Re: Real World

[Leigh Palmer <palmer@sfu.ca>]

> Hi!
>   This is a suggestion of a new thread to talk about. The subject
> is the fact that real phenomena are, practically always, extremely
> complicated and not quite suitable for exact study. It is by
> disregarding a lot of details (correctly chosen by a good intuition)
> that a productive analysis is possible.

My goodness! What a shocking proposition. Short of saying that I am
not capable of predicting the future, I would like to protest this
statement as, well, wrong! Are you saying that tomorrow evening there
will *not* appear simultaneously on the face of Jupiter the shadows
of three galilean satellites? Seems this was predicted a long time
ago, long before the spacecraft Galileo got in there and (in
principle at least) perturbed the orbits of the principal players in
this scenario.

I submit that astronomical ephemerides are evidence that physics has
a firm grasp on real phenomena in many cases. The formation of those
shadows should be a good test of the validity of my claim.

>   As an introduction to this state of affairs I will pose a (funny)
> Challenge: I will perform a sinple tast{ and challenge that none of
> you will be able to repeat it. The task is the following:
>   I will take a piece of paper (say, a page of newspaper) and throw
> it, standing straight up, into the air. The paper will fall to the
> floor at some place and in some position, which we should determine
> precisely (taking, for example, a photo). I challenge that nobody can
> throw the paper so as to fall again on the same place and in the same
> position, exactly.

What an unsurprising prediction. Who is surprised who knows physics?

Leigh