Quantum Physics Forum

Join in expert discussion on quantum physics. Quantum physics is the mathematical description of the motion and interaction of subatomic particles. Quantum Mechanics and Field Theory.

Threads

Graduate Questions about measurement of a particle in superposition

  • entropy1
  • · Replies 14 ·
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14

Graduate How is this equation for <x|P|x'> derived?

  • baouba
  • · Replies 8 ·
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8

Undergrad What is the true nature of a photon's collapse?

  • wavepax
  • · Replies 3 ·
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3

Graduate Classical channel vs quantum channel

  • aaaa202
  • · Replies 2 ·
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2

Graduate Realism vs Locality in Quantum Entanglement

  • Markus Hanke
  • · Replies 41 ·
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Graduate Exploring E-e Repulsion: Stability of Half and Full P Sub-Shells Explained

  • htneT
  • · Replies 5 ·
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5

Undergrad Do photon apply a force to the electron ?

  • big_bounce
  • · Replies 11 ·
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11

Graduate Problem understanding Wigner's 1939 paper

  • facenian
  • · Replies 4 ·
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4

Graduate Superposition in relation to Counter factual definiteness

  • quantumphysics11
  • · Replies 3 ·
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3

Graduate Long-distance correlation, information, and faster-than-light interaction

  • edguy99
  • · Replies 97 ·
4
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Graduate Hermitian Operators: Understanding How They Work

  • amjad-sh
  • · Replies 16 ·
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Graduate Hamiltonian matrix for two electrons in a 1D infinite well

  • nothingisreal
  • · Replies 1 ·
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1

Graduate Simulating long-distance correlations

  • edguy99
  • · Replies 4 ·
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4

Graduate Penetrating the Rectangular Potential Barrier, E < V0

  • Chip
  • · Replies 1 ·
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1

Graduate What Are the Key Questions Surrounding Quantum Decoherence?

  • greypilgrim
  • · Replies 37 ·
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Graduate Why do the off-diagonal terms not matter in density matrices?

  • cube137
  • · Replies 7 ·
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7

Graduate Difference between Bell and CHSH?

  • jk22
  • · Replies 4 ·
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4

High School Can a Quantum Observer Perceive Superpositions Inaccessible to Humans?

  • cube137
  • · Replies 35 ·
2
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35

Undergrad Photon question (collision or no collision)

  • Psinter
  • · Replies 10 ·
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10

Graduate Quantum tunneling instantaneous

  • God Plays Dice
  • · Replies 4 ·
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4

Graduate How does the classical world emerge from the quantum world?

  • bremsstrahlung
  • · Replies 3 ·
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3

Graduate Perturbation theory, Intermediate states, Virtual particles

  • spaghetti3451
  • · Replies 1 ·
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1

Graduate Understanding Pure and Mixed Quantum States in Entanglement

  • daniellao
  • · Replies 4 ·
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4

Undergrad Why does a black body radiate in all the frequency spectrum?

  • Joker93
  • · Replies 7 ·
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7

Graduate High-Fidelity Qubit Readouts: Definition & Overview

  • Raptor112
  • · Replies 4 ·
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4

Graduate Understanding Quantum Purification

  • aaaa202
  • · Replies 1 ·
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1

High School What Happens to a Cat in a Box Without Factorization?

  • cube137
  • · Replies 42 ·
2
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42

Graduate Peskin and Schroeder - page 4 - choice of notation

  • spaghetti3451
  • · Replies 2 ·
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2

Graduate Ground state energies and potential

  • tyogav
  • · Replies 2 ·
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2

Graduate Non-locality: (FTL) 'influence' at all?

  • entropy1
  • · Replies 15 ·
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15

Graduate Quantum fluctuations within an electromagnetic field

  • J-eastwood
  • · Replies 2 ·
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2

Graduate Wigner function as average value of parity

  • naima
  • · Replies 2 ·
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2

Graduate About the expectation value of position of a particle

  • betelgeuse91
  • · Replies 6 ·
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6

Undergrad What do they mean that energy is quantized?

  • DGonzo2015
  • · Replies 20 ·
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20

Undergrad Black Body radiation and thermal equilibrium

  • Joker93
  • · Replies 2 ·
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2

High School Is it there or not (when we are not looking at it)?

  • Une Personne
  • · Replies 14 ·
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14

Undergrad Do Photons Have Mass and Why Does it Matter?

  • Evenus1
  • · Replies 34 ·
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Graduate Quantum Field Theory intro with flying field disturbances

  • edguy99
  • · Replies 2 ·
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2

Graduate Integrate Laplacian operator by parts

  • Eric_J
  • · Replies 2 ·
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2

Graduate Are probability coefficients source for semitransparence

  • sciencejournalist00
  • · Replies 5 ·
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5

Graduate Confused about EPR Thought Experiment

  • Thecla
  • · Replies 12 ·
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12

Graduate Electron-positron annihilation

  • sandy stone
  • · Replies 5 ·
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5

Graduate Quantum mechanics is not weird (locality and non-locality weirdness)

  • zonde
  • · Replies 162 ·
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High School How do scientists work with nonlinear crystals

  • sciencejournalist00
  • · Replies 23 ·
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23

Graduate Quantum entanglement by the means of beam splitters

  • sciencejournalist00
  • · Replies 34 ·
2
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34

Graduate Delta Function Identity in Modern Electrodynamics, Zangwill

  • chi_rho
  • · Replies 7 ·
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7

Graduate Average momentum of energy eigenstates is always zero?

  • taishizhiqiu
  • · Replies 10 ·
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10

Graduate Mathematical and actual measurements?

  • Zafa Pi
  • · Replies 7 ·
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7

Graduate Density Matrix and State Alpha

  • jlcd
  • · Replies 24 ·
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24

Graduate Can virtual particles exist without their counterparts?

