For centuries Aristotelian philosophy dominated human thought. Scientific questions were answered through reasoning and debate, rather than through experiments. For example, it was believed that heavy bodies fall faster than light ones, but we have no record from those days of an attempt to study the motion of falling bodies.

It was Galileo Galilei (1564 – 1642) who changed this way of thinking. He believed that nature’s truths must be discovered by observation and testing – not by argument alone. Through simple yet brilliant experiments, Galileo laid the foundation for what we now call the Scientific Method – a systematic way of asking questions, forming hypotheses, and testing them through evidence.

In this activity, you will learn how Galileo’s curiosity and experiments helped overturn long-held beliefs and opened the door to scientific thinking.