particle is 0. $$ F =Q(E + v \times B) = 0$$ This allows you to measure the velocity of the charged particles ...


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It meant that all the electrons that he deflected with electric and magnetic field were all travelling at the same velocity. This meant that they were all deflected by the same amount and travelled along the same trajectory to hot the screen at the same place ie produced a well defined spot of light.


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I don't know about this particular paper, but I do know that several early supergravity computations were checked using a computer algebra program 'Abra' written in Pascal by Mees de Roo. You could do gamma matrix algebra and Fierz transformations with it (among others), and it had a quite clever method to interactively work on parts of long expressions. ...


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After an extended search through my copy of Pais' biography Niels Bohr's Times, I believe I have found what exactly what you are referring to. There were multiple times in his life when Bohr wrote about the definition of the word phenomenon. On pages 431-433 of my copy of Pais' book, Bohr's thoughts on this matter are summarized. I will now reproduce the ...


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who discovered [quarks] According to Wikipedia: The quark model was independently proposed by physicists Murray Gell-Mann and George Zweig ... and when The Wikipedia article continues: ... in 1964. The proposal came shortly after Gell-Mann's 1961 formulation of a particle classification system known as the Eightfold Way—or, in ...


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As far as I know, no notion of time travel before Herman Weyl's 1922 book "Space, time, matter", where he vaguely discusses the notion that the metric of spacetime could become so twisted as to allow time travel. I recall a 1917 special relativity book discussing the classical problem of a particle going faster than light going backward in time, but only to ...


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Terms like "Father of Physics" (or "Father of Modern Chemistry", or "Mother of Computer Science") aren't official titles, they're just subjective opinions. No one appoints them. Calling Einstein the Father of Physics is like giving your dad a "Best Dad in the World" mug--it's a nice gesture, but no one ever did a survey of every dad in the world to ...


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What is physically wrong with having electrons in an atom be unstably configured? Think of it like this. Imagine that you have a theory that describes how the atoms work, and where you use the best of you knowledge of electromagnetism and Newtonian mechanics. SO you place some positively charged points particles and some negatively charged points ...


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These responses do not really answer the question. Planck's distribution was explicitly provided by Planck to represent the distribution of energy for what are now referred to as a boson. The proposition of Bose, 24 years later, was a quite terse reiteration of the same geometric expansion, and to recommend it as a more general principle for thermal ...



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