Redshift & Hubble's Law
Calculate the distance to a far-away galaxy based on its observed redshift (z) using Hubble's Law.
Example: A redshift of 0.1 is common for nearby galaxy clusters.
Hubble's Law
Hubble's Law is the observation in physical cosmology that galaxies are moving away from the Earth at velocities proportional to their distance.
Understanding Redshift
Redshift occurs when the light from an object is increased in wavelength, or shifted to the red end of the spectrum. In cosmology, this is primarily due to the expansion of space itself stretching the light as it travels.
Frequently Asked Questions (FAQ)
What is the Hubble Constant?
The Hubble Constant (H₀) represents the current expansion rate of the universe. Estimates vary between 67 and 73 km/s/Mpc.
Does redshift mean galaxies are moving through space?
Partially, but on large scales, it is mostly due to the space between galaxies expanding, rather than the galaxies moving "through" a fixed space.