Sidney Coleman, Quantum Mechanics in Your Face [1994]
Why Physics Stack Exchange recommends it
Physics Stack Exchange users link it when answering questions about measurement, collapse, entanglement, determinism and Bell-type arguments, as a clear and entertaining correction to the textbook 'collapse' picture.
Recommended by 4 people across 8 different months, 2012 to 2025.
What it is
A 1994 lecture by Harvard physicist Sidney Coleman, given at an American Physical Society sectional meeting, on the foundations of quantum mechanics. He argues against wavefunction collapse, treats the observer as a quantum system, and walks through entanglement, a GHZ-style 'Diehard' thought experiment, and many-worlds style reasoning.
What people said
Strong rec Robin Ekman · 2017-05 · Physics Stack Exchange · on “How can orbitals be oriented if the nucleus is symmetrical?”
Well, the real answer to that is that what you have been taught about "collapse of the wavefunction" is a caricature and not very helpful. My usual recommendation is this lecture [this video] with Sidney Coleman. But in brief: you need to treat also the measurement system as a quantum system and realize that it has to interact with the atom, and this interaction means that their states will be *entangled*. Suppose that the initial state is something like $|\psi\rangle |0\rangle$ where this means that the atom is in the state $|\psi\rangle$ and your detector
Recommends Arturo don Juan · 2016-01 · Physics Stack Exchange · on “I wanna learn Quantum Physics”
As others have stated, it really depends on why you want to learn quantum mechanics, and how deeply you want to learn it. (1) If you want to learn it as badly as you want to watch a movie at the movie theaters (i.e. not that badly - you're just mildly interested), then I'd recommend, aside from the books already mentioned, Mr. Tompkins in Paperback by George Gamow. It's a classically wonderful story book that plunges you into the wonderland of modern physics (up until the mid 1900's though). Also, I'd recommend watching a bunch of youtube videos of Richard Feynman. Richard Feynman (1918-1988) was a theoretical physicist with an extremely interesting personality and view of the world. Watchin
Recommends user12029 · 2017-07 · Physics Stack Exchange · on “Do quantum particles communicate?”
There are multiple ways to describe the same physical phenomena using the English language. A lot of these ways are valid and sensible and yet a lot are mutually contradictory. Your example demonstrates two contradictory English language explanations of the same physical phenomenon. The difficulty of answering a question like yours is that it can't really be answered in terms of physics, it has to be answered in terms of the English language. The bottom line is: quantum mechanics allows for correlations that are not possible in classical local speed-of-light-obeying physics. This can be interpreted in two ways: you can say quantum mechanics is classical and there is nonlocal instantaneous co
Recommends Andrew · 2021-01 · Physics Stack Exchange · on “Quantum mechanics observer one dies”
Essentially this exact question is addressed in Sidney Coleman's entertaining and interesting lecture "Quantum Mechanics in Your Face." See pages 8-10 of [LINK] The lecture is also on youtube, [this video]
Recommends Andrew · 2021-02 · Physics Stack Exchange · on “How does the many-worlds interpretation look like in bra ket notation?”
Part 3 of Sidney Coleman's lecture "Quantum Mechanics in Your Face" gives a nice description of how to think about it. You can read it on arxiv here: [LINK] (part 3 starts at the bottom of page 7) or watch it on youtube here [this video]
Recommends Andrew · 2023-08 · Physics Stack Exchange · on “How is quantum entanglement different from a controlled experiment where a pineapple is smashed at high speed and measuring a piece in air?”
You might be interested in Part 2 of Sidney Coleman's lecture "Quantum Mechanics in your Face", where he explicitly takes on a hypothetical physicist who insists quantum mechanics is really deterministic. There's a write up of the lecture here [LINK] and a video version here [this video]
Recommends Robin Ekman · 2025-02 · Physics Stack Exchange · on “In principle, could the Many-Worlds Interpretation be tested via interference?”
I'd also like to recommend Sidney Coleman's lecture Quantum Mechanics in Your where he talks about some of this. You can watch it on YouTube [this video] or read the transcript [LINK]
Recommends Andrew · 2025-03 · Physics Stack Exchange · on “Clarification regarding argument in EPR paper”
One explanation I really like of all this is Part 2 of Sidney Coleman's lecture Quantum Mechanics in Your Face, which has a writeup on arxiv [LINK] as well as a filmed version [this video] on youtube.
Cites Emilio Pisanty · 2012-06 · Physics Stack Exchange · on “What counts as a measurement?”
What you're describing is a large part of what's known as the measurement problem [LINK] , and it is quite certainly the main open problem in the study of the foundations of quantum mechanics. In the Copenhagen interpretation [LINK] of QM, one has a quantum mechanical system on one hand and a classical measurement device, which implies drawing a line somewhere between the two. One typically hopes that it doesn't really matter where the line is drawn and so far it's been possible (always!) to draw it somewhere so results match experiments. However, there's no clear physical principle for where to draw it, and your question ("when is a system big enough to count as a classical measurement devi
Cites Viesr · 2015-11 · Physics Stack Exchange · on “Quantum Mechanics in your face”
In this lecture Quantum Mechanics in your face by Sidney Coleman [this video] Does he state that there's only evolution according to Schrodinger's equation in QM and it is basically deterministic? (at around 45 minutes)