"John C. Polasek" <jpolasek@cfl.rr.com> wrote in message
news:q890m31sb7rfqg33o1bj1n54u203m60lvf@4ax.com...
: On Wed, 12 Dec 2007 17:28:33 GMT, "Androcles"
: <Engineer@hogwarts.physics_a> wrote:
:
: >
: >"John C. Polasek" <jpolasek@cfl.rr.com> wrote in message
: >news:dd10m3lej1j7n768ivrej97qr4niucg5eg@4ax.com...
: >: There is plenty of room for skepticism regarding science as purveyed
: >: by TV. Here, unless I have slipped up, is a glaring example.
: >:
: >: Last night on the History channel, program title "The Universe", the
: >: lady explainer was telling about tides. She said the moon produces
: >: much more gravity here than the Sun "cuz it so much closer".
: >:
: >: My figures show the Sun's gravity is 180 x as strong as the moons: we
: >: feel 3.3e-5 (moon) vs 5.9e-3 (sun) m/ss. Msun is 27 million x Mmoon.
: >
: >
: >Your figures are wrong, you left out the spherical inverse square law.
: >The moon is a less than a 1/5 million miles away, the Sun is 93,000,000
: >miles away. That makes a slight difference.
: >
: >:
: >: Then she says because the earth is rotating so much faster than the
: >: moon, its tides drag the moon to greater velocity.
: >
: >
: >: "As a consequence of this higher velocity, the moon's orbital radius
: >: is increasing".
: >: Doesnt seem so to me.
: >: V^2/R = MG/R^2
: >: or V^2*R = constant
: >: so larger velocity requires a smaller, not larger, radius.
: >: Did I slip up somewhere? Back me up on this. Be outraged.
: >: John Polasek
: >
: >I'm backing you down, not up. I'm outraged at your lack of knowledge.
: >The giant errors are yours.
: >Yes, a smaller radius does require a greater velocity, but when
: >a space craft accelerates (in the same direction) it attains a higher
: >altitude and a lesser velocity.
: But her story was that greater velocity gave greater altitude, which
: you at first also objected to.
: Then you make the muddy remark, restated, to the effect that
: "when a spacecraft *acclerates* it attains * lesser velocity* (lesser
: velocity/accelerate?) and higher altitude." Sounds like faulty energy
: management.
: I'll put it a different way. If the altitude R increases by 10% the
: velocity V has to decrease by 5%, contradicting her statement.
: What is your gripe with that? Point out the giant error, using the
: algebra of V and R instead of persiflage.



If it helps you at all, each orbit is elliptical (including Luna's) and
has a greater tangential velocity at periapsis (lowest point in the
orbit) than at apapsis (highest point the the orbit).
A boost at periapsis will increase the eccentricity of the ellipse,
a boost at apapsis will decrease it, so to obtain a circular orbit
with constant tangential velocity you need to increase the velocity
(accelerate) at the slowest part of the orbit when the satellite is
furthest away (apapsis). This has the effect of increasing the
altitude of periapsis and REDUCING the tangential velocity
THERE, the satellite doesn't "fall" as far, hence doesn't accelerate
Earthwards to the lowest point in the orbit where its tangential
velocity will be greatest.
Sorry if that is mud to you, but your assumption of a circular
orbit and a simplistic equation to model it based on that assumption
is mud to me and poor energy management on your part. Look
into Kepler's laws.

There is plenty of room for skepticism regarding science as purveyed
by this newsgroup. Here, because you have slipped up but arrogantly
pretend you know what you are blabbering about, is a glaring example.

I didn't see the show, therefore anything "she" may or may not have
said is hearsay to me upon which I will not comment unfairly. You
slipped up. See posts by others concerning conservation of angular
momentum. Ignore Uncle Stooopid's "quadrupolar dependence" crap,
he's trying to appear a smart arse (as usual) and confuses "dependence"
with "dependent". You may refer to the citation the jerk gave in which
no reference is made to Luna (for all the good it will do).