Braishis Rabbah 20:4:
A certain philosopher wished to know how long the gestation period of a snake was. When he saw two snakes having intercourse he trapped them in a vat and would feed them, watching to see when they would give birth. When the Zekeinim came to Rome, [the Romans] asked Rabban Gamliel how long the gestation period was and he could not answer them. When Rabbi Yehoshua met Rabban Gamliel he saw that his face was sickly looking [because he was unable to answer]... "The answer is seven years," said Rabbi Yehoshua... " A dog is a chaya temeiya and gives birth after 50 days, a beheima temieya gives birth after 12 months, and the snake is described in the pasuk as "more cursed than all animals and chayos of the field." Just as the beheima's gestation period is 7 times longer than the chaya's, so too the snake's gestation is 7 times longer than the beheima's, hence seven years... When the philosopher heard this he began to bang his head against the wall. He said, "All I have labored to discover in seven years this Chacham was able to give me with the flick of a reed."
The message of the Midrash lies not in the particulars of the case, but in the contrast between the methodology of the "philosopher" or scientist and the methodology of Chazal. Ramban in his essay "Torah Hashem Temima" (p. 158-159 in the Chavel edition) writes that the meaning of the story of "ma'aseh braishis" is hidden and he does not understand it. However, Chachamim did understand the parsha. They were able to intuit from it the order of creation, the measure of the world and knowledge of astronomy and the universe, the calculation of the molad and tekufos, and all sorts of other knowledge which is hinted at in the count of letters, gematriyos, and their secrets. R' Yehoshua's knowledge of a snake's gestation did not require seven years of laborious scientific experimentation to discover but was obtained from Torah alone, based on his interpretation of the pasuk "arur atah...".
Clearly not even every Tanna possessed such knowledge -- Rabban Gamliel did not know the answer to the philosopher's question and admitted as such. And we know that Tanaim and Amoraim tell us that they went to doctors, consulted gentile experts about farming, etc. But that does not mean that such knowledge is not inherent in the Torah and accessible to those who can decode its secrets.