Which scientist built upon Copernicus' model to develop the modern definition of inertia?

The scientist who built upon Copernicus' model and contributed significantly to the development of the modern definition of inertia is Galileo. He is well-known for his experiments and observations that challenged the prevailing Aristotelian notions of motion. Galileo's work laid the groundwork for the concept of inertia, which describes the resistance of any physical object to any change in its motion. This idea was a fundamental shift in understanding motion and paved the way for Isaac Newton's formulation of the laws of motion, including the first law which explicitly defines inertia.

Galileo's studies, particularly his inclined plane experiments, demonstrated that objects in motion would remain in motion unless acted upon by an external force. This was a critical advancement that built upon Copernicus' heliocentric model by emphasizing the consistency and behavior of motion in a way that supported a more scientific approach to understanding the universe.