Velocity of a galaxy equation

Define standard candles

How to measure distance of nearby objects?

What are cepheid variables?

How to measure present day hubble parameter?

Simple estimate of universe age in a matter dominated universe

Accurate calculation of universe age

Why is an open matter-dominated universe older than a flat matter-dominated universe?

Why is an flat cosmological constant universe older than a flat matter-dominated universe?

What is the general observational limit on age of the universe?

Describe techniques to measure age of the universe

What is the Robertson Walker metric?

What is ds, dtheta, dphi, for light rays travelling radially?

Equation for red-shift of a wavelength

What is the cosmological horizon distance?

Equation for cosmological horizon distance in flat universe?

What is the cosmological event horizon?

Proper distance

Proper distance in a flat universe

Proper distance in a closed universe

Proper distance in an open universe

Luminosity distance

Luminosity distance in terms of z

Application of luminosity distance

Angular diameter distance

Example of standard ruler

Issue with angular diameter distance