# Quantum Physics

- Mathematical description of the motion and interaction of subatomic particles. Quantum Mechanics & Field Theory
 Views: 734 Announcement: End of year contest, $75+$50 prize! Dec18-13 Meta Thread / Thread Starter Last Post Replies Views Pinned: Quantum Physics Forum Rules Before posting anything, please review the Physics Forums Global Guidelines. If you are seeking help with a... Feb23-13 09:38 AM ZapperZ 1 27,792 There are few questions on an assignment (taken from an old exam, YIKES!) that are confounding me and I was wondering... Apr10-13 08:31 PM ace1719 0 437 I've found many articles online that explain how to solve the Schrodinger equation for a potential dependent on x, but... Apr15-13 08:29 AM DrDu 4 650 Hi- I'm trying to calculate the effect of a magnetic field on some spectral lines. I know that each energy... Sep14-11 07:38 PM Acetylene5 1 1,232 Hi! If two particles are entangled, A and B, and someone messes with A, have scientists determined the speed at which... Aug7-05 12:00 PM DrChinese 2 912 Hi! This may be a stupid question, but here goes. Is it possible to do a measurement to determine if a photon's... May18-08 03:14 PM peter0302 1 1,153 why is there an upper limit to the photon energy that can be observed in the emission spectrum of the hydrogen atom? Aug8-10 07:59 PM Eudoxie 2 2,758 The problem statement, all variables and given/known data Debye considered atoms to oscillate from 0 up to a nu... Apr10-11 10:44 PM acherentia 3 2,117 Hello everybody, recently in my quantum mechanical course we were introduced to the concept of the quantum harmonic... Feb10-12 08:21 AM questionpost 6 1,232 Hello everybody, I was revising for my quantum mechanics course and I was wondering why when we approximate the bond... Feb25-12 10:13 AM achilleasatha 0 563 Hello all. I'm in an introductory QM course as a physics major. As I understand it, one has an eigenfunction of an... Sep24-07 01:37 PM monish 9 1,966 Hi, since you answered my last Weinberg question so nicely, I'm gonna try another one of those. In discussing the... Dec21-09 05:18 AM acipsen 0 557 I'm having some trouble understanding the idea of coherence. Consider the phrase: "a coherent superposition of... Apr22-07 06:59 PM acme37 2 1,631 Forgive me if I am putting this in the wrong place, but this is my first post here. The question that I have is... Nov12-09 07:09 PM strangerep 1 1,244 Since antiparticles have reversed proper time, can I conclude that all invariants are reversed for antiparticles? Jul28-06 06:15 PM actionintegral 9 1,116 I learned a lot from the discussion of the converse problem, photon absorption. What about this case? Perfectly... Oct4-06 09:58 AM actionintegral 17 2,122 I hear a lot about nonlocality and it's relationship to quantum mechanics and relativity. But I don't know anything... Oct4-06 04:12 PM DrChinese 3 1,457 Ok - here goes: I see the energy levels of the harmonic oscillator as E = hw(n+1/2) = hwn + hw/2 (please... Oct19-06 05:59 PM Haelfix 2 1,165 Hello, I was wondering about the Shroedinger equation. I know about the "particle in a box" solution, but I was... Nov7-06 09:26 AM quetzalcoatl9 7 3,507 I wanted to know what the term "virtual particles" referred to. I found many "descriptions" of them on webpages. Fine.... Dec3-06 04:27 PM reilly 30 4,126 Is there an analogy between total internal reflection and quantum tunneling? And did I spell tunnelling right? Nov21-06 04:17 PM Doc Al 1 1,564 Time dependent perturbation theory... second order term... For some reason they replace ... Nov27-06 11:27 AM Meir Achuz 1 3,277 We were learning about Dirac's relativistic equation. The teacher wrote on the board: Free Particle Dirac Equation:... Dec4-06 01:42 AM Epicurus 13 1,914 Hello, I am new to this forum. This is an excellent, informative forum; therefore, I felt compelled to join. I... Mar29-12 09:36 AM JamesOrland 28 2,206 I'm new to this, so I can only express and understand simple language (as far as quantum mechanics is concerned).... Feb10-09 11:00 AM jambaugh 3 837 Got me some energy e-states Psi(x,t) = blah blah.. I am asked to normalize, blh blah blah.. got that. Then i'm asked... Sep22-04 06:45 PM Ad Infinitum NAU 2 2,570 So, as I have found out through my exhaustive search for a solid grad program, it is hard to find a close-knit group... Feb17-06 09:35 AM DavidK 1 1,313 Greetings. I was reading a rather non-descriptive page about Bose-Einstein Condensates. I've never really read... Feb12-04 07:01 PM Adam 2 1,244 Oh, by the way, the reason I asked about BECs the other day is this new discovery of Fermionic Condensates:... Feb16-04 05:38 PM Adam 0 1,735 Suppose an electron crosses worldlines with me such our relative velocities v are a substantial fraction of that of... May23-12 06:02 PM jfy4 1 622 Hello, I am trying to reproduce Bell's calculation for the expectation value of paired spin measurements on... Jul21-12 12:47 PM Adam Lewis 1 602 Hello everyone, im new to this forum, and to physics really, so i apologize in advance for silly mistakes. ... Dec14-11 04:32 PM AdamBenHamo 10 1,643 Just a quick question, that I'm not completely clear about; Quantum tunnelling allows particles to overcome... Nov13-12 12:03 PM AdamBenHamo 2 378 Hey guys I'm new here. I'm a sophomore in college and am very interested in learning QM, with a more math oriented... Jan20-07 09:51 PM ccesare 10 2,070 Good morning! I am trying to understand the mechanism of light reflectance in a quantum context. Diffused light... Jan3-05 06:26 PM trosten 1 1,181 Is Quantum entanglement really true ?, they say that that have observed it with photons and the distance between the... Feb29-12 09:44 AM DrChinese 3 873 I'm reading Griffiths', and I had a question about the harmonic oscillator. Griffiths solves the Schrodinger... Jul18-08 12:54 PM adartsesirhc 2 1,342 Hi, this is my question: suppose that at time t' our system is in the state | \psi(t')\rangle The probability for... Jul27-10 07:15 AM inempty 4 1,041 Hi, i would ask you an opinion about a (maybe stupid) doubt. Let us think of a 1D lattice whose sites distant from... Sep23-12 06:36 AM AdeBlackRune 3 556 Is it generally true that the wavepacket of a free particle spreads out as time goes to infinity? It seems like it... Jun2-08 12:49 AM Adeimantus 8 1,859 So here is my question. Have a 2-D electron gas where: E = P(x)^2/(2m) + P(y)^2/(2m) Where p^2= p(y)^2 +... Apr29-07 11:55 AM StatMechGuy 1 980