Physics Lecture 25

Physics Lecture 25 - t = 10-34 seconds after Big Bang b....

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 25: Life, the Universe, and Everything Unified Theory X-boson m X = 10 17 MeV/c 2 I. The Expanding Universe and the Big Bang A. Evidence 1. Universe is expanding a. extrapolation of “original location” can be done 2. Background Radiation a. Early on i. Very hot – large collision energies Particles are created with mass such that E collision > mc 2 II. A. T~10 10 K-s 1/2 /√(t) 1. 1000K at 10 14 seconds B. Energy of Collisions much larger in the early universe 1. E ~ kT = 10 6 eV-s 1/2 a. Where k is the boltzman constant 2. example – when was the last time that the X bosons were easily made from collisions in the universe? (i.e. Strong, EM, and weak forces equal) a. energies needed E ~ 10 23 eV i.
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: t = 10-34 seconds after Big Bang b. energies needed for hydrogen to begin to be created i. t = 10 10 seconds after Big Bang III. Events in the Early Universe A. Depends on collision energies IV. Summary of Course A. Electrical forces 1. holds everyday objects together B. Strong Force 1. holds nuclei of atoms together C. Gravitational force 1. holds stars together D. Waves in general and EM waves in 1. Light and Sound E. Interference F. Wave-particle Duality 1. Quantized energies Temperature of early Universe T~10 10 K-s 1/2 /(t) Typical Collision energies E ~ kT = 10 6 eV-s 1/2 Minimum Collision energy to produce a particle with mass m E collision ~mc 2...
View Full Document

Ask a homework question - tutors are online