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

Undergrad Is Maxwell's electromagnetism an effective (field) theory?

  • Husserliana97
  • · Replies 3 ·
Replies
3

Undergrad Why can’t photons “pile up” to eject an electron?

  • Kostik
  • · Replies 3 ·
Replies
3

Undergrad The Extended Wigner's Friend Scenarios

  • ChadGPT
  • · Replies 42 ·
2
Replies
42

Graduate I have some naive questions about the Reeh-Schlieder theorem

  • antaris
  • · Replies 1 ·
Replies
1

Undergrad Do ensemble-based predictions truly describe real finite systems?

  • syed
  • · Replies 4 ·
Replies
4

Undergrad How strong is the justification for low probability extreme thermal fluctuations?

  • syed
  • · Replies 6 ·
Replies
6

High School Is a table levitating possible, even at a minuscule probability?

  • syed
  • · Replies 32 ·
2
Replies
32

Undergrad Energy*time uncertainty for particle decay

  • jjson775
  • · Replies 27 ·
Replies
27

Undergrad Commutation of operators for particle in a box

  • hokhani
  • · Replies 16 ·
Replies
16

High School A Time Crystal Visible to the Human Eye

  • jedishrfu
  • · Replies 5 ·
Replies
5

Undergrad Quantum Entanglement and Synchronization

  • James Hasty
  • · Replies 6 ·
Replies
6

Undergrad Electron energy in atoms

  • hokhani
  • · Replies 10 ·
Replies
10

Graduate What is the connection between entanglement and the no-cloning theorem?

  • mister robi
  • · Replies 1 ·
Replies
1

High School Two/three photon absorption chemical substance producing photons for electricity generation

  • Cybersoya
  • · Replies 0 ·
Replies
0

High School Quantum entanglement

  • Mark Szumilewicz
  • · Replies 1 ·
Replies
1

Undergrad Quantum behaviour of an electron around a positively charged sphere

  • hokhani
  • · Replies 18 ·
Replies
18

Undergrad Visual depiction of atomic orbitals

  • hokhani
  • · Replies 12 ·
Replies
12

Undergrad Bloch Sphere generalization for more than one qubit

  • pervect
  • · Replies 4 ·
Replies
4

Undergrad Probabalistic determination Photon Entaglement

  • RobbyQ
  • · Replies 6 ·
Replies
6

Undergrad Commutator of x and p in quantum mechanics

  • rbphysics
  • · Replies 4 ·
Replies
4

Graduate Physical properties of the vacuum in GR vs. QFT

  • Iskandarani
  • · Replies 15 ·
Replies
15

Graduate Confusion about creation/annihilation operators with interaction

  • gasgas
  • · Replies 1 ·
Replies
1

High School Schrödinger's cat question

  • leonid.ge
  • · Replies 6 ·
Replies
6

Undergrad How can quantum physics contribute to medical physics?

  • juliocastro
  • · Replies 1 ·
Replies
1

Graduate Eigenstates of the Klein Gordon Field Operator

  • Jonathan Apps
  • · Replies 8 ·
Replies
8

Undergrad Direction of time-evolution in time reversed wave functions

  • hokhani
  • · Replies 12 ·
Replies
12

Graduate Angular momentum uncertainty principle and the particle on a ring

  • physical_chemist
  • · Replies 5 ·
Replies
5

Graduate Effects of perception

  • edmund cavendish
  • · Replies 4 ·
Replies
4

Undergrad Emission probability in blackbody spectrum derivation

  • Swamp Thing
  • · Replies 1 ·
Replies
1

Undergrad Feynman's derivation of average square distance variation in Brownian motion

  • l4teLearner
  • · Replies 3 ·
Replies
3

Undergrad Phase and group velocity for the wave function

  • hokhani
  • · Replies 14 ·
Replies
14

Undergrad Validity of identical eigenfunction of commutating operators

  • hokhani
  • · Replies 12 ·
Replies
12

Undergrad Action of an Hermitian unitary operator member of SU(2)

  • cianfa72
  • · Replies 15 ·
Replies
15

Undergrad About concept of wave-particle duality

  • south
  • · Replies 11 ·
Replies
11

Undergrad Hydrogen 21 cm line time?