  • J-eastwood
  • · Replies 7 ·
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7

Graduate From Classical to Quantum Mechanics

  • Joker93
  • · Replies 12 ·
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12

Graduate Radio Transmissions: Is It Possible in a 1x1x1m Cube?

  • SlowThinker
  • · Replies 1 ·
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Graduate Understanding superposition of states

  • misko
  • · Replies 1 ·
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Graduate Understanding proof for Heisenberg uncertainty

  • TheCanadian
  • · Replies 6 ·
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6

Graduate Time independent perturbation theory

  • Plaetean
  • · Replies 7 ·
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7

Graduate Decoherence in measurement apparatus

  • entropy1
  • · Replies 2 ·
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2

Graduate Momentum-free spinors and the Dirac equation

  • DiracPool
  • · Replies 2 ·
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2

High School Bell's Theorem basic question on contextuality & locality

  • jlcd
  • · Replies 6 ·
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6

Graduate Revisiting Neumaier's Newtonian Quantum: A Critical Perspective

  • jlcd
  • · Replies 2 ·
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2

Graduate Delta function and dirac notation

  • KostasV
  • · Replies 4 ·
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4

Graduate Derivation of number of quantum states

  • TheCanadian
  • · Replies 1 ·
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1

Graduate Bose-Einstein Stats and Planck Formula

  • modulus
  • · Replies 6 ·
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6

Graduate Is Complete Disentanglement Possible in Finite Time?

  • T S Bailey
  • · Replies 5 ·
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5

Graduate EPR paradox and time of collapse

  • thephystudent
  • · Replies 12 ·
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12

Graduate Parity and integration in spherical coordinates

  • KostasV
  • · Replies 4 ·
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4

Graduate S-matrix element for forward scattering and amputed green fu

  • FrancescoS
  • · Replies 1 ·
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1

Graduate Mirror plane and spin direction

  • Newstein
  • · Replies 1 ·
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1

Graduate Understanding the Propagation of Spherical Waves in Complex Quantities

  • TheArun
  • · Replies 5 ·
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5

Graduate Matrix elements of non-normalizable states

  • taishizhiqiu
  • · Replies 2 ·
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2

Graduate Does quantum entanglement in fact equal a wormhole?

  • Guthrie Prentice
  • · Replies 4 ·
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4

Graduate Measurement-Free Interactions (MFI)

  • PhysicsKid0123
  • · Replies 1 ·
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1

Undergrad What kind of differential equations one must know for QM?

  • Joker93
  • · Replies 2 ·
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2

Graduate Verify the Rodrigues formula of the Legendre polynomials

  • Happiness
  • · Replies 3 ·
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3

Graduate The Two-State Vector Formalism

  • Hybrid
  • · Replies 5 ·
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5

Graduate Quantum fluctuation and quantum mysticism

  • David Maroto
  • · Replies 42 ·
2
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42

Graduate What if there are no Schrödinger's cats?

  • Petr Matas
  • · Replies 24 ·
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24

High School Is Decoherence Possible Without Collapse?

  • jlcd
  • · Replies 5 ·
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5

Graduate Are infinitesimal field variations in QFT similar to coordinate components?

  • Mishra
  • · Replies 5 ·
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5

Graduate How does QFT handle non-locality?

  • PFfan01
  • · Replies 103 ·
4
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103

High School Quantization Explained: Understanding Photon Energy Packages

  • I'mnotarobot
  • · Replies 6 ·
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6

Graduate Quantum mechanics for big things?

  • AdrianHudson
  • · Replies 67 ·
3
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67

Graduate QFT: Understanding Counter-Terms for Renormalization

  • anthony2005
  • · Replies 6 ·
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6

Graduate If im not measuring its not there?

  • nnope
  • · Replies 29 ·
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29

Graduate Confusion about selection rules

  • AlonsoMcLaren
  • · Replies 4 ·
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4

Graduate Generator of Boosts: Classical Quantity?

  • pellman
  • · Replies 21 ·
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21

Graduate What applications does quantum physics have, specifically?

  • mustang19
  • · Replies 7 ·
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7

Graduate What is the Linear Variation Method in Molecular Quantum Mechanics?

  • Morten
  • · Replies 1 ·
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1

Graduate Can a cross product be defined between two Hilbert space vectors?

  • DuckAmuck
  • · Replies 1 ·
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1

Undergrad Single electron ....two slits?

  • tom.mulloy
  • · Replies 5 ·
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5

Graduate Criticize diagram of delayed choice quantum eraser

  • Strilanc
  • · Replies 4 ·
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4

Graduate Oppenheimer's QM lecture notes

  • mach4
  • · Replies 8 ·
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8

Graduate Slater determinants in Configuration Interaction

  • saleheen
  • · Replies 1 ·
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1

Graduate Wave-function solution under Galilean transformations

  • Happiness
  • · Replies 3 ·
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3

Graduate Entanglement and Some Unanswered Questions

  • Neandethal00
  • · Replies 8 ·
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8

Undergrad Whats so amazing about the wave equation?

  • toesockshoe
  • · Replies 1 ·
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1

Graduate Why Does ½ Factor in HF Expectation Value?

  • Morten
  • · Replies 6 ·
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6

Graduate Electron ejected in Photoelectric effect

  • Neutroniclad
  • · Replies 27 ·
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27

Undergrad Projective measurement and correlations: examples

  • kaje
  • · Replies 3 ·
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3

Graduate Non-technical description of "superposition"

  • Negatratoron
  • · Replies 10 ·
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10

Graduate Question about the wave function of a travelling wave

  • Jeremy1986
  • · Replies 3 ·
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3