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location Netherlands
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Apr
16
awarded  Nice Answer
Apr
14
comment Static electricity and door handles
There are thousands of tricks - keys, elbows, anything that avoids an arc from your fingers to the door handle.
Apr
14
comment Does universe calculate?
Also, what does 1/3 have to do with approximations? It's exact, and it can be used in an exact way. One third of 71 exactly 23 2/3.
Apr
14
answered Can we theoretically balance a perfectly symmetrical pencil on its one-atom tip?
Apr
10
comment In a noiseless environment, how accurate do today's transmitters send EM waves?
You're wondering about state of the art, which is essentially engineering. Scientifically you're looking at the Heisenberg uncertainty principle, ΔEΔt > ħ. E would the photon's energy, which of course is ħω so ΔωΔt > 1.
Apr
10
answered Phase change on reflection only 0 and $\pi$ allowed
Apr
8
answered Why are solar panels blue, rather than black, when black absorbs more light?
Apr
8
comment Carbon 14 disintegration
Even if the original carbon atom was rather positive (e.g. CCl4, chloroform) the excess energy is still enough to escape not just the atom but the whole molecule.
Apr
8
awarded  Organizer
Apr
8
comment Variation in spring constant with respect to the length and no. of coils
Instead of cutting the spring in half, imagine what happens if you paint a red dot on the middle. That thought experiment should tell you what happens to the halves above and below the dot.
Apr
8
revised Variation in spring constant with respect to the length and no. of coils
edited tags
Apr
8
answered Stacking batteries and electron flow
Apr
8
comment Drying clothes with the sun's heat, without any air
@LorenPechtel: That just means you need a work cycle. Pull the dryer vacuum - water evaporates below 300K. In the condensor, you let the air recompress to 1 atm. The water now condenses out of the air, and exits the dryer still cold. Reheat the dried-out air, and let it back in. This cycle certainly works, it's a common design for desalination plants.
Apr
2
comment Is speed of propeller-driven airplane limited by the speed of sound?
TBH I don't think we need to account for propeller tips reaching hypersonic speeds.
Apr
2
comment Is speed of propeller-driven airplane limited by the speed of sound?
There's no such thing as suction pressure. A vacuum doesn't suck at all. It's the positive air pressure on the other side which pushes. And that pressure isn't really limited.
Apr
1
comment Does a photon travel in all directions?
Light does behave like a wave, but a "beam" is actually a wave with a main lobe and a small, narrow set of sidelobes. The "laser beam viewed from the side" cannot be explained by this, and furthermore the effect goes away in vacuum. Borilla's answer is right.
Apr
1
awarded  Pundit
Mar
31
comment Why doesn't light affect a compass?
@robertbristow-johnson: Sure about that? 6 centimeter / 600 nm is 6E-2 / 6E-7 = 1E+5. We in fact may be down to kilotwitches.
Mar
31
comment Is it possible that every single isotope is radioactive, and isotopes which we call stable are actually unstable but have an extremely long half-life?
Note that a lack of certainty in details doesn't necessarily matter at a higher level. Say we have two isotopes A and B which might decay as A->B+stuff or B->A+stuff. Now it's possible that neither decay is possible, or that one of the two is possible, but in any of the 3 scenario's there is a stable isotope. When we see an actual decay, we know which of the two would be stable. (This is what math knows as non-constructive proofs: we can prove that some X exists even if we don't know all properties of X)
Mar
31
comment Is it possible that every single isotope is radioactive, and isotopes which we call stable are actually unstable but have an extremely long half-life?
The p->n decay indeed is the only one that really matters, because the result is not an isotope. All other decays are from one isotope to another with lower energy. That means there's a partial order with at least one minimum. Makes sense: you can't have a cycle of unstable isotopes A->B->C->A, that would be a perpetuum mobile.