What does it mean when a product is synthetic

What happened in 2012 and how does it illustrate the importance of understanding the sun and how it works?

Particles vibrate in a rigid structure and do not move relative to their neighbors.

The famous scientist galileo galilei did several experiments with sloping planes, which he rolled metal balls down so that he could study motion. by changing the slope, he could study how the speed at which the ball rolled was affected. what was the independent variable in galileo's experiment? a. the speed of the ball b. the slope of the plane c. whether the ball moved d. what the ball was made of