  • jv11
  • · Replies 5 ·
Replies
5

Undergrad I would like some assistance working with commutators

  • hmparticle9
  • · Replies 1 ·
Replies
1

Undergrad Shape of wave function (probability distribution) of a single photon

  • J O Linton
  • · Replies 16 ·
Replies
16

Undergrad Would gravitons theoretically act like photons?

  • Josiah
  • · Replies 18 ·
Replies
18

Graduate Baryon CP Violation Observed at CERN

  • PeterDonis
  • · Replies 7 ·
Replies
7

Graduate Geometry Topology and Physics: Nakahara, Chapt. 1: Weyl Ordering

  • XiYi
  • · Replies 1 ·
Replies
1

High School Energy-time uncertainty relation for a volume and macroscopic objects?

  • Aidyan
  • · Replies 2 ·
Replies
2

Graduate Why must operators map Hilbert space vectors to Hilbert space vectors?

  • gaiussheh
  • · Replies 59 ·
2
Replies
59

High School The wave function of the electron doesn't collapse when passing through air?

  • cosmanino2050
  • · Replies 9 ·
Replies
9

Undergrad New book on algebraic quantum physics

  • A. Neumaier
  • · Replies 6 ·
Replies
6

Undergrad Why quarter-wave plates don't distinguish H/V from D/A polarization mixtures

  • Erik Ayer
  • · Replies 7 ·
Replies
7

Undergrad Density matrix representation of a density operator

  • cianfa72
  • · Replies 8 ·
Replies
8

Undergrad How to understand quantum computers?

  • Alex Notman
  • · Replies 9 ·
Replies
9

Undergrad Bose-Einstein statistics and the Photon

  • redtree
  • · Replies 1 ·
Replies
1

Graduate Explicit construction of Galilean-invariant space

  • Adgorn
  • · Replies 1 ·
Replies
1

Undergrad Addition of angular momenta

  • alebruna
  • · Replies 1 ·
Replies
1

Undergrad Quantum decoherence vs. measurement process

  • timmdeeg
  • · Replies 3 ·
Replies
3

Undergrad Quantum eraser experiment

  • J O Linton
  • · Replies 3 ·
Replies
3

Graduate Can scattering experiment be used to determine location and momentum of an electron?

  • sumitgarg1
  • · Replies 2 ·
Replies
2

Insights Quantum Computing for Beginners

  • Bob Walance
  • · Replies 19 ·
Replies
19

Undergrad Bob and Alice with a Bell pair

  • Heidi
  • · Replies 3 ·
Replies
3

High School Gravitons vs photons: Does the size of the atom make any difference?

  • Josiah
  • · Replies 3 ·
Replies
3

Undergrad What's the deal with instantons?

  • pines-demon
  • · Replies 1 ·
Replies
1

Undergrad How to derive orbital angular momentum of spins in quantum mechanics?

  • geelpheels
  • · Replies 2 ·
Replies
2

Undergrad Deriving Bogoliubov transformations correctly

  • pines-demon
  • · Replies 12 ·
Replies
12

Undergrad Dirac's 1972 Boston talk on Projective geometry in quantum mechanics

  • grzz
  • · Replies 7 ·
Replies
7

High School Feynman QED Questions

  • photonographer
  • · Replies 15 ·
Replies
15

Graduate Scattering cross section between charged particle and magnetic moment

  • dark_matter_is_neat
  • · Replies 1 ·
Replies
1

Undergrad More information on the momentum eigenstate in the position basis

  • hmparticle9
  • · Replies 1 ·
Replies
1

Undergrad Measurement problem - will this work?

  • Gary Venter
  • · Replies 4 ·
Replies
4

Undergrad Quantum wavelength in gravitation

  • south
  • · Replies 6 ·
Replies
6

Graduate Pauli–Villars ghost fields?

