Sean Carroll
Let's conjure some science up in here. Science is good for the soul. Today: what are "quantum fluctuations," anyway? #qf
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Zero-point energy, virtual particles, the Lamb shift -- all due to vacuum fluctuations. But notice something important...
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Nothing actually "fluctuates" in vacuum fluctuations! The system can be perfectly static. Just that quantum states are more spread out. #qf
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Measurement Fluctuations are the bridge b/w Boltzmann and Vacuum fluctuations. They occur when you repeatedly observe a quantum system.
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By itself, a system can be static, but observational outcomes are probabilistic. Observe over and over again, get different results.
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That makes us confuse (static) vacuum fluctuations with (dynamical) Boltzmann fluctuations. We think what we see is what really is.
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But quantum mechanics says that what really exists is very different from what we see. In an atom, electrons aren't fluctuating at all.
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All of which is crucial for understanding Boltzmann Brains. A topic for another day. For more see: http://arxiv.org/abs/1505.02780
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Worth pointing out that my discussion of quantum fluctuations betrays my Everettian (many-worlds) sympathies. Your mileage may vary.
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@seanmcarroll You're blowing my mind. Are you saying that random quantum fluctuations don't actually happen? Or that they have no effect? -
@NickFalacci Vacuum fluctuations exist, but they’re always there - not flashing in&out of existence.
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@seanmcarroll as I understand the word "fluctuation" it means instability of state as measured by 'std deviation' relative to an observable. -
@seanmcarroll whether a state fluctuates (vacuum or not) depends on observable, does it not? (Esp. When we have complementary observables.) -
@seanmcarroll what do you mean by Quantum state is more spread out ?
Nicolas Falacci
Sam Walters
Alice Hussien Akkush
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