NATS 1740 Chapter Notes - Chapter 22: Electroweak Interaction, Planck Units, Nucleosynthesis

• School: York University
• Department: Natural Science
• Course: NATS 1740
• Professor: Tatiana Paulin

Document Summary

Big bang theory- theory of the universe"s earliest moments, stating that the observable universe came into being at a single moment in time. The universe is cooling with time as it expands, therefore it was hotter in the past. Planck era- the first era after the big bang. The gut era- era when only gravity and the gut force operated. Inflation- a sudden expansion of the universe thought to have occurred at the end of the gut era. The electroweak era- gravity, strong force, and electroweak force operated. Particle era- subatomic particles were continually created and destroyed. Nucleosynthesis era- all neutrons and 1/7 of protons had fused into helium. Era of nuclei- matter was fully ionized and opaque to light. Era of atoms and galaxies- cool enough for neutral atoms to form. Galaxies began to form when the universe was 1 billion years old. Cosmic microwave background- remnant radiation from the big bang.