  • pines-demon
  • · Replies 8 ·
Replies
8

Graduate Magnetic field produced by moving charge in operator form

  • dark_matter_is_neat
  • · Replies 14 ·
Replies
14

Undergrad Tensor products and simultaneous eigenstates

  • LightPhoton
  • · Replies 1 ·
Replies
1

Undergrad Molecular Quantum Computer Progress

  • Hornbein
  • · Replies 1 ·
Replies
1

Undergrad Coherence time for repeated spin measurements

  • aa2ll2
  • · Replies 9 ·
Replies
9

Graduate John Bell 1964 toy model for spin

  • jf117
  • · Replies 3 ·
Replies
3

High School Thought experiment: Beyond the slowest measurable speed?

  • CelestialAeon
  • · Replies 20 ·
Replies
20

Undergrad Black Hole Fermion Count

  • .Scott
  • · Replies 1 ·
Replies
1

Undergrad Free Schroedinger equation: time separation

  • chartery
  • · Replies 3 ·
Replies
3

Undergrad I would like an explanation of these extra energy states

  • hmparticle9
  • · Replies 3 ·
Replies
3

Graduate Does Causality in QFT Require Commuting Field Operators Outside the Light Cone?

  • rbphysics
  • · Replies 18 ·
Replies
18

High School Why NIST omits series limits from hydrogen strong line listings

  • James Kahn
  • · Replies 4 ·
Replies
4

Graduate Time Reversal and initial conditions

  • hokhani
  • · Replies 8 ·
Replies
8

Undergrad Choice of basis in BB84 protocol

  • lys04
  • · Replies 2 ·
Replies
2

Undergrad Time dependent Hamiltonian and energy

  • hokhani
  • · Replies 2 ·
Replies
2

Undergrad I want to understand how the transmission coefficient is obtained

  • hmparticle9
  • · Replies 3 ·
Replies
3

Undergrad Postulate of only time dependence on |ψ⟩

  • LightPhoton
  • · Replies 2 ·
Replies
2

Undergrad When does operator A(r)Ψ(r) equal ⟨r|Â|Ψ⟩?

  • LightPhoton
  • · Replies 2 ·
Replies
2

Undergrad A short attenuated laser pulse, LIGO, and a fast detector

  • Spinnor
  • · Replies 1 ·
Replies
1

Undergrad Using a single particle as quantum computer

  • danielhaish
  • · Replies 8 ·
Replies
8

High School Bell's Inequalities and the issue of non-locality

  • Tolga T
  • · Replies 59 ·
2
Replies
59

Undergrad Mean values of observables

  • Vyurok
  • · Replies 2 ·
Replies
2

Graduate Bell's inequality and experiment

  • leonid.ge
  • · Replies 8 ·
Replies
8

Undergrad States and observables in quantum mechanics

  • Vyurok
  • · Replies 5 ·
Replies
5

Undergrad Passing information faster than speed of light

  • leonid.ge
  • · Replies 20 ·
Replies
20

Undergrad Energy and momentum in quantum mechanics

  • Vyurok
  • · Replies 8 ·
Replies
8

High School Double-slit with movable detector screen

  • Physwa
  • · Replies 15 ·
Replies
15

Undergrad QED replacing photon field with current in 3-point function

  • handrea2009
  • · Replies 1 ·
Replies
1

Undergrad Expansion of position kets in terms of angular momentum

  • hokhani
  • · Replies 5 ·
Replies
5

High School About the nature of the Newtonian gravitational formula

  • south
  • · Replies 7 ·
Replies
7

Graduate Numerical implementation of creation and annhilation operators in the SSH model

  • JangMilad
  • · Replies 0 ·
Replies
0

Graduate 2nd Quantization states

  • MaestroBach
  • · Replies 1 ·
Replies
1

Undergrad Heisenberg uncertainty principle and the canonical momentum operator

  • wnvl2
  • · Replies 32 ·
2
Replies
32

High School Heisenberg Uncertainty Principle question

  • skeptic2
  • · Replies 9 ·
Replies
9

Graduate Coleman: "Spin is a concept that applies only to particles with mass"

  • Kostik
  • · Replies 11 ·
Replies
11