Beyond Weird Quotes

“This picture of quantum mechanics is said to be ontic: from ‘ontology’, meaning the nature of things that exist. The alternative view is that the wavefunction is epistemic: as Heisenberg asserted, it refers only to our state of knowledge about a system, and not to its fundamental nature (if such a concept has any meaning). In this latter view, if a wavefunction changes because of something we do to the quantum system, it doesn’t imply that the system itself has changed, but only that our knowledge of it has.”
― Philip Ball, Beyond Weird: Why Everything You Thought You Knew about Quantum Physics Is Different

“when scientists refer to the wavefunction as real, what they mean is that there is a unique, one-to-one relationship between the mathematical wavefunction and the underlying reality it describes.”
― Philip Ball, Beyond Weird: Why Everything You Thought You Knew about Quantum Physics Is Different

“Is there some ‘element of reality’ that the wavefunction represents, or is it just an encoding of accessible knowledge about a quantum system?”
― Philip Ball, Beyond Weird: Why Everything You Thought You Knew about Quantum Physics Is Different

“This phenomenon is called quantum tunnelling. The electron (or any other quantum particle in such a situation) is said to be capable of tunnelling out of the box, even though from a classical perspective it lacks the energy needed to escape. Tunnelling is a real effect: it has been observed widely, for example in the way electrons get exchanged between molecules.”
― Philip Ball, Beyond Weird: Why Everything You Thought You Knew about Quantum Physics Is Different

“Electrons confined to particular orbits around the nucleus would have to have particular wavelengths – and thus frequencies and energies – so that a whole number of oscillations would fit long the orbital path, forming ‘standing waves’ rather like the waves in a skipping rope tied to a tree at one end and shaken (except that we can’t answer the question ‘waves of what?’).”
― Philip Ball, Beyond Weird: Why Everything You Thought You Knew about Quantum Physics Is Different

“The wavefunction is not a description of the entity we call an electron. It is a prescription for what to expect when we make measurements on that entity.”
― Philip Ball, Beyond Weird: Why Everything You Thought You Knew about Quantum Physics Is Different

“If so, we have to accept that, as far as quantum mechanics (and therefore current science) is concerned, there simply is no ‘where the electron is’.”
― Philip Ball, Beyond Weird: Why Everything You Thought You Knew about Quantum Physics Is Different

“complicated systems, like a molecule with many atoms. Once you have a good enough wavefunction, you can then use it to calculate all manner of properties: how the molecule will vibrate, how it will absorb light, how it will interact with other molecules.”
― Philip Ball, Beyond Weird: Why Everything You Thought You Knew about Quantum Physics Is Different

“Solving the Schrödinger equation to deduce a wavefunction is impossible to do exactly with pen and paper for anything but the simplest and most idealized systems. But there are ways of getting an approximate wavefunction for more complicated systems, like a molecule with many atoms.”
― Philip Ball, Beyond Weird: Why Everything You Thought You Knew about Quantum Physics Is Different

“The wavefunction encodes this information, and quantum math lets you extract it. There’s a particular operation you conduct on the wavefunction to find a particle’s momentum (mass × velocity), another operation to find its energy, and so on. In each case, what you get from this operation is not exactly the momentum, or energy, or whatever, that you’d measure in an experiment; it’s the average value you’d expect to get from many such measurements.”
― Philip Ball, Beyond Weird: Why Everything You Thought You Knew about Quantum Physics Is Different

“The Schrödinger equation, then, is an expression for finding out how an abstract entity called a wavefunction is distributed in space and how it evolves in time. And – here’s the really important thing – this wavefunction contains all the information one can possibly access about the corresponding quantum particle. Once you have the particle’s wavefunction, you can extract that information by doing something to it. For example, you can square it to find out the probability of finding the particle at any location in space.”
― Philip Ball, Beyond Weird: Why Everything You Thought You Knew about Quantum Physics Is Different

“How did Born know this? He didn’t. Again, he ‘guessed’ (and again, drawing on a wealth of physical intuition). And as with the Schrödinger equation itself, we still have no fundamental way of deriving Born’s rule.”
― Philip Ball, Beyond Weird: Why Everything You Thought You Knew about Quantum Physics Is Different

“The German physicist Max Born argued that the amplitude of the wavefunction squared (amplitude × amplitude) indicates a probability.”
― Philip Ball, Beyond Weird: Why Everything You Thought You Knew about Quantum Physics Is Different

“The wave in Schrödinger’s equation isn’t a wave of electron charge density. In fact it’s not a wave that corresponds to any concrete physical property. It is just a mathematical abstraction – for which reason it is not really a wave at all, but is called a wavefunction.”
― Philip Ball, Beyond Weird: Why Everything You Thought You Knew about Quantum Physics Is Different

“So the phrase ‘wave–particle duality’ doesn’t really refer to quantum objects at all, but to the interpretation of experiments – which is to say, to our human-scale view of things.”
― Philip Ball, Beyond Weird: Why Everything You Thought You Knew about Quantum Physics Is Different

“sense. In quantum theory, we do have to make statements like that. And then we can’t help asking what it means. That’s when the arguments start.”
― Philip Ball, Beyond Weird: Why Everything You Thought You Knew about Quantum Physics Is Different

