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bio website markbeadles.com
location Columbus, OH
age 47
visits member for 2 years, 11 months
seen Jan 28 '13 at 17:55

Jan
27
revised What is the inertial frame that explains the Foucault Pendulum?
added 280 characters in body
Jan
27
comment What is the inertial frame that explains the Foucault Pendulum?
I'm making a statement. :) Sorry, not trying to talk at cross purposes. As the wikipedia article also states, the Foucault pendulum is not in an inertial frame. It is rotating, by an angle of −2π sin(φ) per day where φ is the latitude. At the poles the pendulum indeed does not rotate.
Jan
27
comment What is the inertial frame that explains the Foucault Pendulum?
@JohnRennie the triangle you describe rotates with the Earth. Consider the point on that plane, which is on the ceiling where the pendulum is attached. This point is in a building attached to the surface of the earth and therefore rotates with a period of 24 hours. Therefore that plane is itself rotating around the center of the earth as well.
Jan
27
comment What is the inertial frame that explains the Foucault Pendulum?
The sidereal day is 23.93447 hours.
Jan
26
comment What is the inertial frame that explains the Foucault Pendulum?
@JohnRennie What you say is true only at the poles. Elsewhere the pendulum must rotate.
Jan
26
revised What is the inertial frame that explains the Foucault Pendulum?
added 346 characters in body
Jan
26
comment What is the inertial frame that explains the Foucault Pendulum?
@Vam'çá it's not gravity that is causing the apparent rotation. I say "apparent" rotation because that's what it is. We are seeing the effect of a combination of real and fictitious forces that, when observed from our viewpoint as stationary with respect to the accelerating Earth, looks like rotation.
Jan
26
answered What is the inertial frame that explains the Foucault Pendulum?
Jan
26
comment why is there no ninth gluon?
@mbq thanks for checking it for me!
Jan
26
awarded  Enthusiast
Jan
26
awarded  Citizen Patrol
Jan
26
comment why is there no ninth gluon?
See also this question and its answer on "colorless" gluons.
Jan
25
comment why is there no ninth gluon?
Interesting - it postulates that the color symmetry is broken $U(3)$ instead of $SU(3)$ and that the broken symmetry gives an extremely massive singlet gluon.
Jan
25
answered why is there no ninth gluon?
Jan
23
comment Earth's stationary iron core
@RonMaimon Of course you are right and I spoke loosely. Sorry.
Jan
23
comment Earth's stationary iron core
In physics when we say "stationary" we must always ask "stationary relative to what?"
Jan
23
comment Earth's stationary iron core
Great links, Adam - in particular I'm fascinated by the discovery that the core is asymmetrical.
Jan
22
comment What is the meaning of speed of light $c$ in $E=mc^2$?
Possible duplicate of this question; you may want to take a look at that.
Jan
19
awarded  Quorum
Jan
19
comment Does a perfect mirror behave the same as a blackbody radiator?
This paper addresses your question, I believe, but I do not have access to full text from here. "Radiation from perfect mirrors starting from rest and the black body spectrum"