Almost learned

Some say it’s just a theory, that proof is never shown
If all is just statistics then the truth is never known
Oh sure, you can experiment; the bottom line is this:
If we can’t know what’s real then a theory’s all it is

To make this claim’s to miss the point, for that’s not what we do
We live here in this universe, objectively true
But from our poor subjective home, there’s not far we can see
And so we do the best to learn what makes reality

We make up rules—and do they fit? That is the question here
We test to see if they make sense within our ecosphere
And if the rule foretells the truth much better than before
Then we accept it—not as truth!—and keep it in our store

The key thing is this all repeats, and old “truths” are discarded
We still respect the intellect of those who have departed
But rules assembled, all agree, can still be useful things
Refinèd with experiments, can give our airplanes wings

So no, my science is not truth; it’s models known as “theories”
Approximate reality for answers to our queries
We never quite will know what’s right but closer we will be
By learning and progressing we approach infinity.

Bonus SMBC comic:

"Evolution isn't a 'theory' in the common sense. Evolution is as well understood as the 'theory' of gravity." / "What the...are you saying we don't understand evolution?!"

Part of Poem-a-Day 2013. Title donated by Robert M.