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Physics Stack Exchange users whose comments are worth studying include Lubos Motl and Ron Maimon (now at http://www.quora.com/Ron-Maimon and http://www.physicsoverflow.org/user/Ron+Maimon). Also see http://arxiv.org/abs/hep-ph/0207124 for a review of physics since the standard model.


Oct
3
comment How to determine the amount of light energy (photons) being released from an incandescent light bulb?
Well, it was either this, or just say, "there is no effect, the quarks aren't involved in the emission of light". As I tried to convey with the fly taking off from the balloon containing the marbles, there will be some indirect reaction back on the nucleus, as part of the recoil from emitting the photon, but it will be minuscule.
Oct
2
comment How does the Super-Kamiokande experiment falsify SU(5)?
Some comments on your points 1-4. 1. The simplest way to break the SU(5) symmetry is with a second Higgs field, in addition to the one which subsequently breaks SU(2)xU(1) to U(1). 2. Yes. 3. Quarks and leptons would still be fundamental, but they are classified into larger and fewer multiplets (5- and 10-dimensional reps of SU(5)) than in the SM. 4. The new ingredient is that a quark can become a lepton (or vice versa), thanks to the extra SU(5) bosons (X and Y particles, or leptoquark bosons). It's rare because they are heavy. The proton disintegrates e.g. into a pion and a lepton.
Sep
30
comment Way to become a physicist
You might do better on Quora with this question, because there are so many Indian users there.
Sep
30
comment What happens to the amplituhedron in a non-peturbative context?
@Vibert Perhaps it would be the scattering of the tensionless strings? But both N=4 SYM, and ABJM, have Grassmannian descriptions, so it makes sense that (2,0) would, too.
Sep
27
comment What happens to the amplituhedron in a non-peturbative context?
You can define twistor space for six space-time dimensions e.g. arxiv.org/abs/1111.2539, and there are many connections between 4d, 5d, and 6d SUSY QFTs, e.g. see Witten's work on Khovanov homology. So point taken, but there's reason to believe it's possible.
Sep
25
comment What happens to the amplituhedron in a non-peturbative context?
But that's the theory of scattering inside an M5-brane - how the excitations of the M5-brane interact. Scattering of M5-branes from each other, in some more general space-time background, is a different story, and ties into the general problem of how to understand string theory in the most general way possible.
Sep
25
comment What happens to the amplituhedron in a non-peturbative context?
Regarding the M5-branes... It seems plausible that the worldvolume theory of a stack of M5-branes - which will be some version of (2,0) theory - has an amplituhedron, simply because (2,0) is another conformal, maximal-susy theory.
Sep
25
answered How to determine the amount of light energy (photons) being released from an incandescent light bulb?
Sep
25
comment How to determine the amount of light energy (photons) being released from an incandescent light bulb?
But in a solid... I'm guessing most of the recoil energy will be carried away by conduction electrons somehow. And I'm quite unclear on how to conceive of the mechanical coupling between (nuclei+electron shells) and the Fermi gas of conduction electrons.
Sep
25
comment How to determine the amount of light energy (photons) being released from an incandescent light bulb?
In the case of a free atom, conservation of momentum tells you that there will be recoil from emission of the photon, and presumably there will be some sort of very minute "quantum ringing" of the ground-state atom around its center of mass.
Sep
25
comment How to determine the amount of light energy (photons) being released from an incandescent light bulb?
True. But if I do write the perfect answer to this question, I will probably discuss the simpler case of a free atom, as in a gas, before moving on to the harder case of atoms in a solid.
Sep
25
comment How to determine the amount of light energy (photons) being released from an incandescent light bulb?
The central question seems to be, what is the recoil of an atom when one of its electrons emits a photon, and in particular how does this recoil affect the nucleus. Then to ask further about the quarks, is to ask how quarks respond when the nucleons that contain them are shaken.
Sep
25
comment How to determine the amount of light energy (photons) being released from an incandescent light bulb?
Process 1-3 happens in light bulbs. True, we don't normally analyze light bulbs on the Planck scale. However, I will try to answer the question.
Sep
20
comment Quantum Number of a Tennis Ball
Presumably one is supposed to think of the ball as a point particle with the mass of a tennis ball, rather than as an extended object with 10^23 internal degrees of freedom.
Sep
19
comment Equation of everything
Raisa, if you read this, please contact me at the email in my profile. I will talk to the moderators and try to get your suspension cancelled.
Sep
18
comment Equation of everything
OK, I'm returning to this question to see if there was any feedback from the poster - and she's been "suspended for low quality contributions", for a year?! What the?? Where can I protest about this?
Sep
18
revised Equation of everything
more on chiral fermions
Sep
18
answered Equation of everything
Sep
13
comment How does entanglement work independent of time?
I have not tried to understand the experiment, but have just skimmed this commentary scienceblogs.com/principles/2012/10/05/… ... The author says yes, it is entanglement swapping. He also says it could be viewed as "a quantum teleportation kind of thing, teleporting a state into the future via a chain of entanglement"... which might be what was discussed at physics.stackexchange.com/questions/3357/…
Sep
9
answered How widespread is the meme “QM is counterintuitive” in academic physics?