What is state preperation? Googled it however could not understand lingoWernerQH said:The quantum processes in the interior of the sun can be successfully described using QM, yet some people insist on a description in terms of "state preparation" and "measurment"
In terms of basic QM, i.e., without adopting any particular interpretation, this question can't be answered, since "collapse of the wave function" is not treated as a "real" process; it's just something you do in the math in order to make accurate predictions after you know the result of a measurement. See this Insights article:Dr3vil said:What collaspes the wave function
In terms of the 7 Basic Rules that I linked to in my previous post just now, "state preparation" is any process that produces quantum systems in a known pure state (Rules 1 and 2 describe what a "quantum system" and a "pure state" are).Dr3vil said:What is state preperation?
You are correct - it is not very good at all. In fact, some like What The Bleep Do We Know Anyway are downright nonsense. Here is the truth. Peter has already pointed to the axioms, but they are not the last word. There is something called Gleason's Theorem:Dr3vil said:Summary:: What collaspes the wave function ... human eye balls or physical measuring device
Im confused What collaspes the wave function ... is it a human eye ball or physical measuring device. The way QM is described on youtube for layfolks is not very good. They make it sound like the physical observer collaspes the wave function ... however its a physical device interacting with the wave function that's collasping it isn't it?
State preparation can also be a preparation in a mixed state. E.g., putting a gas with a fixed number of atoms/molecules in a container at some fixed temperature is a preparation of the gas in the statistical operator of the canonical ensemble: ##\hat{\rho}=\exp(-\beta \hat{H})/Z##.PeterDonis said:In terms of the 7 Basic Rules that I linked to in my previous post just now, "state preparation" is any process that produces quantum systems in a known pure state (Rules 1 and 2 describe what a "quantum system" and a "pure state" are).
It is not well defined. The thing that collapses the wave function is typically called an "observer" or "measurement device", but quantum mechanics itself does not say what it is, and you have to supply this by ill-defined common sense. This observer collapses the wave function when a measurement is made, and a measurement result is obtained. Again, one has to rely on ill-defined common sense to know when a measurement result is obtained.Dr3vil said:Summary:: What collaspes the wave function ... human eye balls or physical measuring device
The observer in quantum mechanics refers to any entity that measures or observes a quantum system. This can be a person, a machine, or any other measuring device.
No, the observer does not cause the collapse of the wave function. The collapse occurs due to the interaction between the quantum system and the measuring device, not because of the observer's consciousness or intention.
No, the observer's role is simply to measure the state of the quantum system. The outcome of a quantum experiment is determined by the laws of quantum mechanics and cannot be influenced by the observer.
Yes, the observer is necessary for quantum mechanics to work as it allows us to gather information about the quantum system. Without an observer, the quantum system would exist in a superposition of all possible states and we would not be able to make any predictions or measurements.
No, quantum mechanics and the observer do not violate the principle of causality. The collapse of the wave function and the outcome of a quantum experiment are still determined by cause and effect relationships, but at the quantum level, these relationships may be probabilistic rather than deterministic.