NATS 1880 Lecture 5: Chapter 3

• School: York University
• Department: Natural Science
• Course: NATS 1880
• Professor: Paul Delaney

Document Summary

All of the matter and energy in existence. Matter that you would recognize (planets, stars, etc. ) Dark matter cannot be seen but does have a gravitational influence; 28 %| Dark energy (vacuum energy) cannot be seen but manifests itself as a repulsive force: 68% Observational evidence supports strongly that the universe was once compressed into a very hot, very dense point and that since that time the universe has continued to expand. Galaxy motion is (by and large) away from the milky way in all directions. Galaxies moving away from each other because they are actually not moving -> the whole space is stretching, so the distance between galaxies started increasing. Whole universe expanded faster than the speed of light at one point. The cosmic microwave (cid:271)a(cid:272)kg(cid:396)ou(cid:374)d (cid:396)adiatio(cid:374) is the left o(cid:448)e(cid:396) (cid:862)e(cid:272)ho(cid:863) of the u(cid:374)i(cid:448)e(cid:396)se"s hot beginnings. The distribution of the chemical elements has changed with time, notably h and he initially and now many more (heavier) elements.