What is Gravity Really?
Gravity has played a big part in making the universe the way it is. Gravity is what makes pieces of matter clump together into planets, moons, and stars. Gravity is what makes the planets orbit the stars–like Earth orbits our star, the Sun. Gravity is what makes the stars clump together in huge, swirling galaxies. Another great scientist, Albert Einstein, who lived in the 20th century, had a new idea about gravity. He thought that gravity is what happens when space itself is curved or warped around a mass, such as a star or a planet. Thus, a star or planet would cause kind of a dip in space so that any other object that came too near would tend to fall into the dip. This 2-D animation gives an idea of how gravity works in 3-D.
