Download presentation
Presentation is loading. Please wait.
1
3.1 Cosmic Distance Ladder
2
From these methods: Determine distance (see p 615 including Fig 20.16)
3
From these methods: Determine distance (see p 626 including Fig 20.16)
5
Given luminosity infer distance (see p 626 including Fig 20.16) Use surface temperature of “main sequence stars” to infer Luminosity.
6
Use pulsation period of variable starts (“Cepheids”) to infer luminosity Given luminosity infer distance (see p 626 including Fig 20.16)
7
Use “Tully-Fisher relation” to infer galaxy luminosity from rotation speed
8
Given luminosity infer distance (see p 626 including Fig 20.16) Use “Tully-Fisher relation” to infer galaxy luminosity from rotation speed
9
From these methods: Determine distance (see p 641)
10
3.2 The Redshift
11
Fig 20.15 A redshifted galaxy spectrum Redshift: For small z
12
3.3 The Hubble law
13
Putting together info about speed v and distance d reveals remarkably simple behavior: Km/Sec/Megaparsec 1 Megaparsec = 3.3 million lightyears
14
Special feature of the Hubble law: It looks the same from any position:
15
The Big Bang
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.