Tim Maroney writes
> > Approximate assertions, e.g., "the planets orbit the sun in ellipses"
> > should be taken as (a) true, and (b) a correct description of reality.
>
> Why?
Because (1) you cannot *say* how something moves, just as you
cannot *say* what something is (2) no description is completely
one-hundred percent accurate (3) we need to pack as much meaning
and truth into pronouncements as we economically can.
> There are solutions of general relativity in which the universe is
> moving around the earth and the earth is standing still. Saying that the
> planets orbit the sun in ellipses is saying that the sun's frame of
> reference is preferred to the earth's. This preference for one frame of
> reference is apparently subjective.
Language is used to communicate structure, ideas, and relationships.
It would be absurd to specify the intended frame of reference for
every statement. Likewise it would be absurd to have to say
"approximate ellipses" and "approximate orbits". Moreover, how
could one define "sun"? A hot ball of gas? But exactly what
molecules does that include, and when? And so on.
However, to get into the spirit of the thing, and point out how
your paragraph itself is not "totally accurate", would the
following be preferable?
> "I" think that there are formal mathematical results that are often
> called "solutions" of Albert Einstein's theory of general relativity
> in which the entire so-called universe "instantaneously" for some
> time t0 rotates about some point p0 inside the "Earth" and most of the
> particles of the Earth at t0 are moving only "infinitesimally"
> relative to all the other particles of the "Earth" and that the
> vast majority of those particles have a very small collective
> motion relative to p0.
Well... that was just the first sentence! But I hope you see my
point: even my amended version has a lot of ambiguous terms that
still require elaboration and qualification if the sentence were
to be 100% accurate.
Lee
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