355 reputation
17
bio website
location
age
visits member for 1 year, 9 months
seen Apr 7 at 22:29

Oct
14
awarded  Critic
Oct
14
comment Why do tsunami waves begin with the water flowing away from shore?
This isn't seen in small-scale wave tank experiments and is therefore hard to believe. Is there even a simulation on the web showing significant recession from a positive pressure source like you describe? I like the simpler answer from Carlos more (it is surprising that most earthquakes would lower the ocean floor, but I guess it would make sense that the earth tends to stabilize into a more compact form).
Sep
7
comment Conservation Laws in Photon Parametric Down-Conversion
No matter what kp, ks, and ki you choose (by "example", I wanted some actual numbers), I don't think that you can conserve both energy and momentum. Instead, I think Ron Maimon is correct in his comment above. So, I'd say Wikipedia is wrong (in answer to my original question) and "parametric" is not used/defined well here.
Jul
20
awarded  Yearling
Jun
11
comment Atmospheric Circulation
If I'm skimming that paper correctly, their constructal model doesn't predict a single cell for >144h rotation periods (they just give references to other papers showing it), right?
Feb
25
comment Induction cooker + superconductive pot
At first, it will start to levitate. But, it will soon tilt due to a misbalance and then accelerate this tilt...the 3D shape of the superconductor will then determine how the induced currents flow. Of the three options you gave, I'd say "tremble".
Feb
23
answered Induction cooker + superconductive pot
Jan
9
comment Atmospheric Circulation
Thanks, good link. I get it now, but now would think that even a non-rotating earth could have multiple convection cells. So, I feel like simulation is always needed and there's no hope for the "justifiable formula" I asked for. For the simulator, it seems I need to add another parameter for the air's thermal radiation back into space.
Jan
7
comment Atmospheric Circulation
It's hard for me to understand how the vertical gradient could amplify circulation, so perhaps someone could simply show an airflow simulation for a non-rotating planet with one circulation cell? It seems to me that cooling of the upper atmosphere around the equator would actually slow circulation...but it's all quite complicated, especially modeling the thermal diffusion/convection within the air. Since there's not much interest in this question, I wonder if someone could just give a quantifiable explanation of the Ferrel cell; why would hot "south air" flow under cold "north air"?
Jan
2
asked Atmospheric Circulation
Sep
13
comment Dimension analysis of de Broglie equations
by the way, your p has incorrect units (you should only have first power for m and s)
Sep
13
answered Dimension analysis of de Broglie equations
Sep
8
accepted Simple PDE as a theory of everything?
Sep
8
awarded  Supporter
Sep
7
comment Conservation Laws in Photon Parametric Down-Conversion
Sorry, I think you have taken my question differently than intended. The 3 momenta are not inputs. I only get to input one momentum. The other 2 momenta are outputs.
Sep
7
comment Conservation Laws in Photon Parametric Down-Conversion
Or, maybe crystal momentum is what is being drawn and dispersion is the reason (the two emitted photons are moving slower than the original photon, so their energies are less than I had thought)?
Sep
7
comment Conservation Laws in Photon Parametric Down-Conversion
Wikipedia says they're usually off-parallel for this interesting case: en.wikipedia.org/wiki/Spontaneous_parametric_down_conversion Whether we talk about conservation of crystal momentum (for a bulk infinite crystal) or mechanical momentum (for finite crystal comparing global state before and after crystal passage), I don't get how that first Wikipedia figure can be true.
Sep
6
asked Conservation Laws in Photon Parametric Down-Conversion
Sep
4
answered If the universe started again with exactly the same conditions… would it be the same?
Aug
31
answered can hydrogen stay frozen in vacuum?