The scientific knowledge of our sages.
Scientific facts in Chazal and rabbinic tradition can be divided into two categories:
(a) Scientific facts that are taken from the Torah itself, and
(b) Scientific facts that were known by Chazal based on their knowledge of science.
The most recent example of this is the Chazon Ish ZTL, who lived in our times, and had no secular education at all, yet showed much knowledge of math and astronomy, much of which can be seen in his teshuva on the international dateline.
(reposted from elsewhere)