Why was experimentation important to Galileo Galilei’s scientific method?

Experimentation was central to Galileo Galilei’s scientific method because it allowed him to transform natural philosophy from a qualitative, verbal account into a rigorous, mathematical discipline. By insisting that the book of nature was written in the language of mathematics, Galileo established experimentation as a recognized and essential method for discovering the objective facts of the physical world.1

His reliance on empirical testing enabled him to challenge and eventually overturn long-standing Aristotelian doctrines. For example, through his experiments with falling bodies, he demonstrated that the speed of an object's fall is not proportional to its weight, contradicting traditional claims. Similarly, his use of the telescope provided observational evidence—such as the mountainous surface of the Moon and the phases of Venus—that fundamentally undermined established cosmological assumptions and supported the heliocentric system. Ultimately, Galileo’s commitment to experimentation ensured that scientific conclusions were grounded in observable reality rather than purely theoretical or philosophical tradition.123