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Vesto Slipher
Vesto Slipher was the first to observe that almost all nebulas were moving away from Earth. This observation discredited the static universe model. -
Expansion of the Universe
Alexander Friedman was a Russian mathematician and was the first to predict the expansion of the universe. -
Developing the Theory
A Belgian priest named Georges Lemaître first suggested the big bang theory in the 1920s, when he theorized that the universe began from a single primordial atom. -
Red Shifts
Edwin Hubble was a graduate student of Vesto Slipher and created the law of redshifts. This law states that galaxies moving away from Earth demonstrate emission spectra that were toward the red wavelength. -
Steady State Theory
According to the Steady State theory; Fred Hoyle, Thomas Gold, and Hermann Bondi state that new matter is created as the universe expands. -
Steady State vs Big Bang
From around 1950 to 1965, the support for these theories was evenly divided however the Big Bang theory could explain both the formation and the observed abundances of hydrogen and helium, whereas the Steady State could explain how they were formed, but not why they should have the observed abundances. -
Cosmic Background Radiation
Radio astronomers Arno Penzias and Robert Wilson discovered Cosmic Microwave Background radiation at the temperature of 2.725 degrees Kelvin. This provided evidence that the big bang caused extreme heat that is still measurable. -
Cosmic Background Explorer
NASA launches the Cosmic Background Explorer to search for radiation in the universe. NASA mapped primordial hot and cold spots in the cosmic background radiation. These are related to the gravitational fields from the early universe. -
Astro 2
Astro-2 is launched out of Edward's Air Force base with the Hopkins Ultraviolet Telescope (HUT). Sent to take pictures of the chemical makeup of celestial objects this trip lasted 16 days and is the longest shuttle flight to date. This further improved our understanding of the composition of celestial bodies. -
Quasars
The discovery of Quasars supported the Big Bang theory and went against the Steady State theory. According to the Steady State Theory, these quasars should be found all throughout the galaxy, but they are only found on the outskirts which supports the Big Bang theory. -
Further Research
Planck a satellite, is led by the European Space Agency and was launched in 2009 for the reason of mapping background radiation. -
James Webb
The James Webb Space Telescope is a space telescope currently conducting infrared astronomy. As the largest optical telescope in space, it is equipped with high-resolution and high-sensitivity instruments, allowing it to view objects too old, distant, or faint for the Hubble Space Telescope