Hup Definition and 67 Threads

Hello, Suppose you are on a boat and your friend is on another boat behind you. if you have a volley ball and you throw it at front direction and, by magic, the ball desappears and reappears behind you and your friend, such that pushes your friend to you. This magic is permitted by "...

Hi, I was watching a pop-sci TV program on heat recently. Specifically, it was about trying to reach the lowest temperature possible. I was trying to recall something I learned about the uncertainty principle being a barrier to reaching absolute zero. When I searched on the internet I got...

I hope this question relates closely enough: [Mentor note: Don't be afraid to start a new topic if your question isn't directly related to an existing one. :smile: Also, this is really a QM question so I'm moving this to the Quantum Physics forum while I'm at it.] If the 'controls' of an...

I am kinda confused on the whole electrons falling into the nucleus thing (I know you guys have probably seen this question a million times but when I searched the forum, I could hardly find a satisfying answer :frown: ) So I have heard that the reason electrons don't fall into the nuclues is...

A sinusoidal EM wave which length l is very great, hits a photoelectric device. According to HUP, a sinusoidal EM wave with finite length l has a spectrum of frequencies which broadness is inversely proportional to l. So, if l is very great, the energy uncertainty is very low, and this, still...

Hi, All my chemistry textbooks (thankfully not the physics ones) and my teachers (unfortunately including the physics ones) seem bent on 'explaining' the Heisenberg Position-Momentum Uncertainty Principle using the famous thought experiment of photons striking an electron, and not one of them...

Did you guys get this link yet? http://www.news.cornell.edu/stories/Sept06/schwab.quantum.html Simply amazing.

If the universe did not act in accordance with the HUP would it display different properties to the universe we know and love? A large number of people have difficulty accepting the underlying concept of the universe being undefined but what would be the alternative? Would the universe be...

In QM a photon with wavelength comparable to the width of a slit, will pass through and create a 'Gaussian Distribution' on a screen. As the slit width is decreased (gets thinner), the 'GD' on the screen will counterintuitively INCREASE (aka. widen). My question is it possible that the slit...

Here is one I am having trouble following. Can anyone help me through my confusion? Our setup is a normal Bell test using entangled photons created using spontaneous parametric down conversion (PDC). Such a setup uses 2 BBO crystals oriented a 90 degrees relative to each other. See for...

"When a positron emitted in beta+ decay annihilates with an electron, the combined mass of the two particles, m = 2me, is converted into an amount of energy 2mec^2 in the form of two 511 keV gamma rays. Momentum conservation requires that the two gamma ray photons are emitted in opposite...

Sorry for this first year level question but something is really not clear in my head concerning the Heisenberg's uncertainty principle. First remark: my question here is neither a critic of this principle nor a tentative to collapse it. No; I consider the propagation of the light in the air or...

Apologies to those I've already driven mad with questions on HUP and particle-antiparticle annihilation, but here's three more. I was reading Feynman's Lectures wherein he explains why electrons do not combine with protons in hydrogen atoms. This was the same answer I got to my question of...

A ball of mass 50g moves with a speed of 30 m/s. If its speed is measured to an accuracy of 0.1%, what is the minimum uncertainty in its position? What does this answer indicate about the relevance of quantum mechanics to macroscopic objects? I am completely confused. My prof just gave us...

I believe we should talk about debunking crazy stuff like Quantum Mechanics, especially the Heisenberg Uncertainty Principe. People believing in HUP (in fact a type of religion) - an absolutely crazy concept - are believe in pseudo science. Superposition is superstition. The Schrödinger cat is...

A reply in a different thread got me thinking. The Heisenberg Uncertainty principly is really a mathematical expression about the noncomutative behavior of operators, that is (using the standard position and momentum) p q - q p >= i h / 2 pi. But aren't both position and momentum strictly...

How does the Heisenberg uncertainty principle work within string theory, considering that the strings's size is on the order of Planck's constant?