"spurious" wrote in message
...


Hi people, 1st post here, but have been lurking on and off for about a year.
I'm not sure if this is the right NG to post my question, but it does
seem weather related. well sort of, and it's one of those things I lie awake
at night thinking about:-)

The way I understand it, is tides are caused by the gravitation pull
from the moon and the sun. Looking at high/low tides of the Atlantic, it
seems the north east coast of the US has low tides as the same time as the
low tides on the west coast of UK. The water must be displaced somewhere and
I presume it is pulled up into a 'hump' by the moon passing over the
Atlantic.
I am no mathematician, but for tides to go in and out, the moon must
be displacing million and millions of tonnes of water.
Why then does the gravitation pull on the moon have no effect when it
passes over land?
Not a leaf on a tree or a flower will sway towards the moon.


Well they probably *do* but you would never notice it what with the
effect of wind and all that. Do you feel lighter at certain times of the
day due to the moon's gravitational pull on you? Probably not
With the oceans it's a different thing of course. Water is mobile
and can be pushed around by gravitational forces far more easily than
solids can. And don't forget that proper tides only occur on oceans
that are several thousands of miles wide. That's one *big* body of water!
And even then you only get at most a few 10's of feet difference between
high tide and low tide. That's insignificant compared to the size of the
body of water we are dealing with.

Col
--
Bolton, Lancashire.
160m asl.
http://www.reddwarfer.btinternet.co.uk
http://www.reddwarfer.btinternet.co....rPictures.html