by MarkBour » Sun Aug 05, 2018 10:47 pm
BDanielMayfield wrote: ↑Sun Aug 05, 2018 2:42 pm
neufer wrote: ↑Sun Aug 05, 2018 4:17 am
MarkBour wrote: ↑Sun Aug 05, 2018 12:12 amWill people on that side of Earth weigh less than usual that night? Maybe by a yocto kilo, or something?
Tidal forces (uncompensated by free fall) are dominated by:
- 1) a close Super Moon plus the Sun at perihelion
2) a close Venus conjunction
Everything else is under the radar.
Tidal forces scale as
the cube of the angular diameter times the density:
Tidal force of a close Super Moon: 132,595 = (34.1')3 x 3.344 g/cm3
Tidal force of Sun at perihelion: 49,232 = (32.7')3 x 1.408 g/cm3
----------------------------------------------------------------------------------------------------
Tidal force of Venus at closest conjunction: 7.223 = (1.1')3 x 5.427 g/cm3
----------------------------------------------------------------------------------------------------
Tidal force of Jupiter at closest opposition: 0.772 = (0.835')
3 x 1.326 g/cm
3
Tidal force of Mars at closest opposition: 0.287 = (0.418')
3 x 3.9335 g/cm
3
----------------------------------------------------------------------------------------------------
Tidal force of Mercury at closest conjunction: 0.054 = (0.217')
3 x 5.243 g/cm
3
Tidal force of Saturn at closest opposition: 0.026 = (0.335')
3 x 0.687 g/cm
3
Interesting Q & A y'all. But Mark, notice that Art didn't completely answer your question. He left out some units for you or someonelse to finish the calculation. I could, but it was
your question. Oh, and the people on the dayside of the Earth would also feel a little lighter, but they'd be in the dark as to why.
Art, interesting that sweet little ole Venus exerts more than
10 times the pull of mighty Jupiter! Girl power!
Bruce
So, the Moon can reduce my weight when it is overhead (if it's a Super Moon) by 1.3 x 10
-7 g and the Sun by 5.0 x 10
-8 g. Then when we get an eclipse, the effect can be as strong as 1.8 x 10
-7 g, summing those together. Then according to Art's calculations, even if everything else lined up perfectly and under unrealistically good conditions for all of them, they would not total more than 8.4 x 10
-12 g, I think. Anyway, so just an eclipse event affects my weight by about 0.2 micro grams, and the others are in the realm of a few pico grams. My guess of a yocto gram was too low.
And thanks for the reminder, Bruce, the folks on
both sides of the Earth would feel lighter.
[quote=BDanielMayfield post_id=284728 time=1533480141 user_id=139536]
[quote=neufer post_id=284711 time=1533442620 user_id=124483]
[quote=MarkBour post_id=284707 time=1533427947 user_id=141361]Will people on that side of Earth weigh less than usual that night? Maybe by a yocto kilo, or something?[/quote]
Tidal forces (uncompensated by free fall) are dominated by:
[list] [b]1) [color=#FF00FF]a close Super Moon plus the Sun at perihelion[/color]
2) a close Venus conjunction[/b][/list]
Everything else is under the radar.
Tidal forces scale as [b][color=#FF0000]the cube of the angular diameter[/color] times [color=#0000FF]the density[/color][/b]:
[b][color=#FF00FF]Tidal force of a close Super Moon: 132,595 = (34.1')[sup]3[/sup] x 3.344 g/cm[sup]3[/sup]
Tidal force of Sun at perihelion: 49,232 = (32.7')[sup]3[/sup] x 1.408 g/cm[sup]3[/sup][/color][/b]
----------------------------------------------------------------------------------------------------
[b]Tidal force of Venus at closest conjunction: 7.223 = (1.1')[sup]3[/sup] x 5.427 g/cm[sup]3[/sup][/b]
----------------------------------------------------------------------------------------------------
Tidal force of Jupiter at closest opposition: 0.772 = (0.835')[sup]3[/sup] x 1.326 g/cm[sup]3[/sup]
Tidal force of Mars at closest opposition: 0.287 = (0.418')[sup]3[/sup] x 3.9335 g/cm[sup]3[/sup]
----------------------------------------------------------------------------------------------------
Tidal force of Mercury at closest conjunction: 0.054 = (0.217')[sup]3[/sup] x 5.243 g/cm[sup]3[/sup]
Tidal force of Saturn at closest opposition: 0.026 = (0.335')[sup]3[/sup] x 0.687 g/cm[sup]3[/sup]
[/quote]
Interesting Q & A y'all. But Mark, notice that Art didn't completely answer your question. He left out some units for you or someonelse to finish the calculation. I could, but it was [b]your[/b] question. Oh, and the people on the dayside of the Earth would also feel a little lighter, but they'd be in the dark as to why. :lol2:
Art, interesting that sweet little ole Venus exerts more than [b]10 times[/b] the pull of mighty Jupiter! Girl power!
Bruce
[/quote]
So, the Moon can reduce my weight when it is overhead (if it's a Super Moon) by 1.3 x 10[sup]-7[/sup] g and the Sun by 5.0 x 10[sup]-8[/sup] g. Then when we get an eclipse, the effect can be as strong as 1.8 x 10[sup]-7[/sup] g, summing those together. Then according to Art's calculations, even if everything else lined up perfectly and under unrealistically good conditions for all of them, they would not total more than 8.4 x 10[sup]-12[/sup] g, I think. Anyway, so just an eclipse event affects my weight by about 0.2 micro grams, and the others are in the realm of a few pico grams. My guess of a yocto gram was too low.
And thanks for the reminder, Bruce, the folks on [i]both[/i] sides of the Earth would feel lighter.