“The key distinctions between classical mechanics and quantum mechanics, in Susskind’s view, are these: • Quantum physics has ‘different abstractions’ – how objects are represented mathematically, and how those representations are logically related. • Quantum physics has a different relationship between the state of a system and the result of a measurement on that system.”
― Philip Ball, Beyond Weird: Why Everything You Thought You Knew about Quantum Physics Is Different

“The best illustration I know of that quantization is rather incidental to quantum theory is found in the book Quantum Mechanics: The Theoretical Minimum, based on a series of lectures that Leonard Susskind, a professor of theoretical physics at Stanford University, gave to undergraduates, which were written up with the help of the writer Art Friedman.”
― Philip Ball, Beyond Weird: Why Everything You Thought You Knew about Quantum Physics Is Different

“For it is not so much a theory that one can test by observation and measurement, but a theory about what it means to observe and measure.”
― Philip Ball, Beyond Weird: Why Everything You Thought You Knew about Quantum Physics Is Different

“The physicist Leonard Susskind is not exaggerating when he says that ‘in accepting quantum mechanics, we are buying into a view of reality that is radically different from the classical view’.”
― Philip Ball, Beyond Weird: Why Everything You Thought You Knew about Quantum Physics Is Different

“Bohr, again, understood this point. He once gave a talk on quantum mechanics to a group of philosophers, and was disappointed and frustrated that they sat and meekly accepted what he said rather than protesting vehemently. ‘If a man does not feel dizzy when he first learns about the quantum of action [that is, quantum theory],’ said Bohr, ‘he has not understood a word.”
― Philip Ball, Beyond Weird: Why Everything You Thought You Knew about Quantum Physics Is Different

“What has emerged most strongly from this work on the fundamental aspects of quantum theory over the past decade or two is that it is not a theory about particles and waves, discreteness or uncertainty or fuzziness. It is a theory about information.”
― Philip Ball, Beyond Weird: Why Everything You Thought You Knew about Quantum Physics Is Different

“Feynman seemed to feel that it was impossible and even pointless to attempt anything comparable for quantum mechanics: We can’t pretend to understand it since it affronts all our commonsense notions. The best we can do is to describe what happens in mathematics, in equations, and that’s very difficult. What is even harder is trying to decide what the equations mean. That’s the hardest thing of all.”
― Philip Ball, Beyond Weird: Why Everything You Thought You Knew about Quantum Physics Is Different

“Here are the most common reasons for calling quantum mechanics weird. We’re told it says that: • Quantum objects can be both waves and particles. This is wave-particle duality. • Quantum objects can be in more than one state at once: they can be both here and there, say. This is called superposition. • You can’t simultaneously know exactly two properties of a quantum object. This is Heisenberg’s uncertainty principle. • Quantum objects can affect one another instantly over huge distances: so-called ‘spooky action at a distance’. This arises from the phenomenon called entanglement. • You can’t measure anything without disturbing it, so the human observer can’t be excluded from the theory: it becomes unavoidably subjective. • Everything that can possibly happen does happen. There are two separate reasons for this claim. One is rooted in the (uncontroversial) theory called quantum electrodynamics that Feynman and others formulated. The other comes from the (extremely controversial) ‘Many Worlds Interpretation’ of quantum mechanics. Yet quantum mechanics says none of these things. In fact, quantum mechanics doesn’t say anything about ‘how things are’. It tells us what to expect when we conduct particular experiments. All of the claims above are nothing but interpretations laid on top of the theory.”
― Philip Ball, Beyond Weird: Why Everything You Thought You Knew about Quantum Physics Is Different

“Or maybe, it’s sometimes said, the math tells us that ‘everything that can happen does happen’ – whatever that means.”
― Philip Ball, Beyond Weird: Why Everything You Thought You Knew about Quantum Physics Is Different

“Or perhaps we haven’t yet found the right math to answer questions about the world it purports to describe.”
― Philip Ball, Beyond Weird: Why Everything You Thought You Knew about Quantum Physics Is Different

“His failure, Feynman admitted, was to understand what the math was saying. It provided numbers: predictions of quantities that could be tested against experiments, and which invariably survived those tests. But Feynman couldn’t figure out what these numbers and equations were really about: what they said about the ‘real world’. One view is that they don’t say anything about the ‘real world’. They’re just fantastically useful machinery, a kind of black box that we can use, very reliably, to do science and engineering.”
― Philip Ball, Beyond Weird: Why Everything You Thought You Knew about Quantum Physics Is Different

“Feynman’s much-quoted words help to seal the reputation of quantum mechanics as one of the most obscure and difficult subjects in all of science. Quantum mechanics has become symbolic of ‘impenetrable science’, in the same way that the name of Albert Einstein (who played a key role in its inception) acts as shorthand for scientific genius.”
― Philip Ball, Beyond Weird: Why Everything You Thought You Knew about Quantum Physics Is Different

“[C]lassical physics is just a special case of quantum physics.”
― Philip Ball, Beyond Weird

“Here is the answer to Einstein’s question about the moon. Yes, it is there when no one observes it – because the environment is already, and without cease, ‘measuring’ it. All of the photons of sunlight that bounce off the moon are agents of decoherence, and more than adequate to fix its position in space and give it a sharp outline. The universe is always looking.”
― Philip Ball, Beyond Weird