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Mild mannered
2004-Dec-21, 10:13 AM
Do we way less in the daytime than at night due to the position of the sun and the effect of its Gravity?

How much by?

antoniseb
2004-Dec-21, 02:17 PM
Originally posted by Mild mannered@Dec 21 2004, 10:13 AM
Do we way less in the daytime than at night due to the position of the sun and the effect of its Gravity?

How much by?
We weigh [on average] least at noon and midnight, and most at dawn and sunset. This effect varies by latitude. As you can tell by looking at your scale repeatedly the effect is pretty small. It should also be noted that the similar effect we get from the relative position of the moon is about three times greater than the one for the Sun. This is the same effect that causes the tides.

astromark
2004-Dec-22, 03:00 AM
Your waight diferance is tidal... but your diet is not. Waigh your self on the same set of scales at the same time. go on a diet. Astronomy does not hold the answer here.
I'm sorry, I am only kidding....
I did not think the tidal forces on us would be measurable. I might be wrong.. You all have a good feed for xmas and forget your waight for a week or so a...

Mild mannered
2004-Dec-22, 09:42 AM
Thanks guys - sorry if this question was very newbie

Ant - I forgot about the moon!

Astromark - You stole my punch line! :D LOL

Diet in the New Year - honest - same as last year!!!

A good feed for all and to all a good feed!! :D :D

Crux Australis
2004-Dec-24, 12:36 AM
Guys.. you have keft out one very important thing re weight: its the body fluids you retain over Xmas and on New Year's eve. ....

The more u drink.. the more u weigh and the vice versa.. and all the fliud going the drain hole! no wonder u loose weight! [FONT=Impact] also the parts of earth u live at too has a bearing on ur weight. :rolleyes: :rolleyes: ;) have a great time guys..hic,,

Mild mannered
2004-Dec-24, 10:27 AM
Abso(hic)lutely! :D

marrsc
2005-Jan-21, 05:09 AM
I just found this forum and I am fascinated. The first reply is incorrect You would weigh the least at noon and the most at midnight. You would weigh the absolute most, at midnight during a lunar eclipse that was happening on the other side of the earth. You would weigh the least during a solar eclipse at noon.

antoniseb
2005-Jan-21, 06:36 AM
Originally posted by marrsc@Jan 21 2005, 05:09 AM
The first reply is incorrect You would weigh the least at noon and the most at midnight.
I'm wrong? Why are tides highest twice a day if you only weigh least once a day? You are correct that the greatest effect is during solar or lunar eclipses [or any full or new moon] at noon or midnight, but in both cases, the effect is least weight. It is also the case that lunar perigee is important to this as well.

marrsc
2005-Jan-21, 05:15 PM
"Without getting too much into the technical details, there are two bulges because of the differential gravitational forces. The liquid at point A is closer to the Moon and experiences a larger gravitational force than the Earth at point B or the ocean at point C. Because it experiences a larger attraction, it is pulled away from the Earth, toward the Moon, thus producing the bulge on the right side. Loosely, we may think of the bulge on the left side as arising because the Earth is pulled away from the water on that side because the gravitational force exerted by the Moon at point B is larger than that exerted at point C. Then, as our idealized Earth rotates under these bulges, a given point on the surface will experience two high and two low tides for each rotation of the planet."
http://csep10.phys.utk.edu/astr161/lect/ti...time/tides.html (http://csep10.phys.utk.edu/astr161/lect/time/tides.html)
I shamelessy plagarised the paragraph above. This is the kind of fascinating interaction I love. This has caused me to learn a greater understanding of tides. I had not considered that the earth was being pulled out from under the ocean on the back side of the model. This is what causes the tidal bulge on the back side.