The essentials of the first law of motion were initially developed by which scientist?

The first law of motion, also known as the law of inertia, is fundamentally credited to Galileo Galilei. He was the first to articulate the concept that an object remains at rest or in uniform motion unless acted upon by an external force. This idea laid the groundwork for later developments in physics and was crucial for Isaac Newton, who formalized this principle in his three laws of motion in the 17th century.

Galileo's work on motion, particularly through his experiments with inclined planes and falling bodies, demonstrated that objects do not require a sustained force to keep moving, which was a significant departure from Aristotelian physics that suggested continuous force was necessary for motion. His insights allowed for a clearer understanding of how motion behaves in the absence of friction or other forces.

While Isaac Newton is more widely associated with the laws of motion, it was Galileo who provided the essential ideas that Newton expanded upon, thus marking Galileo's pivotal role in their development. This distinction highlights the importance of Galileo's contributions to the foundation of classical mechanics.