mattbatson said:
I have done some reading, and found articles with little to no references (to scientific journals) that proclaim that although humans are mostly water...the moons gravitational pull has very little, if any, effect on our bodies.
It's not hard to do a few, rough calculations to prove this to yourself. For starters we can make a few approximations, while keeping in the spirit of the topic:
(a) Let's assume the moon is spherical.
(b) Let's assume that the moon is a constant 385 x 10
6 meters away. The moon's actual distance varies slightly (from around 360 x 10
6 to 410 x 10
6 m) due to the fact that it has an elliptical orbit and the fact we are on the Earth, and the Earth has its own radius and is rotating. But 385 x 10
6 meters is a rough approximation.
The gravitational acceleration caused by our moon can be determined by
a = G \frac{m}{r^2}
where
G is Newton's gravitational constant,
G = 6.67 x 10
-11 [m
3 kg
-1 s
-2]. The mass of the moon ,
m, is 735 x 10
22 kg. Plugging the numbers in gives us
a = (6.67 \times 10^{-11}) \frac{7.35 \times 10^{22}}{(384 \times 10^6)^2} \mathrm{[m \ s^{-2}]}
= 0.0000332 \ \mathrm{m/s^{2}}
The direction of that acceleration depends on where the moon is, of course. If you see the moon near the horizon, the accleration is coming from that direction. If you see the moon nearly straight up, the acceleration is directed in that direction. If it's a new moon at midnight, the direction is down.
Compare that to the acceleration caused by the Earth's gravitational attraction on our bodies (we being on the surface of the Earth), which is approximately 9.8 \ \mathrm{m/s^{2}}, straight down. As you can see, the moon's gravitational pull is barely a drop in the bucket, compared to the Earth's.
You might have been curious about the tides. Yes, the gravitational pull from the Moon (and the Sun too) cause tides. And these tides cause the surface level of the water to raise and lower by somewhere on the order of 1 meter (roughly a meter -- of course that depends on some other geographical factors, but let's just say roughly around a meter or so, give or take.) Now consider that the average ocean depth is in the thousands of meters; ~3000-4000 meters is typical. The deepest part of an ocean is over 10,000 meters. So a tidal variation of about a meter isn't all that much. (I don't want to get into the math/physics of the tides though. It's significantly more complicated than the math used above, although it can be done.)
I don't believe that there is more crime during full moon's, for instance...however, there are a couple of studies out there which seem to say that there is a coorelation.
I'm looking for actual scientific evidence that our bodies are not physically affected.
Does anyone know where I should start looking?
thx
I don't know of such sources, but I haven't looked either . If you did start looking yourself, you should make an effort to remove biases such as brightness (i.e. reflection of the Sun's light off the Moon, directed back to Earth). When the moon is full, it's brighter out. It's pretty obvious. That alone might very well have an effect on people's habits and nighttime shenanigans. It seems to me as though you are interested in the variational effects of the moon's gravitational pull, which is far less noticeable to people than the moon's brightness.
Just a little.
