User Tobias Kienzler

105 votes

11 answers

16k views

Is there something similar to Noether's theorem for discrete symmetries?

asked Aug 24, 2010 at 8:21

53 votes

9 answers

7k views

Is a "third quantization" possible?

quantum-field-theory quantization second-quantization

asked Nov 12, 2010 at 8:57

49 votes

5 answers

3k views

Is the world $C^\infty$?

quantum-field-theory analyticity

asked Nov 26, 2010 at 11:24

43 votes

17 answers

5k views

Why does one experience a short pull in the wrong direction when a vehicle stops?

newtonian-mechanics jerk

asked Nov 12, 2010 at 10:01

19 votes

1 answer

5k views

What is the definition of how to count degrees of freedom?

definition degrees-of-freedom

asked Apr 19, 2011 at 7:41

19 votes

2 answers

378 views

Can symmetry generators be used for quantization?

quantum-field-theory mathematical-physics symmetry group-theory quantization

asked Sep 15, 2011 at 7:15

18 votes

4 answers

5k views

If all conserved quantities of a system are known, can they be explained by symmetries?

mathematical-physics symmetry noethers-theorem conservation-laws integrals-of-motion

asked Apr 14, 2011 at 8:35

16 votes

2 answers

953 views

What colour is an electron?

electromagnetic-radiation quantum-electrodynamics non-linear-optics

asked Apr 19, 2017 at 11:45

14 votes

2 answers

1k views

Is a neutron star basically an isotope?

neutrons neutron-stars isotopes

asked Sep 13, 2015 at 19:35

14 votes

3 answers

768 views

Are there models/simulations of antigravitational antimatter-galaxies?

gravity simulations antimatter galaxies models

asked Nov 4, 2013 at 13:04

12 votes

3 answers

1k views

Does the concept of a "momenton" make sense?

quantum-field-theory operators momentum quantum-gravity second-quantization

asked Nov 22, 2020 at 8:55

10 votes

1 answer

1k views

Imaginary time is to inverse temperature what imaginary entropy is to ...?

time temperature entropy complex-numbers wick-rotation

asked Oct 25, 2014 at 19:40

7 votes

2 answers

565 views

Why does $\mathcal L = -\frac14 F^{\mu\nu} F_{\mu\nu}$ imply Photons are massless?

particle-physics photons group-theory group-representations

asked Jan 4, 2013 at 17:19

6 votes

2 answers

398 views

Is Quantum Coulomb still singular?

quantum-mechanics electromagnetism charge singularities coulombs-law

asked Sep 9, 2015 at 18:27

6 votes

1 answer

1k views

How to correctly calculate the colour of the sky?

optics electromagnetic-radiation scattering atmospheric-science sun

asked Jul 13, 2016 at 6:55

5 votes

2 answers

6k views

How to measure Entropy?

entropy measurements

asked Aug 2, 2014 at 10:01

4 votes

1 answer

108 views

A nice overview (and maybe derivation) of the Poincaré transformations of the Vector Spherical Harmonics

research-level specific-reference group-representations poincare-symmetry spherical-harmonics

asked Feb 28, 2012 at 13:13

3 votes

1 answer

1k views

Is the Gibbs-Duhem equation always valid?

thermodynamics potential

asked Oct 8, 2014 at 9:41

2 votes

1 answer

59 views

What is an easily achievable way to have a fluid crawl or dry at ca. 30 mm/week = ca. 0.05 µm/s?

time measurements flow

asked May 5, 2021 at 9:30

2 votes

1 answer

147 views

Can a laser-pumped laser cavity be laser-cooled by its pumping laser (and pump its pumping laser in return)? Is remote-cooling possible outside a lab?

laser doppler-effect cooling

asked Oct 1, 2021 at 10:42

1 vote

2 answers

189 views

Does time pass fastest in isolated, resting space?

general-relativity time vacuum

asked Oct 9, 2013 at 11:59

0 votes

1 answer

152 views

How linearly additive are the x-ray mass attenuation coefficients for molecules?

absorption x-rays attenuation

asked Aug 5, 2018 at 9:24

0 votes

1 answer

41 views

What is/are the canonical notation(s) for multi-particle states? What are they mathematically?

quantum-mechanics hilbert-space notation quantum-states

asked Oct 13, 2021 at 14:15

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23 Questions

Is there something similar to Noether's theorem for discrete symmetries?

Is a "third quantization" possible?

Is the world $C^\infty$?

Why does one experience a short pull in the wrong direction when a vehicle stops?

What is the definition of how to count degrees of freedom?

Can symmetry generators be used for quantization?

If all conserved quantities of a system are known, can they be explained by symmetries?

What colour is an electron?

Is a neutron star basically an isotope?

Are there models/simulations of antigravitational antimatter-galaxies?

Does the concept of a "momenton" make sense?

Imaginary time is to inverse temperature what imaginary entropy is to ...?

Why does $\mathcal L = -\frac14 F^{\mu\nu} F_{\mu\nu}$ imply Photons are massless?

Is Quantum Coulomb still singular?

How to correctly calculate the colour of the sky?

How to measure Entropy?

A nice overview (and maybe derivation) of the Poincaré transformations of the Vector Spherical Harmonics

Is the Gibbs-Duhem equation always valid?

What is an easily achievable way to have a fluid crawl or dry at ca. 30 mm/week = ca. 0.05 µm/s?

Can a laser-pumped laser cavity be laser-cooled by its pumping laser (and pump its pumping laser in return)? Is remote-cooling possible outside a lab?

Does time pass fastest in isolated, resting space?

How linearly additive are the x-ray mass attenuation coefficients for molecules?

What is/are the canonical notation(s) for multi-particle states? What are they mathematically?