Author: haroonkhan
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The Atomic Spiral
We explained away doubts about the stability of Rutherford’s nuclear atom by stating, simply, that the electron must orbit the nucleus like the moon about Earth. We confess now to telling you only half the story. By setting the electron in motion about the nucleus, we actually doomed it to an even grimmer fate. The…
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Revisiting the Atom
We return now to England to see if there have been any new developments in the theory of the atom. Ernest Rutherford had just unveiled a new model for the atom—the nuclear atom—that seemed to be in better agreement with experimental observation than the plum pudding model of J. J. Thomson. Since then, little new…
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Introduction
We will revisit the atom, and learn how the decisive blow in the battle between Thomson’s plum pudding model and Rutherford’s nuclear model was dealt by a student of them both. We will learn about yet another success of quantum ideas, this time to explain the inner (and outer) workings of the atom. We’ll discover…
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Wave-Particle Duality, Take 1
The story of quantum physics, it’s worth reflecting on the importance of Einstein’s “heuristic principle.” He explained, and experiments later verified, that light travels in the form of compact, localized, and indivisible chunks. But you’ll recall that there are a few instances, like interference and diffraction, where a wave theory does the trick. It sure must…
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The Compton Effect
Although Einstein managed to chalk up several successes for his photon concept, he failed to come up with the slam-dunk needed to earn universal acceptance. Such proof eventually came from an important experiment that relied, believe it or not, on Newton’s laws of motion. (Truth be told, it required just a smidge of Einstein’s theory…
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The Photon
The application of the scientific method. There was a problem, he formulated a hypothesis, tested it against an experiment, and then concluded that he was on to something. After chalking up a few more successes, which we won’t go into here, it appeared that his hypotheses were consistent with all relevant observations of the photoelectric…
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The Heuristic Light-Quanta
What the heck is going on here? These findings were in stark contradiction to classical prediction, and they puzzled physicists for many years. The world had to wait for the one-and-only Albert Einstein to solve the problem. In a 1905 article that was nothing short of luminary, he proposed an elegant solution that explained everything,…
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Maxwell Stumbles Again
We know that Planck was a great physicist because Planck’s constant is named after him. Likewise, the strength of forces is measured in units named after Newton. So you shouldn’t be surprised to learn that the physicists’ unit for the frequency of light waves is named after the man who first demonstrated that light really…
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Introduction
We explore a second important case of quantization, this time in the form of light quanta, and learn how it provides an elegant interpretation of Max Planck’s blackbody radiation solution. We’ll also learn how the discovery of light’s particle nature can be traced back to the very experiment that proved it was a wave. We’ll…
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Energy Quantization and You
Though it wasn’t fully recognized during Planck’s time, his quantum hypotheses can be generalized beyond oscillating charges in blackbodies to any oscillating system, be it a little girl on a backyard swing, a sloshing wave of seawater, or a retired thrill-seeker dangling from a bungee cord. In contrast to our artificial “quantum staircase” from the…