Devarim (04:06) Keep therefore and do them; for this is your wisdom and your understanding in the sight of the nations, who, when they shall hear all these statutes, shall say, Surely this great nation is a wise and understanding people.
What is this wisdom which is required to impress goyim?
Rashi in Chumash says it is Torah study
ושמרתם AND YE SHALL BE ON THE WATCH TO DO — This refers to the study of the laws (Sifrei Devarim 58),
ועשיתם — this must be explained according to what it implies: AND YE SHALL DO.
כי היא חכמתכם ובינתכם וגו׳ FOR THIS IS YOUR WISDOM AND UNDERSTANDING [IN THE EYES OF THE PEOPLES] — i.e. through this ye will be accounted wise and understanding men in the eyes of the peoples.
However in Shabbos (75a) Rabbi Shimon ben Pazi said that Rabbi Yehoshua ben Levi said in the name of bar Kappara: Anyone who knows how to calculate astronomical seasons and the movement of constellations and does not do so, the verse says about him: “They do not take notice of the work of God, and they do not see His handiwork” (Isaiah 5:12). And Rabbi Shmuel bar Naḥmani said that Rabbi Yoḥanan said: From where is it derived that there is a mitzva incumbent upon a person to calculate astronomical seasons and the movement of constellations? As it was stated: “And you shall guard and perform, for it is your wisdom and understanding in the eyes of the nations” (Deuteronomy 4:6). What wisdom and understanding is there in the Torah that is in the eyes of the nations, i.e., appreciated and recognized by all? You must say: This is the calculation of astronomical seasons and the movement of constellations, as the calculation of experts is witnessed by all.
Rashi (Shabbos 75a) In the eyes of the nations – since this is wisdom that is self evident in that it shows them a sign according to his words in the movement of the sun and the constellations, which testifies as he says that this year is rainy or this year is sunny All the events are related only to the mechanical movement of the sun and the constellations
It indicates it is referring to scientific studies. There Rashi indicates it is to knowledge that shows that nature follows mechanical rules and this undermines the belief that there are volitional forces that run the world