GGR112H5 Lecture Notes - Lecture 3: Milky Way, Big Bang, Planetesimal
Document Summary
Topics to be covered today: the solar system, sun, and earth, solar energy: from sun to earth, the seasons. The solar system, sun and earth: solar system formation, gravity, planetesimal hypothesis, dimensions and distances, speed of light, earth(cid:859)s or(cid:271)it. Solar system formation and structure: big bang - all matter in the universe can be traced back to a single point of origin. Rapid outward expansion of the universe began ca. Formation of the basic particles and elements, and first stars ensued ca. Big bang and the evolution of the universe: starting from one single point (left side, no understanding the scale of difference. Milky way galaxy: 100,000 light years across, >200 billion stars within. Our solar system: a lot of dust and particles still floating around space, most material has already reached planets. Solar energy: from sun to earth: electromagnetic spectrum of radiant energy, solar activity and solar wind intercepted energy at the top of the atmosphere.