Weight Measurement on Mutually Orbiting Planets

Jonnyb42
Messages
185
Reaction score
0
So at the end of the lengthy thread https://www.physicsforums.com/showthread.php?t=404650", a similar but new question of mine arose:

If you consider the Earth rotating, you can measure differences in weight at different points on the Earth (namely, the extremes being the poles and the equator.) I am assuming you know why, etc.
Now if you have two mutually orbiting planets, I wanted to verify that if you measured weight at the point on a planet facing the other planet, and compared it with the weight measured at the opposite side of the planet, they should be approximately the same. (Assuming the diameters of the planets are negligible compared to their separation)
Or also, I am verifying that their revolution does not affect this measurement.

P.S.
I am asking this because when I originally posted the above thread, I had in mind that that measurement was not the same, as if it were similar to a merry-go-round, however I recently realized that this shouldn't be so, and before I went on to think about it more I wanted to verify that I'm right.
 
Last edited by a moderator:
Physics news on Phys.org
Tidal gravity is measurable. The difference is greatest not between the zenith and nadir points but between the point at which the other planet is at zenith (or nadir) and a point where the other planet is on the horizon. For example, the tidal gravitational effects due to the Sun and Moon on the surface of the Earth vary by up to 0.3 milligal over time (a gal is 1 cm/s2), a quantity that is easily measurable by precision gravimeters.
 
Thread 'Can this experiment break Lorentz symmetry?'
1. The Big Idea: According to Einstein’s relativity, all motion is relative. You can’t tell if you’re moving at a constant velocity without looking outside. But what if there is a universal “rest frame” (like the old idea of the “ether”)? This experiment tries to find out by looking for tiny, directional differences in how objects move inside a sealed box. 2. How It Works: The Two-Stage Process Imagine a perfectly isolated spacecraft (our lab) moving through space at some unknown speed V...
Insights auto threads is broken atm, so I'm manually creating these for new Insight articles. The Relativator was sold by (as printed) Atomic Laboratories, Inc. 3086 Claremont Ave, Berkeley 5, California , which seems to be a division of Cenco Instruments (Central Scientific Company)... Source: https://www.physicsforums.com/insights/relativator-circular-slide-rule-simulated-with-desmos/ by @robphy
In Philippe G. Ciarlet's book 'An introduction to differential geometry', He gives the integrability conditions of the differential equations like this: $$ \partial_{i} F_{lj}=L^p_{ij} F_{lp},\,\,\,F_{ij}(x_0)=F^0_{ij}. $$ The integrability conditions for the existence of a global solution ##F_{lj}## is: $$ R^i_{jkl}\equiv\partial_k L^i_{jl}-\partial_l L^i_{jk}+L^h_{jl} L^i_{hk}-L^h_{jk} L^i_{hl}=0 $$ Then from the equation: $$\nabla_b e_a= \Gamma^c_{ab} e_c$$ Using cartesian basis ## e_I...
Back
Top