# Quantum Physics

- Mathematical description of the motion and interaction of subatomic particles. Quantum Mechanics & Field Theory
 Meta Thread / Thread Starter Last Post Replies Views Views: 1,895 Announcement: Follow us on social media and spread the word about PF! Jan16-12 Pinned: Quantum Physics Forum Rules Before posting anything, please review the Physics Forums Global Guidelines. If you are seeking help with a... Feb23-13 08:38 AM ZapperZ 1 36,357 If I set up an interference experiment and make one path much longer than the other would I still see an interference... Feb9-06 05:53 AM vanesch 1 1,251 I was reading some some popular science rags and came across an article that espoused: But I didn't think all... Feb12-06 04:07 PM QuantumUnbound 0 2,489 I'm working on a research paper on Quantum Entanglement and came across something I don't understand. (I assume this... Dec17-09 11:21 PM QuantumVegan 8 2,001 http://imageshack.us/photo/my-images/40/63636538.png/ Feb14-13 02:39 AM QuantumWild 0 372 Before I make my post, I'd just like to introduce myself. My nickname is quantum_foam, as you can see (it's from the... Nov8-03 11:35 PM quantum_foam 4 1,248 In F. Wilczeks book, The Lightness of Being he describes his theory on the origin of mass. He explains, in much more... Jan10-09 01:56 PM malawi_glenn 2 810 OK, I have a problem with the many-world interpretation, namely the quantum suicide experiment. My problem: How... Jun28-06 11:32 PM koantum 58 7,986 Imagine you have two plates which can either be perfectly conducting or perfectly insulating by changing some... Nov5-06 07:34 PM Epicurus 8 1,914 I am reading chapter three of Huang's Statistical Mechanics and I have a problem with equation (3.22). Having... May19-12 08:03 AM QuArK21343 2 589 I am told that when an atom absorbs a photon, it jumps up an energy level, these are discrete levels of energy etc... Apr7-11 07:41 PM Einstein Mcfly 3 864 Hi, I have a ground state wavefunction, $$\psi_0(\xi) = A_0\exp(-\frac{1}{2}\alpha\xi^2),$$ (##\alpha## is a... Dec13-13 07:45 AM quarkgazer 0 384 Since it appears (so far) I am infringing no rule, here is another shameless copy/paste of a thread I started on... Oct24-08 06:19 PM Haelfix 1 1,174 Hi In double slit experiment our observe can change the past and in the entanglement our observe affact other... Dec13-13 09:44 AM Quarlep 10 750 Spin is a quantity of vector but I dont know how to add them ? Please be simple Thanks Aug14-14 09:19 AM Quarlep 2 165 I watched a video about particle physics and there I saw something strange(for me)... Aug18-14 02:18 AM MrRobotoToo 6 369 Why is there no kinetic energy term in said hamiltonian? Suppose I take a magnetic dipole in my hand, and I throw it... Dec24-05 11:17 AM abszero 3 6,286 I've always wondered what is considered to be 1 photon. We always see things like "When two of these particle collide,... Nov27-08 09:46 PM enotstrebor 34 10,872 I am reading the first chapter of Sakurai's Modern QM and from pages 30 and 32 respectively, I understand that (i)... Aug11-06 03:21 AM dextercioby 5 1,474 The SE is written in terms of a potential energy. It says, "given a particle in a region where the potential is... Oct4-06 08:29 PM Galileo 4 1,951 How should \Delta E \Delta t \geq \hbar/2 be interpreted? When does it apply? Delta t refers to the time of what? etc.... May7-12 06:40 AM Demystifier 10 8,311 In Reif's thermo book, one can read "Consider a substance which contains n magnetics atoms per unit volumes and... Nov13-06 10:57 AM quasar987 5 5,092 In my thermo text, they consider a diatomic molecule that is rotating about the axis joining the two atoms (also the... Nov14-06 09:42 PM quasar987 5 2,287 Hi, I have a problem with the very nature of time dependant perturbation theory (TDPT). In TDPT, we consider a... Mar16-07 02:23 PM vanesch 3 1,493 Hi, Is there an explicit formula for the eigenfunctions of the harmonic oscillator? By explicit, I mean "not... Mar27-07 03:30 AM christianjb 8 4,073 As I understand (from reading p. 2-06 of Marle's 1975 text on geometric quantization available on the french wiki page... Mar25-12 09:37 AM fzero 9 1,407 So, I'm pretty sure this is trivial, but I just want to be sure: My QM book frequently uses both the terms... Oct27-08 01:25 AM newbee 2 1,116 I have been reading about some quantum gravity topics, and am wondering: how many different modifications to the... Nov7-08 03:09 AM Haelfix 3 1,160 I was thinking about bound and unbound states the other day and want to know: Is unboundedness a requirement for a... Jul29-09 01:45 PM maverick_starstrider 1 978 I need someone to tell me if I'm understanding things. :shy: Let's say that we're studying the infinite square well... Aug26-09 10:11 AM olgranpappy 3 688 Can anyone expand on the relationship between Lie groups, Lie algebras, exponential maps and unitary operators in QM?... Sep29-09 01:00 PM meopemuk 4 1,106 I'm reviewing my undergraduate quantum mechanics from a while back, and I am not quite sure I understand this... Jan28-10 02:51 PM PhilDSP 8 1,538 I am having trouble understanding how a wavefunction for three or more particles can be totally antisymmetric. Does... Feb14-10 02:32 PM ansgar 1 685 After reading Seth Lloyd's book “Programming the Universe”(only once) I came up with a few questions. The way I... Jul21-07 12:16 PM vpoko 1 1,094 I am wondering about acceleration in quantum mechanics. Let's consider spherically symmetric potential V(r). From the... May19-13 08:56 PM HomogenousCow 4 676 Consider a particle approaching a finite potential step or inside a potential well. As we know, the particle has a... Jun14-12 10:35 AM Demystifier 9 1,717 This is perhaps a stupid question, but are the field equations, for example, for QED useful for anything? By field... Jun15-14 10:04 AM QuasiParticle 14 1,283 Does the measurement problem ("wave function collapse") or something similar somehow manifest itself in QED and other... May25-14 09:47 AM DrDu 44 1,350 I was thinking if you entangled both the electron and positron in a states that both of thier orbitals don't interact.... Aug10-05 06:12 PM Rade 1 1,733 I was wondering that if neutrons stablize that atomic nuclei then it should stablize other systems. Or can other... Nov23-11 12:29 PM 0800peter 10 2,422 Is there any way to stablize these particles? Aug11-05 01:27 AM quasar987 1 1,151