Hottest Questions Today

0

votes

2

answers

12

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Why is $\langle c \cdot f|g\rangle=c^*\langle f|g\rangle$?

answered 23 mins ago Aaron Stevens 4,744

7

votes

4

answers

697

views

What is the experimental evidence that the nucleons are made up of three quarks?

particle-physics nuclear-physics quantum-chromodynamics quarks protons

answered 2 hours ago JEB 4,824

71

votes

14

answers

7k

views

Simple check for the global shape of the Earth

earth education

modified 7 hours ago pela 7,137

1

vote

1

answer

17

views

Physical reasoning behind hearing a single shock

waves pressure acoustics machs-principle

modified 1 hour ago Al Nejati 1,689

4

votes

3

answers

199

views

Infinitely many conserved currents in any QFT?

electromagnetism conservation-laws field-theory gauge-theory noethers-theorem

modified 2 mins ago Qmechanic♦ 98k

0

votes

0

answers

11

views

$\dot{W}_{lost}$ due to irreversible processes in the condenser of a refrigeration system

homework-and-exercises thermodynamics entropy

modified 43 mins ago Jay 1

-2

votes

1

answer

33

views

Why photons do not have mass?

photons mass relativity

modified 2 hours ago Emilio Pisanty 79.1k

0

votes

0

answers

24

views

Confusion with entropy change associated with thermal reservoirs in an isobaric process

homework-and-exercises thermodynamics entropy

modified 2 hours ago Partha Sarker 1

0

votes

1

answer

22

views

Forced oscillating spring-mass system terms

classical-mechanics spring

modified 1 hour ago Aaron Stevens 4,744

0

votes

0

answers

14

views

Fermat principle

general-relativity optics differential-geometry

asked 3 hours ago Amit Jha 21

-2

votes

0

answers

25

views

Could the Phenomenon of Particle Half-Life be a Manifestation of Wave Interference?

double-slit-experiment wave-particle-duality half-life

modified 3 hours ago Thor 56

0

votes

0

answers

16

views

Dirac field local observables

homework-and-exercises quantum-field-theory

asked 4 hours ago Charlie 367

2

votes

0

answers

32

views

Non-zero Hamiltonian matrix elements in a generic QFT

quantum-field-theory hilbert-space

modified 2 hours ago mavzolej 752

-2

votes

0

answers

15

views

CMB signal wavelength, amplitude and frequency

cosmic-microwave-background

asked 4 hours ago marcstewart 1

0

votes

0

answers

26

views

Can Eugene Wigner's “consciousness causes collapse” interpretation of quantum mechanics be made lorentz invariant?

quantum-mechanics lorentz-symmetry

asked 4 hours ago Nov 137

1

vote

1

answer

40

views

Commutator expectation value in Quantum mechanics

quantum-mechanics commutator

answered 7 hours ago DanielC 1,568

0

votes

0

answers

11

views

Continuity equation is guage invariant for a charged particle in electromagnetic field

quantum-mechanics gauge

asked 5 hours ago Dhananjay Mishra 1

0

votes

1

answer

39

views

How far under the sea is sunlight at 50% of surface level?

visible-light

answered 7 hours ago notevenwrong 46

-1

votes

0

answers

15

views

Two in-line double-slit experiment

quantum-mechanics double-slit-experiment

asked 5 hours ago John Petrovic 62

0

votes

2

answers

51

views

Can you anti-dot? (9-22 from Marion Thorton)

energy kinematics vectors collision

answered 8 hours ago RogerJBarlow 2,264

0

votes

0

answers

13

views

Fluctuating Thermodynamic Properties in an ensemble

thermodynamics

asked 6 hours ago user1679198 1

0

votes

4

answers

96

views

Symmetry of a tensor

general-relativity metric-tensor tensor-calculus relativity

modified 6 hours ago Stijn B. 461

0

votes

0

answers

19

views

How to calculate the time to uniformly heat an object by natural convection?

thermodynamics material-science

asked 7 hours ago user190081 459

0

votes

0

answers

21

views

Can two semi-infinite plane waves undergo perfectly constructive interference?

