Density is the same regardless of the effects of gravity

Rob L
"OzWineKitz" > wrote in message
om...
> This is along the same lines as my previous post.
>
> Its a fact that the orbit of the moon varies up to say 5000km during a
> normal monthy (28day) orbit of the moon - right? The perigee and
> apogee, (vertical position in reference to the equator), also vary
> during a 27 day cycle.
> http://www.fourmilab.ch/earthview/pacalc.html
>
> Its also a fact that the Sun also has a gravitational influence on our
> liquids but it is 2 1/2 times less than the Moon.
>
> So if the moon can afect tides, by pulling water away from the earth
> due to gravitational influence, can it also affect our Hydrometer
> readings? Bear in mind that if the moon is pulling at our precious
> brew at the same force as the ocean, then our brew should be less
> dense right? If its less dense then our hydrometer will sink more,
> won't it? If so then we could be getting a false SG reading because
> the brew will appear a lower SG than it really is.
>
> Lets say it's a Full Moon at its perigee in Cairns - Australia on Dec
> 22nd 2003, (its also a high tide), and we take a Hydrometer reading at
> Sea Level with Pressure 1010mb - and it reads SG 0.992, then what will
> the SG read when the moon is at is apogee on Jan 3rd 2004, at sea
> level, with the same atmospheric pressure? Might it read higher?
>
> I can hear many say - WHO CARES? But the reality is this, with many
> wines I have measured the same SG but with noticably slight variations
> in sweetness when tasting - even though I am using the same juice and
> methodology for winemaking and the same hydrometer. Some might put it
> down to variations in the actual juice and differences in yeast colony
> count, etc...
>
> But could the relative local atmospheric pressure and Moon position
> influence the accuracy of my SG readings?
>
> Cheers,
> Steve!