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Quantum Interpretations and Foundations

Seeking clarity on the physical definition of an observer
1.3K threads
Seeking clarity on the physical definition of an observer
Undergrad Spin operator and spin quantum number give different values, why?
  • 43arcsec
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12
Graduate What is the biggest problem to be solved in Quantum Physics in 2023?
  • ThiagoMNobrega
  • · Replies 48 ·
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48
High School Bell inequality test without polarisation?
  • lukephysics
  • · Replies 8 ·
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8
Undergrad Questions about Grover's algorithm for quantum searches
  • LLSM
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6
Graduate What is a spatial wavefunction in QFT?
  • George Wu
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4
Undergrad Average magnetic moment of atom in magnetic field ##B##
  • ergospherical
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Undergrad Quantum decoherence and the emergence of space/time and gravity
  • shunyadragonvv
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Graduate A question about entanglement swapping
  • Heidi
  • · Replies 4 ·
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4
Undergrad Photoelectric effect: Saturation voltage
  • mgcgian
  • · Replies 4 ·
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4
Undergrad Is the Archimedes Experiment a groundbreaking test of the Casimir Effect?
  • hyksos
  • · Replies 10 ·
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10
Undergrad Quantum Mechanics as a Probabilistic forecast of reality
  • physwiz222
  • · Replies 21 ·
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21
Undergrad Generation of polarization-squeezed beams
  • James2018
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2
Graduate Do Time-ordering and Time Integrals commute? Peskin(4.22)(4.31)(4.44)
  • George Wu
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3
Undergrad Hidden phase in polarization tests of Bell's inequality?
  • Leureka
  • · Replies 49 ·
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Undergrad Are Nicolas Gisin's Intuitionist Mathematics Theories Compatible with SR and GR?
  • lektroon
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7
Undergrad Biphoton: Existence of layered or multiple entanglements
  • Revolucien
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5
Undergrad Understanding Scattered Radiation in Photon Beams
  • eneacasucci
  • · Replies 8 ·
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8
Undergrad Understanding the Equations of Motion for the Dirac Lagrangian
  • JohnH
  • · Replies 1 ·
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1
Undergrad Showing that operators follow SU(2) algebra
  • graviton_10
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Undergrad Mass of Electron & Flipping Frequency: Leonard Susskind Explains
  • Sagittarius A-Star
  • · Replies 1 ·
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Undergrad The Potential of Back-to-Back Photons: an Experiment
  • Grelbr42
  • · Replies 4 ·
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4
Undergrad Noise Proportional to Square Root of Illumination: Need Formula Help
  • Joseffina
  • · Replies 0 ·
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0
Undergrad Do black holes destroy quantum states?
  • Halc
  • · Replies 4 ·
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4
Graduate How can gauge fields be associated with real particles?
  • Pradyuman
  • · Replies 13 ·
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13
Undergrad Quantum Entanglement and Parallel Worlds/Existence
  • giodude
  • · Replies 7 ·
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7
Undergrad Principles of Quantum Mechanics - Hans C. Ohanian - 0137127952
  • hachi44
  • · Replies 3 ·
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3
Graduate Bound states of an electron trapped in a dipole field
  • reterty
  • · Replies 1 ·
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1
High School Entanglement inside a black hole
  • Kostik
  • · Replies 14 ·
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14
Undergrad ##Tr([Q,P])## and Ballentine Problem 6.3
  • EE18
  • · Replies 31 ·
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High School Are Photons Real? New Study Challenges Assumptions
  • log0
  • · Replies 17 ·
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17
High School What exactly is spin? Does the standard model work without spin?
  • DomDominate
  • · Replies 27 ·
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27
High School Quantum Computers and their special properties?
  • LightningInAJar
  • · Replies 4 ·
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4
Graduate Why Unitary Evolution? QM Justification Ideas
  • LittleSchwinger
  • · Replies 63 ·
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Graduate Main Theorem of Renormalization, but in physicist-speak
  • AndreasC
  • · Replies 10 ·
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10
Undergrad Uncovering the Mystery of Kallen-Lehmann Spectral Representation
  • AndreasC
  • · Replies 15 ·
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15
Undergrad Dirac Notation for Operators: Ambiguity in Expectation Values?
  • dyn
  • · Replies 5 ·
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5
High School The Mystery of Excited Electrons: Are They Moving Away from the Nucleus?
  • Mustafa Bayram
  • · Replies 2 ·
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2
Undergrad Ways of measuring open quantum systems
  • Couchyam
  • · Replies 1 ·
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1
Graduate Can entanglement be detected in a single Bell pair?
  • DrChinese
  • · Replies 1 ·
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Undergrad Necessity of the field viewpoint
  • simonjech
  • · Replies 5 ·
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5
Undergrad Noether currents for a complex scalar field and a Fermion field
  • Sandglass
  • · Replies 3 ·
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3
Undergrad How to add time variation to a Schrodinger operator?
  • snoopies622
  • · Replies 11 ·
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11
Undergrad Propagator of massless Weyl field
  • Siupa
  • · Replies 10 ·
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10
Graduate How to measure the two-photon detuning in 3-level system?
  • wangvivi
  • · Replies 2 ·
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Undergrad Translating the harmonic oscillator
  • ergospherical
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2
High School Quantum Entanglement & Hybridization
  • LilandB
  • · Replies 7 ·
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7
Undergrad Finding Eigenvectors of 2-state system
  • Kekeedme
  • · Replies 7 ·
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7
Graduate Numerical method to Lippman-Schwinger equation
  • HadronPhysics
  • · Replies 1 ·
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1
High School Atom energy band formation and electron allotment
  • Clueless123
  • · Replies 5 ·
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5
Undergrad Rewriting of Gibbs Free Energy in Peksin (Equations 13.35/13.36)
  • thatboi
  • · Replies 12 ·
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12
Undergrad Classic 'Double-Slit' Experiment Using Time Instead of Space
  • sbrothy
  • · Replies 3 ·
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3
High School Quantum entanglement and simultaneity
  • Freixas
  • · Replies 4 ·
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4
High School Is it possible to measure both position and momentum simultaneously?
