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Questions tagged [heisenberg-uncertainty-principle]

This tag is for Heisenberg's quantum mechanical uncertainty principle. DO NOT USE THIS TAG for uncertainty in a non-quantum measurement.

This tag is for Heisenberg's uncertainty principle in quantum mechanics. DO NOT USE THIS TAG for uncertainty in a non-quantum measurement: Use the tag instead.

The Heisenberg Uncertainty Principle (HUP) states that $\sigma_x\sigma_p\geq\frac{\hbar}2$. This comes from the non-commutativity of matrix multiplication in Heisenberg's & Pauli's matrix mechanics.

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Heisenberg uncertainty principle, what is it?

Heisenberg uncertainty principle (HUP), what is it? Before this gets marked as a duplicate, i've went through most of the posts here already, many of them multiple times. I've went through countless resources (youtube, wikipedia, etc.) and for years…
Yogi DMT
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Feynman's example of why Heisenbergs uncertainty relation must hold

In the Feynman lectures on physics, Feynman gives an example where the Heisenberg uncertainty relation must hold true (http://www.feynmanlectures.caltech.edu/III_01.html). Specifically he writes: "Let us show for one particular case that the kind of…
Morty
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Would something like the uncertainty principle arise even if the universe was built on something like Newtonian mechanics?

I am thinking of a (greatly simplified) computer simulation of a universe that followed something like Newtonian rules. Inside the simulation are A.I.s that are made from those same rules, and can only use those rules interact the world around…
user840
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What is the uncertainty principle?

I looked on Wikpedia for information on the uncertainty principle, but after reading it I still had no idea. I know it has something to do with how many things you can hold at some spot for some amount of time (maybe?). This is inspired by this…
Tdonut
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Is there a Heisenberg Force?

If I read him correctly, in his book Quantum Theory, David Bohm argues that the reason an electron doesn't collapse into the nucleus is there is essentially a pressure due to the uncertainty principle opposing the Coulomb attraction. His book is the…
R. Romero
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How does the Uncertainty Principle work?

In my textbook they have explained the Heisenberg's uncertainty principle using the example where you cannot measure the position of the electron using the photon because the wavelength of the photon needs to be small which then causes it to have…
user662650
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Why does the uncertainty principle relate position and momentum when mass is always certain?

Why do physicists relate $x$ and $p$, instead of $x$ and $v$ since mass is well known and is not uncertain?
Shamisen Expert
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Physical meaning of uncertainty principle + question on symmetry

A question on the Uncertainty principle. So we know that it says (for position and momentum) that: $$ \Delta x \Delta p \ge \hbar/2. $$ Where $\Delta p = \sqrt {\langle p^2\rangle - \langle p\rangle^2 }$ and $\Delta x = \sqrt {\langle x^2\rangle -…
SuperCiocia
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Can measurement of the momentum of a particle can be done without observing its position?

Uncertainty principle says that one cannot measure exactly the position and momentum of a particle at same time. As per common understanding when we are measuring momentum of an object it is implicit that we aware of its position. My doubt is in…
Siva Kumar Valiveti
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Uncertainty principle and digital camera

I recently got into a discussion in how far (miniaturized) digital cameras are affected by the uncertainty principle. Specifically the question was, whether the uncertainty principle is one of the reasons why smaller digital cameras (with smaller…
user116514
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How does helium 2 at superfluidity occupy the same quantum state

As my question states, at 2K and below, helium 2 is a superfluid that apparently can defy the laws of entropy. This is explained that at this temperature, all atoms are in the same quantum state. Doesn't this violate the exclusion principle?
Rick
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What does simultaneity mean in Heisenberg's uncertainty in terms of the experimental apparatus?

I understand that the wave function of some system at some point in time can't be an eigen state for both the position and the momentum operators simultaneously. Here is what I am asking about, assume we make an experiment and in this experiment I…
Jack
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Is it Possible that Heisenberg's Uncertainty Principle has Observable Macroscopic Consequences?

HUP is generally discussed (specially in traditional books) as a consequence of quantum mechanics that's generally better (or even only) illustrated with microscopic physics. Even though I'm not the most careful of people, I've been careful enough…
joigus
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Why cant we lower temperature to X where if an electron is observed it will be as if its an unobserved Temperate Y

Lets say the temperature is Y, and we want to observe an electron but if we do we will use a high energy light wave which will make it act more like a particle, so why dont we just lower the temperature to X where after the high energy light wave…
Octavylon
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Do electrons have definite and single value of momentum and position?

Do electrons (individually) have definite and single value of momentum and position or do they simultaneously have multiple position (a spread) at a time? In other words, according to the uncertainty principle, is it just impossible to measure the…
raindrop
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