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visits member for 3 years, 8 months
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Dec
16
comment How far can light go?
@Aziraphale the individual photons lose energy (see a lot of related questions/answers on this site on how this ties together with energy conservation etc)
Dec
14
accepted What low-level process drives a frequency-doubling crystal?
Dec
9
answered Why is light different than sound in terms of the assumptions we make regarding causality?
Nov
27
comment Antenna to characterise lightning
thanks! don't forget to mark the answer as answered, if you think its an answer that is :)
Nov
27
answered Antenna to characterise lightning
Nov
25
awarded  Good Answer
Nov
24
awarded  Nice Answer
Nov
24
answered Can a car steer on a frictionless surface?
Nov
24
comment Neutrino Oscillation and their gravitational implications
Read this just now and wondered if it would be proper to add that it can be confusing to mix the propagation of a quantum superposition of mass states with classical effects of gravity (as the question implies). There isn't a single well-defined gravitational field along the "classical" neutrino trajectory because of this (and it would require a good theory of quantum gravity to describe it eventually). But I might mix something up, I'm not a particle physicist :)
Nov
24
comment “Reality” of length contraction in SR
Another way of seeing the development of relativity etc., is that the parameters used to describe "reality" before were simply not fundamental (in as good sense of the word as can be used). If physicists had originally stumbled upon lorentz-invariant properties from the beginning and used them, there would have been less of a need for a theory of SR (or any need). It makes you wonder how many other parts of physics are historically anchored. Many, I bet..
Nov
20
answered How do radio waves reach receivers without being canceled out by interference?
Nov
15
answered What happens to the energy of photons when two light waves with plane wavefront interferes destructively?
Oct
26
revised A problem regarding the Elitzur-Vaidman bomb tester
clarify when the interaction-free measurement actually gives extra info
Oct
26
answered A problem regarding the Elitzur-Vaidman bomb tester
Oct
25
comment Why do weak interactions give such slow decay rates, if the analog of the fine structure constant isn't signifigantly small?
The coupling constant is smaller by a large magnitude, for "normal" energies. The force carrier W- is also massive compared to the photon, and results in a short range behaviour as well. For much higher energies though, the EM and weak forces are unified and there the coupling "constants" do even out as you suggest.
Sep
21
comment Can light waves cause beats?
I like these kind of setups, seems they give a lot of nice intro value (compared to the gear/setup effort involved) to engage students or researchers in the quantum fundamentals/optics areas.
Sep
20
comment Entanglement g-2-experiment - Which components do I need?
It is true that it's difficult to find descriptions regarding basic experimental setup and tuning in quantum optics papers in general. Papers that describe their setups for doing more advanced experiments never go through the detailed steps required for alignment or where/how to purchase the right stuff. It is of course implicitly assumed that whoever is reading those things work in the field and know the basics :) I do think it might be easiest to discuss in person with someone at a local physics lab.
Aug
23
awarded  Civic Duty
Jul
15
comment How can molecule of a few angstroms absorb visible light of a few hundred nanometers?
About shortening classical antennas - typically, ceramic "chip" antennas can be used to reduce the quarter-wave antenna size due to their much higher dielectric constant. You can pack a copper antenna into a size one tenth of the quarter-wave (in vacuum). There are obviously other drawbacks with these though.
Jul
12
answered Collision Resolution System Adding Velocity Into System