  • Clueless123
  • · Replies 13 ·
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Undergrad Does a particle's mass fluctuate.
  • maximdogger
  • · Replies 10 ·
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10
Undergrad Symmetry and two electron wave function
  • hokhani
  • · Replies 7 ·
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7
Graduate Wave-packet in configuration space
  • Pradyuman
  • · Replies 1 ·
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1
Graduate What’s the meaning of decay rate in optical Bloch equations?
  • wangvivi
  • · Replies 1 ·
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1
Graduate Relation between the density matrix and the annihilation operator
  • richard_andy
  • · Replies 0 ·
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0
Undergrad Fourier Transform of Photon Emission Hamiltonian
  • thatboi
  • · Replies 4 ·
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4
Undergrad Identity involving exponential of operators
  • thatboi
  • · Replies 2 ·
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2
Undergrad Superposition of different spins
  • Isaac0427
  • · Replies 15 ·
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15
Undergrad Why is there an additional prefactor in equation (12.52) of Peskin's QFT book?
  • thatboi
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Undergrad Where is the mass of a particle located?
  • HansH
  • · Replies 21 ·
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21
Undergrad Weakly interacting electrons in an atom
  • Isaac0427
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Undergrad Black Hole Information path described in new article
  • .Scott
  • · Replies 0 ·
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0
Undergrad Non-Commutation Property and its Relation to the Real World
  • expos4ever
  • · Replies 19 ·
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High School Quantum entanglement and hidden variables
  • PainterGuy
  • · Replies 7 ·
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7
High School What do these wavenumbers correspond to in Raman spectroscopy?
  • Lotto
  • · Replies 5 ·
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5
Undergrad Ballentine Equation 5.13 on conservation of momentum
  • EE18
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3
Graduate Von Neumann's uniqueness theorem (CCR representations)
  • Heidi
  • · Replies 9 ·
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9
Undergrad Does an electron have a quantum phase frequency?
  • H_A_Landman
  • · Replies 36 ·
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Undergrad Prefactor in Canonical Quantization of Scalar Field
  • thatboi
  • · Replies 4 ·
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4
Undergrad Momentum eigenfunctions in an infinite well
  • dyn
  • · Replies 31 ·
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Undergrad Potential energy of spin anti-alignment
  • Sky Darmos
  • · Replies 14 ·
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14
High School Does anything happen in the quantum world?
  • DiamondHead
  • · Replies 12 ·
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12
Graduate Quantum analog of Boltzmann entropy?
  • Demystifier
  • · Replies 43 ·
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High School How to show that particle spin includes angular momentum?
  • snoopies622
  • · Replies 14 ·
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14
Graduate Momentum operator -- Why do we use the plane wave solution?
  • zb23
  • · Replies 8 ·
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8
Undergrad QED Renormalization Counterterm Confusion
  • thatboi
  • · Replies 6 ·
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6
High School What are the energy eigenvalues of a harmonic oscillator?
  • Lotto
  • · Replies 2 ·
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2
Undergrad Interaction of EM radiation with Glass
  • Jimmy87
  • · Replies 14 ·
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14
Undergrad Mach-Zehnder interferometer, but with an entangled beam?
  • Marilyn67
  • · Replies 33 ·
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Undergrad What is the relation between the Dirac equation and QED?
  • thaiqi
  • · Replies 7 ·
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7
Undergrad What happens when circular polarization meets a diagonal polarizer?
  • fluidfcs
  • · Replies 20 ·
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20
Undergrad Repeated measurements on a quantum system interacting with other quantum systems
  • accdd
  • · Replies 3 ·
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3
Graduate How to derive Quantum Mechanics in curved physical space?
  • victorvmotti
  • · Replies 6 ·
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6
High School Is a Spin 2 Particle the Key to Understanding Gravitation in Quantum Mechanics?
  • Omega0
  • · Replies 26 ·
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26
Graduate Multiparticle Relativistic Quantum Mechanics in an external potential
  • curious_mind
  • · Replies 22 ·
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22
Undergrad Can Quantum Effects Prevent Reaching Absolute Zero?
  • nomadreid
  • · Replies 3 ·
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3
Undergrad Measurement of a superposition and Born's rule
  • mbond
  • · Replies 22 ·
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22
Undergrad What is the true nature of microscopic particles when not interacting?
  • Suryabarta Saha
  • · Replies 4 ·
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4
Graduate Symmetries of particle interacting with external fields (Ballentine)
  • EE18
  • · Replies 5 ·
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5
Graduate Ballentine on construction of the (Galilean) symmetry generators
  • EE18
  • · Replies 17 ·
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17
Undergrad Dot product of two vector operators in unusual coordinates
  • Old Person
  • · Replies 14 ·
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14
Undergrad Schwinger-Dyson equations derivation
  • simonjech
  • · Replies 3 ·
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3
Graduate Learning DFT: Inhomogeneous Electron Gas (Hohenberg) Question
  • yosty222
  • · Replies 1 ·
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Undergrad Finding ##\partial^\mu\phi## for a squeezed state in QFT
  • Sciencemaster
  • · Replies 2 ·
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2
Undergrad Free particle probability distribution
  • zekise
  • · Replies 22 ·
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22
Undergrad States of equal energy are equally probable
  • msumm21
  • · Replies 29 ·
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29
Undergrad Diffraction of Matter: Examining Bohr's Theory
  • Mustafa Bayram
  • · Replies 6 ·
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6