What's out there?
A star's death by explosion.
What is a super nova?
When this process ended approximately 20 minutes after the Big Bang, the baryonic matter in the universe consisted of mostly Hydrogen, with small fractions of Helium, Deuterium, and Lithium.
What is nucleosynthesis?
"The recession velocity of distant galaxies is proportional to their distance from earth."
What is Hubble's law?
The time it takes our planet to complete one orbit.
What is a Year?
He discovered the moons of Jupiter.
Who is Galileo Galilei?
These are the names of the three satellites that have mapped the CMB intensity (temperature) across the whole sky with increasing resolution.
What are the COBE, WMAP and Planck sattelties?
This is the time, approximately 5 10-44s after the Big Bang, when we believe that our laws of physics become valid.
What is the Planck time?
We rely on this principle, summarised as 'on a sufficiently large scale, the universe is homogeneous and isotropic", to formulate the equations that govern the behaviour of the universe.
What is the cosmological principle?
This unit is defined as the distance between the Earth and the Sun.
What is an Astronomical Unit?
He discovered that most galaxies move away from us.
Who is Edwin Hubble?
The pulsation period of these types of stars is proportional to their luminosity.
What are Cepheid variable stars?
The era in the history of the universe when nuclei and electrons formed neutral atoms.
What is recombination?
( H2 - 8/3 πGρ) R2 = -kc2
What is the Friedmann equation?
The distance at which one astronomical unit subtends an angle of one arcsecond.
What is one Parsec?
She discovered the relation between Cepheid stars' luminosity and period.
Who is Henrietta Leavitt?
A cluster of approximately 54 galaxies, including the Milky way, which are gravitationally bound to each other.
What is the local group?
This process led to a universe with a 'flat' geometry.
What is Inflation?
R ~ t^(2/3)
How does the scale factor in a flat, matter dominated universe grow with time?
Six hydrogen atoms per cubic meter.
What is the critical density of the universe?
He was a priest and astronomer who first proposed that the universe is expanding and that it started in what we now call the "Big Bang".
Who is Georges Lemaître?
Our universe is currently dominated by this form of energy, which has negative pressure and tends to accelerate the expansion of the universe.
What is Dark Energy?
The imprint the earth's motion with respect to the CMB photons leaves in the CMB temperature map.
What is the dipole anisotropy?
A universe where Ω < 1.
What is a closed universe?
Approximately 70%, 30%, and 0%.
What are the density parameters of Dark Energy, Matter, and Radiation?
In 1978 they won the Noble prize "for their discovery of cosmic microwave background radiation".
Who are Arno Penzias and Robert Wilson?