> > > On 01/11/2011 04:43 PM, David Jonsson wrote: >> Yes, under "effects of centripetal acceleration" which is by the way >> an erroneous title since it should be centrifugal acceleration. > > Don't think so. In Newtonian terms, the acceleration's centripetal, > caused by the centripetal force, which is provided by gravity. The > "fictitious" centrifugal force is the outward-pointing acceleration of a > uniformly moving non-rotating object (times its mass) which is observed > from a rotating frame. However, in the rotating frame, the acceleration > you're concerned with -- and the acceleration which leads to the > "centrifugal force" -- is directed inward, and is "centripetal".
If I didn't understand incorrectly, what David is saying is that when you determine G empirically, by example by using a scale, centrifugal acceleration must be discounted, because it's affecting the scale weights. That is, the scale weights are subjected not only to gravitation, but also to a centrifugal force, because they are inertial masses in rotation. And also translation, by the way. To be extremely precise, you would also need to consider the component of Earth's acceleration around the Sun, and other accelerations. I suppose all those influences must be much smaller than variations in G due to ambiental and geographical factors. The same for the difference between sidereal and solar day, probably. > > >> >> What I write there is in its entirety: >> The denominator should use the sidereal day of 86 164.0905 seconds >> instead of 86 400 since inertia is relative the stars and not the Sun. >> David Jonsson 20:44, 11 January 2011 (UTC) --- Preceding unsigned >> <http://en.wikipedia.org/wiki/Wikipedia:Signatures> comment added >> by Davidjonsson <http://en.wikipedia.org/wiki/User:Davidjonsson> (talk >> <http://en.wikipedia.org/wiki/User_talk:Davidjonsson> . contribs >> <http://en.wikipedia.org/wiki/Special:Contributions/Davidjonsson>) > > That sure sounds right. (Just to be nit picky, I might argue that > rotation is absolute, and the stars just provide some convenient distant > markers; there's no reason I can see to think a centrifuge wouldn't work > even if the universe were nearly empty.) > > >> >> David >> >> David Jonsson, Sweden, phone callto:+46703000370 >> >> >> >> On Tue, Jan 11, 2011 at 10:39 PM, Harry Veeder <hlvee...@yahoo.com >> <mailto:hlvee...@yahoo.com>> wrote: >> >> Is this the right link? >> Harry >> >> >> *From:* David Jonsson <davidjonssonswe...@gmail.com >> <mailto:davidjonssonswe...@gmail.com>> >> *To:* vortex-l <vortex-l@eskimo.com >> <mailto:vortex-l@eskimo.com>> >> *Sent:* Tue, January 11, 2011 3:47:23 PM >> *Subject:* [Vo]:g on Wikipedia erroneously defined >> >> Hi >> >> Ain't I right? >> >> http://en.wikipedia.org/wiki/Talk:Standard_gravity#effect_of_centripetal_acceleration >> >> Sidereal period should be used and not solar. >> >> Do you support a change? >> >> David >> >> David Jonsson, Sweden, phone callto:+46703000370 >> >> >> >
