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Oct
23
reviewed Approve Work done by friction opposing a force at an angle
Oct
23
comment Kim delayed choice experiment
@John Fistere: "So you record the coincidences as you describe in real time as D0 oscillates." -- To say that "D0 oscillates" is a gross mis-characterization. Instead, D0 records at each "x position"; long enough for differences in rates to show up with some significance. We could think of D0 as one large camera sensor. "If you had four separate coincidence detectors" -- That's what we/Kim et al. have: Coinc. counters "D0D1", "D0D2", "D0D3" and "D0D4"; and they record what's shown in Fig.s 3 and 4. Obviously: always only one of these finds a coicidence, given one single laser photon.
Oct
22
answered Kim delayed choice experiment
Oct
22
reviewed Edit How far will the bullet travel before falling back to earth?
Oct
22
revised How far will the bullet travel before falling back to earth?
Edited formatting
Oct
22
revised Electron flow and electric potential
copy-editing
Oct
22
comment Angular velocity relative to different frames
@Lone Wolf: "If the object had translational acceleration and a body axis was fixed at a single point within the object, it sounds like the co-moving inertial frame must also move with the same acceleration (origins coincide at all times)" -- Such a frame/system would be (permanently) co-moving, but necessarily not inertial. However, in a flat region, it is possible to identify a family of instantaneously co-moving inertial systems, where the members of any one such system determine zero speed of the single accelerating material point "within the object" at only just one event.
Oct
22
suggested approved edit on Electron flow and electric potential
Oct
20
awarded  Strunk & White
Oct
20
revised Did the mass of the electrons went infinite in the experiment done by William Bertozzi in the 1960s?
corrected spelling the first name of W. Bertozzi, cmp. http://scitation.aip.org/content/aapt/journal/ajp/32/7/10.1119/1.1970770 ; corrected corresponding dates; copy-editing
Oct
20
answered Does a clock oscillating in a friction-free hole through the center of a planet run slower than a stationary clock on the surface?
Oct
20
reviewed Edit Why are refrigerators 4 degrees and freezers -18 degrees?
Oct
20
revised Why are refrigerators 4 degrees and freezers -18 degrees?
They were iceboxes, not refrigerators, and I corrected a minor spelling
Oct
18
revised General Theory of Small Oscillations and existence of solutions
copy-editing (incl. spelling of the title)
Oct
18
suggested approved edit on General Theory of Small Oscillations and existence of solutions
Oct
18
comment Branching fraction for Kaon decay
DarthPlagueis: "the branching fraction equation [... where] $\Gamma = 1/\tau$." -- It bears being pointed out that the relation between the (full) decay width $\Gamma$ and the mean life duration $\tau$ is instead: $$\Gamma = \frac{\hbar}{\tau}.$$ "$\tau$ [...] the mean lifetime" -- Note that the PDG is presenting the relevant duration values as "mean life".
Oct
18
comment Can a pair of members of a “rotating system” be characterized by one value of displacement magnitude?
@Floris: "It would help to have a diagram" -- A diagram illustrating the described setup: two participants $A$ and $B$ moving on circular trajectories around one member ($C$) of an inertial system, with equal (non-zero) angular velocities? Well, I'll be happy to try as soon as I get the means to do so; i.e. as soon as our version of MathJax supports pstricks commands. "and a definition of "ping duration"" -- The duration of a specific participant from having indicated a signal until having recognized some other specific participant having recognized that signal indication.
Oct
18
comment Can a pair of members of a “rotating system” be characterized by one value of displacement magnitude?
@Floris: "Are you asking if the distance between A and B is independent of the frame of reference?" -- Well, using these terms, I'm asking whether A and B can be attributed a value of distance with respect to each other at all. Of course I'm asking about that in the proper sense: the pair (A B) itself to be characterized; I'm not asking about distance values which might be attributed to any other pairs of participants, or even about "appearances".
Oct
18
asked Can a pair of members of a “rotating system” be characterized by one value of displacement magnitude?
Oct
18
reviewed Approve Law of inertia, Frames of reference