Does Python cause tides?

[Peter Hansen]

Steven D'Aprano wrote:
> Roy Smith wrote:
>> Steven D'Aprano <steve at REMOVEMEcyber.com.au> wrote:
>> >High and low tides aren't caused by the moon.
>> They're not???
> 
> Nope. They are mostly caused by the continents. ...
> The true situation is that tides are caused by the interaction of the 
> gravitational fields of the sun, the moon and the Earth, the rotation of 
> the Earth, the physical properties of water, its salinity, the depth, 
> shape and composition of the coast and shoreline, the prevailing ocean 
> currents, vibrationary modes of the ocean (including up to 300 minor 
> harmonics), ocean storms, and even the wind. You can understand why we 
> usually simplify it to "the moon causes the tides", even though the moon 
> isn't even the largest contributing factor.
> 
> See, for example:
> 
> http://home.hiwaay.net/~krcool/Astro/moon/moontides/

Steve, please go and read that page again.  While I readily accept that 
you may be far more of an expert on tides than I, Roy, and whoever 
contributed to the Wikipedia article, nearly every section on the page 
that *you* referenced directly contradicts your basic claims.  I quote:

"Tides are created because the Earth and the moon are attracted to each 
other..."

"The sun's gravitational force on the earth is only 46 percent that of 
the moon. Making the moon the single most important factor for the 
creation of tides."  [you said the moon isn't the largest factor]

"Since the moon moves around the Earth, it is not always in the same 
place at the same time each day. So, each day, the times for high and 
low tides change by 50 minutes."  [if the moon were not such a large 
cause, it wouldn't have this effect]

I believe you are still just saying that the *magnitude* of the tides is 
greatly affected by other things, such as the shoreline, but what I keep 
reading is you basically saying "the moon is not the cause and is only a 
minor factor".

I also see nothing to suggest that if the moon and the sun were removed 
from the picture, there would be much in the way of tides at all.  (The 
page you quoted says the sun has about 46% the effect of the moon which, 
if true, means the statement "the presence of the moon and the sun cause 
tides" still seems pretty accurate, certainly not a "lie for children" 
but merely a simplification, if anything.

-Peter