Lecture 29 Cosmology - 300 Mpc cube ~ 100000 galaxies...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 29: Cosmology Hubble compared the distances he measured for galaxies with their Doppler shift of spectral  lines. - Further = higher velocity away - Galaxies are red shifted V = H0 d -> hubbles law H0 = 70 km/sec/Mpc Mpc= megaparsec Redshift Z = (L –L0)/L0 where L0 = rest wavelength At low velocity z ~ v/c  Cosmology  is the study of the structure and evolution of the universe. On every scale observed so far the universe shows structure:  o stars form star clusters and galaxies  o galaxies form galaxy clusters and superclusters, and other large structures  Big Structures 200 MPC have been seen Some distant stuff are 4000 MPC
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 300 Mpc cube ~ 100000 galaxies Universe has about 125-150 galaxies Two assumptions: 1) Universe is smooth 2) The same in every direction Universe has no center Olberss Paradox If universe is infinite with uniform density, the sky should be bright-Universe is not infinite because it has finite age-Universe changes with time According to Hubbles law, at one point galaxies were on top of each other. T = d/v = 1/H0 If H0 = 100 km/sec/Mpc Then t = 10^10 years The Big Bang-Big Bang was not explosion in an empty universe-Big Bang is the entire universe exploding-Everything happened at the same time If we look back we see back in time...
View Full Document

Page1 / 2

Lecture 29 Cosmology - 300 Mpc cube ~ 100000 galaxies...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online