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Functional programming enthusiast, audio engineer & musician. Whilst not busy with any of that, I study physics at Universität zu Köln / Bonn-Cologne Graduate School.


Apr
11
awarded  Custodian
Apr
11
reviewed Approve suggested edit on Why can lights(photons) bends in a curve through space without mass?
Apr
9
comment Free energy device - QEG. Is this for real?
I'm afraid this kind of short "it's against the laws" argument is really counterproductive for fighting the "gratis energy" craze. The laws of thermodynamics are themselves only a theory. A theory that's extremely well-backed by experiment, that's the point. Talking about violated laws OTOH is bound to sound to the layman like scientists have just invented them for fun, or indeed to make money from electricity business.
Apr
7
comment Has the collapse of wave function due to observation been recorded?
Note that the graphic is misleading in its rather sharp lines on the screen. You might get such lines for an diffraction grating, but for a double slit it's always much more "smeared", as shown in Anna v's answer. In particular, taking a measurement about which slit a particle went through will generally not make it suddenly "fly in a straight classical trajectory". The outcome will rather be a single indistinct blob on the screen.
Apr
1
comment Why does grinding steel create sparks but aluminium doesn't?
I'd reckon the difference has to do with the properties of the oxide film. $\mathrm{Al}_2\mathrm{O}_3$ sure is physically very stable; I suppose that's why it protects so much better than iron oxide can.
Apr
1
comment Optimizing water boiling
Also, I think the premise is wrong. Actually the bottom of the pot will in either scenario reach close to $100^\circ\mathrm{C}$ much before the water is boiling: the heat transfer through the water is driven by liquid convection but also to a good part through vapour bubbles.
Apr
1
comment Optimizing water boiling
@Davidmh: that depends strongly on the particular design of the stove. For an induction stove there isn't even any temperature difference; only the change in resistivity plays a part. Even for heat-transfer based stoves, the temperature difference between heating element and pot will at all times be vastly larger than the difference between pot and environment, so that's still the more crucial parameter. — Anyway both effects just amplify each other: less power means longer time for energy to get lost through convection, the rate of which depends on temperature.
Apr
1
answered Optimizing water boiling
Mar
31
comment Can electrons coincidentally flow along a circuit to cause current?
If you're "talking even probabilities like $1 : 10^{-1000}$" then the answer to pretty much any question you can think of approaches "yes". Read any Douglas Adams? (Which is not saying that everything he writes makes any sense scientifically.) Though you'll generally need numbers more like $10^{10^{20}}$ for "interesting macroscopic weirdness".
Mar
31
awarded  Critic
Mar
31
answered Why does the topological entropy scale with $\log(L)$ in 1D?
Mar
31
comment Home experiment question
Ahm, this is wrong. The pressure from the top is not $0$, why would it be? Indeed for a short straw the pressure from top will be almost equal to the pressure from bottom, only slightly less to counter the weight of the water. (Of course, you can argue with relative pressures alone, simply gauging the pressure on top to $0$, but then please make that explicit.)
Mar
30
comment Why does the gas cloud of an underwater gunshot pulse?
Well, that wiki article is about "ordinary" gas bubbles, the ones that are permanently stable under their own inner pressure. Those behave in many ways quite different from cavitation vapour bubbles.
Mar
29
comment Why does the gas cloud of an underwater gunshot pulse?
Where do you you see a small amplitude here? I think this is in fact quite a good example of an oscillation that's totally unrelated to the usual 2nd-order differential equation. I know little about the processes involved in cavity collapse, but pretty sure it's very much more complicated. For one thing, a prediction of a $\ddot x \propto - x$ model would be that the frequency is constant, but pretty clearly big bubbles oscillate slower than small ones.
Mar
29
awarded  Nice Answer
Mar
29
comment What is the physical meaning of a “complete” Hilbert space in QM?
@V.Moretti: good point. Though I suspect the majority of physicists wouldn't care, and just pretend all operators are bounded...
Mar
29
revised What is the physical meaning of a “complete” Hilbert space in QM?
added 286 characters in body
Mar
29
comment Why does the gas cloud of an underwater gunshot pulse?
Not really: there's not that much heat in fact, only, a round obviously contains quite a lot of energy in its explosive! The interesting thing is that this heat gets concertrated in such a small space, that's what causes the temperature to rise so remarkably high.
Mar
29
answered Why does the gas cloud of an underwater gunshot pulse?
Mar
29
answered Is commutation relation an equivalence relation?