Answer 1:
To discuss tides, first we have to discuss what
forces are acting on the oceans. If the moon was
the only force pulling the oceans then we would
expect high tides at exactly 12 midnight and 12
noon everyday (which is not the case). The gravity
of the moon and sun draw the ocean towards their
centers. The moon causes a bigger affect on ocean
tides than the sun because although the sun is
larger it's also much much further away. All of
this means that high and low tides are determined
mainly by a tug-of-war between the pull of
gravities of the earth, the moon and the sun.The
size of high and low tides are determined by how
the pull of the moon and sun line up-- If the moon
and sun are on the same side of the earth, they
are both pulling the ocean in the same direction
so you get a bigger tide (called a spring tide).
If they are pulling in opposite directions then
you get what's called a neap tide. So not all high
tides are equal, and not all low tides are equal,
depending on the position of the moon relative to
the sun.
Spring
Tides, click here
You are correct by saying that when you see the
moon, it is pulling the ocean in front of you
outwards from the earth, but how low or high of a
tide also depends on where the sun is. Also, the
moon takes longer to rotate around the earth than
24 hours, in fact it takes 24 hours and 50
minutes, so the tide cycle (high vs. low) changes
every day.
Here is a great animation that shows how the tides
change within a day, but that the cycle takes more
than 24 hours.
Click
here to watch
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