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visits member for 4 years, 1 month
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Mar
25
answered Why is the prospective new kilogram standard a sphere?
Feb
26
comment Intuition as to why the orientation (of a 3D object) is not a conserved quantity?
@A.Donda there would still be a large class of objects whose "centre of angle" vector was the (directionless) zero vector despite having a recognizable orientation (ie. no circular symmetry).
Jan
19
comment Relationship Between Acoustics and Gravity?
@soultrane, you mean earthquakes? It's still much easier to detect the vibrations themselves than any gravitational waves given off, and in fact earth tremors are considered unwanted "noise" to the people trying to detect astronomical gravitational waves (LIGO and others), because they vibrate the detector directly with no need for gravitational transmission.
Jan
19
answered Relationship Between Acoustics and Gravity?
Jan
15
awarded  Curious
Jan
14
asked fate of a hadron in a big rip
Jan
4
comment If gravitation is due to space-time curvature, how can a body free-fall in a straight line?
So has anyone managed to measure the purely spatial component of curvature due to gravity? (eg. angles of a triangle not summing to 180°) I suppose you'd want as large a triangle as possible, and you'd use laser beams as your "straight ruler", but they get deflected by gravity too, which you would have to take into account. And on Earth, refracted by variations in air density. Maybe it would be easier in space, even if the curvature is less.
Dec
24
comment If gravitation is due to space-time curvature, how can a body free-fall in a straight line?
OK. And this seeming asymmetry in curvature between space and time is just due to the conversion factor being a very large $3\times 10^8$ m/s? Or also the different nature of time?
Dec
24
comment If gravitation is due to space-time curvature, how can a body free-fall in a straight line?
These two statements seem to contradict: "a straight line - it just looks like a parabola to us", and, "the geometry around the Earth's surface is approximately Euclidean".
Dec
24
answered Is there a strong force analog to magnetic fields?
Dec
24
asked Gravitational… confinement?
Dec
20
comment Are fundamental forces always attractive/repulsive, i.e. parallel to the separation?
@CuriousOne, I'm not asking whether such a thing has been observed (although I'd be interested if it had!), I'm asking whether there are theoretical reasons to believe that such a thing is not possible.
Dec
20
awarded  Editor
Dec
20
revised Are fundamental forces always attractive/repulsive, i.e. parallel to the separation?
added 273 characters in body
Dec
20
comment Are fundamental forces always attractive/repulsive, i.e. parallel to the separation?
@CuriousOne yes that is an interesting article, +1. My question is about whether such things can't exist in the real world.
Dec
20
comment Are fundamental forces always attractive/repulsive, i.e. parallel to the separation?
@jabirali yes, assume the particles are travelling slowly relative to the speed of light and don't take into account the small difference between where they "currently" are (if that means anything) and where they've been.
Dec
20
comment Are fundamental forces always attractive/repulsive, i.e. parallel to the separation?
@jabirali not at all. Do you imagine it doesn't apply to the hypothetical monopole case?
Dec
20
comment Are fundamental forces always attractive/repulsive, i.e. parallel to the separation?
@CuriousOne, you can always obtain classical behaviour in the limit. Consider the question to be about "an electrically charged large object" passing by "a magnetically charged large object".
Dec
20
asked Are fundamental forces always attractive/repulsive, i.e. parallel to the separation?
Sep
23
awarded  Commentator