There are, of course ways we can measure progress. E.g. by measuring the results of applying science and scientific results to practical problems. Since we talk about medical sciences here, life expectancy is a good measure. So is being able to cure specific classes of diseases. And these are off the top of my head, I'm pretty sure someone into the philosophy of science could come up with much better and more general metrics.
> At the time of Galileo, scientists had, after many centuries, perfected their means of calculating geocentric orbits.
Again, Galileo had a clash with the catholic church not really fellow scientists.
> Thee equations worked extremely well.
I'm not so sure. Galileo came up with his theory based on what geo-centric view couldn't explain.
> Experts at the time would have told you that science had progressed significantly since the time of Aristotle.
> Yet it had progressed in a completely wrong direction.
Which was true. They indeed got ahead, because they also had to perfect the math and measurements, etc. Not just the descriptions of the orbits. Also, BTW, Galileo was wrong. He thought the Sun was the center of the freaking universe, which it isn't at all.
Also what are you then arguing for? If you can't say that science evolves and improves over time then what's wrong with censorship? Those ideas that you think would be censored (I didn't exactly say that, but let's go with it for now) would not improve science. Or, at least we wouldn't be able to measure it, according to you.
The way I like to think about it is that science is a machinery that constantly builds and improves itself. It not only gets 'bigger' but it constantly gets better and building itself by improving the scientific method itself. E.g. if you think about medical sciences again, 150 years ago doctors would experiment on themselves (n=1) and use their "experience" (i.e. a small amount of inaccurate measurements aggregated in their head). These days we do double blinded, randomized controlled trials and funky statistic checks to filter out errors, then other people look over the results multiple times (think peer reviews and meta-analysises). It's an iterative process that keeps correcting and perfecting itself. And we do know when we go in the wrong directions because results will be off from the reality.