electromagnetic-radiation electric-fields laser

asked 8 hours ago Riley Jacob 111

0

votes

0

answers

29

views

What are the units for state vectors in QM? [on hold]

quantum-mechanics hilbert-space units dimensional-analysis

modified 8 hours ago Qmechanic♦ 98k

0

votes

2

answers

34

views

what exactly is a hyperfine level as mentioned in the definition of a second?

hyperfine-structure

answered 8 hours ago Maury Markowitz 2,031

8

votes

5

answers

2k

views

Why do we have to dump the extra entropy created in a heat engine?

thermodynamics work entropy heat-engine

answered 16 hours ago Dmitry Grigoryev 2,303

2

votes

1

answer

31

views

2D CFT for a Senior Undergraduate

resource-recommendations conformal-field-theory education

answered 9 hours ago Joshuah Heath 1,324

1

vote

1

answer

19

views

Why does classical light (arbitrary mixtures of coherent states) always result in super-Poissonian statistics?

quantum-mechanics photons quantum-information quantum-optics

answered 7 hours ago glS 6,078

0

votes

0

answers

19

views

Is there any threat to the results of our effective field theories from unknown higher energy theories?

quantum-field-theory quantum-gravity effective-field-theory

asked 9 hours ago Hanguk 1

8

votes

4

answers

3k

views

What's the speed of light when viewed from the side? [on hold]

visible-light speed-of-light velocity inertial-frames relative-motion

modified 21 hours ago Lehs 297

0

votes

1

answer

28

views

Noob question about centripetal acceleration

newtonian-mechanics rotational-kinematics

answered 9 hours ago V.F. 9,212

2

votes

3

answers

55

views

Wave and relativity

special-relativity classical-mechanics energy waves mass-energy

answered 9 hours ago md2perpe 521

1

vote

1

answer

44

views

Tensors and the Klein-Gordon Equation

quantum-mechanics special-relativity tensor-calculus klein-gordon-equation

answered 8 hours ago Frederic Thomas 1,312

1

vote

1

answer

24

views

Orientation of momentum of a virtual photon

quantum-electrodynamics

modified 10 hours ago WAH 587

0

votes

0

answers

35

views

What is the longest sight line available on Earth's surface?

visible-light earth

asked 11 hours ago Behacad 101

1

vote

1

answer

25

views

Finding initial speed $v_0$ of a projectile given horizontal ranges measured at various launch angles

homework-and-exercises kinematics projectile

answered 10 hours ago S. McGrew 4,458

0

votes

2

answers

34

views

Quickly write a unitary transformation connecting two arbitrary states

quantum-mechanics unitarity

answered 11 hours ago Noiralef 3,332

1

vote

1

answer

25

views

The uncertainty of a toy car's measured average speed

measurements speed experimental-technique

modified 11 hours ago stewy0013 69

2

votes

2

answers

37

views

Gravitationally-induced slowing-down of the spreading of a wave packet

quantum-mechanics gravity

answered 1 hour ago Dan Yand 31

0

votes

1

answer

46

views

Event Horizon & Black Holes

homework-and-exercises visible-light black-holes event-horizon

answered 12 hours ago Árpád Szendrei 3,383

6

votes

0

answers

35

views

Entropy and equilibrium concepts at astronomic scales

gravity statistical-mechanics astrophysics entropy equilibrium

modified 12 hours ago Qmechanic♦ 98k

1

vote

0

answers

20

views

Does a disk galaxy wobble (galactic wobble)?

black-holes galaxies

asked 11 hours ago Incredible II 57

0

votes

0

answers

20

views

Hallwachs' Experiment: why zinc?

experimental-physics photoelectric-effect

asked 10 hours ago Jasper 578

2

votes

1

answer

32

views

Hooke's Law and Overstretched Springs

newtonian-mechanics material-science spring elasticity

modified 11 hours ago Chemomechanics 3,313

3

votes

2

answers

80

views

What is meant by unitary time evolution?

quantum-mechanics hilbert-space hamiltonian time-evolution unitarity

modified 14 hours ago Avantgarde 915

0

votes

1

answer

38

views

Is there any tool can reverse the direction of electrical current or electromagnetic field?

electromagnetism electric-circuits

modified 11 hours ago ahemmetter 2,680

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