Radiation Era
This first epoch of the universe lasted from 0 to 10-43 seconds, where all four forces were unified.
What is the Planck Epoch
Population III stars form during this epoch.
What is the Stellar Epoch?
This is the current dominant force of the universe, causing expansion to accelerate.
What is Dark Energy?
These are the two most abundant elements produced during Big Bang Nucleosynthesis.
What are Hydrogen and Helium?
This term describes seeing distant galaxies as they appeared millions or billions of years ago.
What is look-back time?
During this epoch, the universe expanded exponentially, growing from the size of an atom to the size of a grapefruit.
What is the Electroweak epoch (or Inflationary Epoch)?
The surface of last scattering.
What is the CMB?
Unlike gravity, Dark Energy exerts this type of pressure on the fabric of space.
What is Negative / Repulsive pressure (causes expansion)?
These are the fundamental building blocks of protons and neutrons.
What are quarks?
Because of the expansion of space, distant objects appear shifted toward this end of the electromagnetic spectrum.
What is redshift?
In this epoch, the first protons and neutrons were formed from the quark-gluon plasma.
What is the Hadron Epoch?
Time after the big bang that sun-like stars began to form.
What is 5 billion years? (Galactic Epoch)
Two main theories about what dark energy is.
What are WIMPs and MACHOs?
Particles that carry force.
What are bosons?
What is gravity, strong force, weak force and electromagnetic force?
The process by which energy becomes a particle and its antiparticle.
What is Pair production?
The process in which electrons first joined with nuclei to form neutral atoms.
What is Recombination?
Age of the Earth.
What is 4.5 billion years old?
The term for a particle made up of 2 or more quarks.
What are Hadrons?
This unit of distance is roughly 3.26 light-years.
What is a parsec?
The length of time big-bang nucleosynthesis occurred.
What is 17 minutes? (from 3-20 minutes after the Big Bang.)
In the Atomic Epoch, the universe became transparent, a process also known by this name.
What is Decoupling?
First appearance of modern humans.
What is 200-300 thousand years ago?
Two examples of leptons.
What are Neutrinos and electrons?
This value, approximately 70 km/s/Mpc, represents the rate of the universe's expansion.
What is Hubble's constant?