Does Python cause tides?

[Terry Hancock]

On Wednesday 15 June 2005 05:13 am, Peter Hansen wrote:
> 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.

Okay, I haven't read the book, but I suspect that "lies for children" means
very much that it is merely a simplification.  Every simplification is a lie.
You have to distort the truth in some way to make it simpler.

This is done with the best intentions, and the understanding is that
next year, when the child is a little older, you will contradict that lie
with another lie that is a little closer to the truth.  Trying to start with
"the Truth" is impossible because:

1) You don't know the Truth either, just a much higher-order lie.
2) Your pupil can't handle the Truth yet.

This has more to do with the nature of Truth than with the ethics
of teaching, you see. ;-)

Certainly, I have this understanding of how science is taught. This
is why I really, really hate "true-false" tests. Because, while they
may be easy for people who rely only on the knowledge learned in
class, they are extremely hard for people who learn on their own ---
which bit of the truth am I not supposed to know, I ask myself.

For example, is the statement "Viruses are made of DNA" true, or
false?

In high school, the answer might be "true", but in college it is
certainly "false", because some viruses are made of RNA, and most
are also made of protein, and even a few have a membrane or
"envelope" analogous to a cell.

Virtually everything is more complicated when you look at it closely.

For example, consider these statements:

"The Earth goes around the Sun"

No, actually the Sun, Earth, and all the rest of the planets go around
something called the "barycenter" or "center of gravity" of the whole
solar system.  Now, since more than 99% of the mass in the Solar
System is in the Sun, that's pretty close to the Sun, but it isn't quite.
In fact, IIRC, it isn't even inside of the photosphere, due to Jupiter
being so massive.

"The Moon orbits the Earth"

See above, although the barycenter is beneath the Earth's crust. But,
more importantly, the Moon is only "loosely bound" to the Earth, it
never actually goes backward relative to the Earth-Moon orbit around
the Sun, and if the Earth were, say, destroyed to make way for a 
hyperspace bypass, the Moon would settle pretty happily into almost
the same orbit as the Earth has now. In fact, the Moon isn't a moon,
the Earth-Luna system is really a binary planet. *Moons* are what
Mars and Jupiter have (for example).

"Plants consume CO2 and make O2"

Well, yes, but they also consume O2, just like animals.  *On balance*,
the statement is *usually* true.  But most plants would probably
die in a pure-CO2 environment (unless they can drive the atmosphere
to a better composition fast enough).

And as for the subject line, I'd say the Python list is very much
at high-tide here. ;-)

--
Terry Hancock ( hancock at anansispaceworks.com )
Anansi Spaceworks  http://www.anansispaceworks.com