While he didn't get a precise numerical value, he was the first to:
* Demonstrate that all objects fall at the same rate, regardless of their mass, through his famous (and likely apocryphal) experiment at the Leaning Tower of Pisa.
* Develop the concept of acceleration and apply it to the motion of falling objects.
* Use inclined planes to slow down the motion of falling objects, allowing him to more accurately measure their acceleration.
However, it's important to note:
* Galileo's measurements weren't incredibly precise. He used crude methods and lacked accurate timekeeping devices.
* The first truly precise measurement of g was done by others. Later scientists like Christiaan Huygens and Isaac Newton refined the measurement, but it was Galileo who laid the groundwork.
So, while Galileo wasn't the first to get a precise numerical value, he was the first to conceive of and measure the concept of acceleration due to gravity.
