SCIE 1920U Chapter 13: 13 The Birth of the Universe
Document Summary
The universe was so hot during the first few seconds after the big bang that photons could transform themselves into matter, and vice versa. The electron is a particle of matter, and the antielectron is a particle of antimatter. When an electron and an antielectron meet, they annihilate each other totally, transforming their mass-energy back into photon energy. Everything that happens in the universe today is governed by four distinct forces: gravity, the electromagnetic force, the strong force, and the weak force. The electromagnetic force, which depends on the electrical charge of a particle instead of its mass, is far stronger than gravity. It is therefore the dominant force between particles in atoms and molecules, responsible for all chemical and biological reactions. Positive and negative electrical charges cause the electromagnetic force to lose out to gravity on large scales, even though both forces decline with distance by an inverse square law.
