Gravity and Relativity

Gravity and Relativity

Gravity is the pulling force that all matter and objects have - from a grain of sand to a supergiant star. Without gravity, our everyday world would fall apart and we would float away into space.

Gravity is one of the Universe's basic forces. Every speck of material or matter, from a single atom to a whole galaxy. has a gravitational force. This force attracts, or pulls towards it, all other objects and forms of matter.

The more atoms an object has, and the larger these atoms are, the greater its mass and its gravity. The further you get from an object, the weaker its gravitational pull.

Effects of gravity

Your body's gravity pulls objects towards you, but this gravity is too weak to notice in everyday life. Earth, however, is so big that we can't help but notice its gravitational pull. It pulls nearby objects so powerfully that they continue to stay on its surface. Earth's gravity extends into space and keeps satellites, spacecrafts and the Moon moving around it. The Sun's huge gravity holds all the plancts, including Earth, asteroids, comets and other objects in orbit around it.

Curved space

Scientists regard gravity as a result of space being bent, or curved. Space with no objects has straight lines, like graph paper. A massive object like a planet or star alters this and makes space curve towards it. A smaller approaching object follows the bent lines and moves towards the massive object. This is another way of saying that the massive object's gravity pulls the smaller object to it. The idea of curved space is part of Einstein's Theory of Relativity.

Fascinating Facts
• Time, space, size, mass and other features are relative - they change according to the position and speed of you.
• Gravity is the result of space as well as time being curved due to massive objects. Time slows down near a massive object.
• The faster you move, the slower the time passes.
• The faster you move, the shorter you get in the direction of the movement.
• Only the speed of light is not relative. This stays the same, or constant , everywhere in the Universe.