Observation and Measurement
The change in wavelength as a result of the expansion of space.
What is the cosmological red shift?
The Huggins' used this device to show that distant stars were made from the same materials found on earth.
What is a spectrograph?
These kept the sun, moon, and planets in place, according to Aristoteles.
What are crystalline spheres?
These stellar events let us measure distances beyond our local group for the first time, and their Hubble diagram shows that the expansion of the universe is accelerating.
What are supernovae type 1A?
He introduced the 'dark energy' term in the equations to make a steady-state universe theoretically possible.
Who is Albert Einstein?
This region in the CMB temperature fluctuation power spectrum shows that the whole visible universe was once in thermal equilibrium.
What is the super-horizon region?
This infra-red survey of the whole sky catalogued 300 million objects, mostly distant galaxies.
What is the 2MASS infrared survey.
The name given to the idea that in an infinite, eternal universe filled homogeneously with stars, the night sky should be bright.
What is Olbers' Paradox?
Measurement of these ratios first lent credence to the Big Bang theory.
What the elemental abundances?
Though he was not an astronomer, he wrote the book "The Hitchhiker's Guide to the Galaxy".
Who is Douglas Adams?
The name of the effect that causes higher order peaks in the CMB power spectrum to be damped.
What is Silk damping?
This device on board the COBE satellite measured the CMB spectrum.
What is the Far Infrared Absolute Spectrophotometer (FIRAS)?
This hypothesis states that the universe has always had the same density, and is neither expanding nor contracting (or if expanding, matter is created to fill the new space).
What is the steady-state hypothesis?
The name of the sphere formed by the furthest distance from which light is currently reaching us.
What is the particle horizon?
They won the Noble Prize in physics in 2011 "for the discovery of the accelerating expansion of the Universe through distant supernovae".
Who are Saul Perlumtter, Brian Schmidt, and Adam Riess?
This property of the universe determines the height of the first peak in the CMB power spectrum.
What is the baryon content?
This is the type of telescope used by Friedrich Bessel to measure the parallax effect for the first time.
What is a split-image telescope?
This type of geometry is distinguished by the fact that for any line L and point P, one can always find at least two lines through P which are parallel to L.
What is a hyperbolic geometry?
Penzias and Wilson thought that the noise in their telescope was caused by this.
What are bird droppings?
He was one of the most vocal critics of the big bang theory, and coined the term 'Big Bang' as an attempt to belittle the idea.
Who is Fred Hoyle?
This feature in spectra of distant objects is caused by the electron transitions of neutral Hydrogen.
What is the Lyman-alpha forrest?
This device on board the COBE satellite mapped the infrared emission from foreground objects.
What is the Diffuse Infrared Background Experiment (DIBE)?
The idea that at a high enough energy, all the known forces are merged into a single force.
What is the Grand Unified Theory (GUT)?.
Thought to be the initial seeds of the temperature variation of the CMB.
What are quantum fluctuations?
He first measured the structure of our galaxy, using Cepheid stars to estimate distances. He believed our galaxy was the whole universe.
Who is Harlow Shapley?