Lilmos, TY. Actually some Geonim, Rishonim and Achronim do say that Chazal were wrong about scientific matters and others say that they were actually talking about the spiritual counterparts of the physical world (on this see “Did Chazal Know Science? (Rhetorical Question)” posted on-line by the Bet Midrash of Bayswater).
Sources:
Teshuvos HaGeonim 394:
Our sages were not doctors and said what they did based on experience with the diseases of their time. Therefore, there is no commandment to listen to the sages [regarding medical advice] because they only spoke from their opinion based on what they saw in their day.
*Rambam, Moreh Nevuchim 3:14:
*Rambam, Moreh Nevuchim 2:8:
It is one of the ancient beliefs, both among the philosophers and other people, that the motions of the spheres produced mighty and fearful sounds… This belief is also widespread in our nation. Thus our Sages describe the greatness of the sound produced by the sun in the daily circuit in its orbit. The same description could be given of all heavenly bodies. Aristotle, however, rejects this, and holds that they produce no sounds. You will find his opinion in the book The Heavens and the World (De Coelo). You must not find it strange that Aristotle differs here from the opinion of our Sages. The theory of the music of the spheres is connected with the theory of the motion of the stars in a fixed sphere, and our Sages have, in this astronomical question, abandoned their own theory in favour of the theory of others. Thus, it is distinctly stated, “The wise men of other nations have defeated the wise men of Israel.” It is quite right that our Sages have abandoned their own theory: for speculative matters every one treats according to the results of his own study, and every one accepts that which appears to him established by proof.
Rabbeinu Avraham ben HaRambam, Ma’amar al Derashos Chazal:
Maharam Schick, Teshuvas Maharam Schick 7
: Matters that were not received by Chazal as halachah leMoshe miSinai, but rather which they said according to their own reasoning – and with something that is not received [from Sinai] and has no root in our Torah, but rather comes from investigation and experience, it is difficult to determine [that it is true]. And there are many occasions when the sages determined, according to their own intellects, that a matter was a certain way, and the subsequent generation analyzed the matter further and disputed the earlier view.
* Regarding Rambam’s opinion, in his introduction to Perek Chelek he says that all of the aggadic statements are very deep metaphors.
Chazal themselves say that they deferred to gentile scientists (Pesachim 94b and Sanhedrin 5b).
However, either way you slice it we do not learn this-worldly scientific facts from the Gemara and midrashim. We learn how to conduct are lives in accordance with Halacha and ethical principles. According to all opinions, someone who wants to be a doctor goes to medical school. When Rav Hutner’s talmid muvchak, Rabbi Israel Kirzner, decided to become an economist he went to Brooklyn College and then NYU where he studied under Ludwig von Mises, who was an anti-religious Jew.