What is different with Python ?

[Roy Smith]

Steven D'Aprano <steve at REMOVEMEcyber.com.au> 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. If the 
> Earth was completely covered by ocean, the difference 
> between high and low tide would be about 10-14 inches. 

Yeah, I know about all that stuff.  But, let's explore this from a teaching 
point of view.

> 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.

That's a lot of detail to absorb, and is appropriate for a college-level 
course taken by oceanography majors.  The key to teaching something is to 
strip away all the details and try to get down to one nugget of truth with 
which you can lay a foundation upon which further learning can happen.

Yes, both the sun and the moon have gravitational fields which affect 
tides.  But the moon's gravitational field is much stronger than the sun's, 
so as a first-order approximation, we can ignore the sun.

And, yes, there's a huge amplifying effect caused by coastline shape and 
resonant frequencies of the ocean basins, but if you took away the moon 
(remember, we're ignoring the sun for now), there would be no tides at all.  
If you took away all the continents, there would still be tides, they would 
just be a lot less (and nobody would notice them!).

And, yes, wind affects tide.  I live at the western tip of Long Island 
Sound.  If the wind is blowing hard along the axis of the Sound for a solid 
day or two, I can see that it has a drastic effect on the tides.

This says to me that "The tides are created by the moon, amplified by the 
shapes of the land masses, and altered by the wind".

Sure, "the moon causes the tides" is not the whole picture, and from a 
quantitative point of view, may not even be the major player, but from a 
basic "How do I explain this physical process to a 6th grade child in a way 
that's both easy to understand and fundamentally correct", I think "the 
moon causes the tides" is the only reasonable explanation.  Once that basic 
idea is planted, all the other stuff can get layered on top to improve the 
understanding of how tides work.

So, to try and bring this back to the original point of this thread, which 
is that Python is a better first language than C, let's think of the moon 
as the "algorithms, data structures, and flow control" fundamentals of 
programming, and memory management as the continents and ocean basins.  
What you want to teach somebody on day one is the fundamentals.  Sure, 
there are cases where poor memory management can degrade performance to the 
point where it swamps all other effects, but it's still not the fundamental 
thing you're trying to teach to a new CS student.