Grand unification epoch
Grand unification epoch Between 10 −43 seconds and 10 −36 seconds after the Big Bang Main article: Grand unification epoch As the universe expanded and cooled, it crossed transition temperatures at which forces separated from each other. These phase transitions can be visualised as similar to condensation and freezing phase transitions of ordinary matter. At certain temperatures/energies, water molecules change their behaviour and structure, and they will behave completely differently. Like steam turning to water, the fields which define our universe's fundamental forces and particles also completely change their behaviors and structures when the temperature/energy falls below a certain point. This is not apparent in everyday life, because it only happens at far higher temperatures than we usually see in our present universe. These phase transitions in the universe's fundamental forces are believed to be caused by a phenomenon of quantum fields called " sy