The theory of epicycles very accurately explained observed phenomena, and though the conditions for science at that time were very different, its popularity and accuracy very much comparable to those of quantum theory.
In the Hipparchian and Ptolemaic systems of astronomy, the epicycle (from Ancient Greek: ἐπίκυκλος, literally upon the circle, meaning circle moving on another circle[1]) was a geometric model used to explain the variations in speed and direction of the apparent motion of the Moon, Sun, and planets. In particular it explained the apparent retrograde motion of the five planets known at the time. Secondarily, it also explained changes in the apparent distances of the planets from the Earth.
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Epicycles worked very well and were highly accurate, because, as Fourier analysis later showed, any smooth curve can be approximated to arbitrary accuracy with a sufficient number of epicycles. However, they fell out of favour with the discovery that planetary motions were largely elliptical from a heliocentric frame of reference, which led to the discovery that gravity obeying a simple inverse square law could better explain all planetary motions.
So the epicycles worked very well to explain and predict observations, but for reasons irrelevant to what really caused the motion of the planets. It's still possible that quantum mechanics will fall in the same way.
Note I don't have a horse in this race. I have no opinion on whether quantum mechanics is right or wrong.
In the Hipparchian and Ptolemaic systems of astronomy, the epicycle (from Ancient Greek: ἐπίκυκλος, literally upon the circle, meaning circle moving on another circle[1]) was a geometric model used to explain the variations in speed and direction of the apparent motion of the Moon, Sun, and planets. In particular it explained the apparent retrograde motion of the five planets known at the time. Secondarily, it also explained changes in the apparent distances of the planets from the Earth.
(...)
Epicycles worked very well and were highly accurate, because, as Fourier analysis later showed, any smooth curve can be approximated to arbitrary accuracy with a sufficient number of epicycles. However, they fell out of favour with the discovery that planetary motions were largely elliptical from a heliocentric frame of reference, which led to the discovery that gravity obeying a simple inverse square law could better explain all planetary motions.
https://en.wikipedia.org/wiki/Deferent_and_epicycle
So the epicycles worked very well to explain and predict observations, but for reasons irrelevant to what really caused the motion of the planets. It's still possible that quantum mechanics will fall in the same way.
Note I don't have a horse in this race. I have no opinion on whether quantum mechanics is right or wrong.