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Philip Ball

Philip Ball Quotes

Science writer

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Famous Philip Ball Quotes

“Everything that seems strange about quantum mechanics comes down to measurement. If we take a look, the quantum system behaves one way. If we don’t, the system does something else. What’s more, different ways of looking can elicit apparently mutually contradictory answers. If we look at a system one way, we see this; but if we look at the same system another way, we see not merely that but not this. The object went through one slit; no, it went through both. How can that be? How can ‘the way nature behaves’ depend on how – or if – we choose to observe it?”

“When it’s said that quantum mechanics is ‘weird’, or that nobody understands it, the image tends to invite the analogy of a peculiar person whose behaviour and motives defy obvious explanation. But this is too glib. It’s not so much understanding or even intuition that quantum mechanics defies, but our sense of logic itself. Sure, it’s hard to intuit what it means for objects to travel along two paths at once, or to have their properties partly situated some place other than the object itself, and so on. But these are just attempts to express in everyday words a state of affairs that defeats the capabilities of language. Our language is designed to reflect the logic we’re familiar with, but that logic won’t work for quantum mechanics.”

“So long as we don’t try to figure out which slit [electrons] go through, they will behave as if they go through both at once. But if we try to pin down which slit they pass through, they only go through one. The mere act of making the measurement – even if we can be pretty sure that the measurement shouldn’t obstruct or influence the electron’s path – appears to turn a wave into a particle. Yes, appears to. Does the electron really pass through both slits at once when we’re not looking at its path? Does it change from wave to particle when we do look? These are, according to Bohr’s view of quantum mechanics, illegitimate questions, precisely because they are insisting on some microscopic description underlying the measurements we make. Bohr argued that there is nothing in quantum mechanics that permits us to formulate such a description. That is not what the Schrödinger equation is about. It just predicts the outcomes of measurements.”