Astronomy 2022A/B Lecture Notes - Lecture 2: Cosmic Distance Ladder, Friedmann Equations, Accelerating Expansion Of The Universe
Document Summary
Universe/cosmos is everything all space, matter and energy that is accessible to us. To date, everything ever observed in the universe is made either of matter or energy. Einstein says with e=mc2 that matter can turn into energy, and vice-versa. It may be stored or converted to different forms, but there is none that. Hydrogen fusion gets lost, nor is new created: h atoms contain just one proton, regular helium consists of two protons and two neutrons. Composition of stars: each element on periodic table absorbs a specific pattern of light colours, from the relative strength of absorption lines, one can infer the composition of stars. The doppler effect: the light of a moving source is blue/red shifted by an amount that increases with increasing velocity, does(cid:374)(cid:859)t (cid:272)ha(cid:374)ge the patte(cid:396)(cid:374) of li(cid:374)es see(cid:374) i(cid:374) spe(cid:272)t(cid:396)a, (cid:271)ut does shift the (cid:449)hole pattern.