Evidence for the Big Bang Theory The evolution of the Universe can be compared to a display of fireworks that has just ended: some few wisps, ashes and smoke. Standing on a cooled cinder, we see the slow fading of the suns, and we try to recall the vanished brilliance of the origin of the worlds. ~ Abbe George-Henri Lemaıtre

1. Universal expansion and Hubble’s Law In 1929, Edwin Hubble found evidence to support Lemaître's theory. He observed that other galaxies were moving away from us and each other. And, farthest galaxies were moving faster than the ones close to us Hubble’s Law: v = H0 x d

Red Shift Evidence of expansion: Red Shift Which is an example of the Doppler Effect

If an object is moving toward Earth, its wavelengths of light are compressed. causes the object to look more blue If an object is moving away from Earth, its wavelengths of light are stretched. Causes the object to look more red

Because all galaxies beyond the Local Group show a red shift, they must be moving away from Earth. If all galaxies outside the Local Group are moving away from Earth, then the entire universe must be expanding.

2. Cosmic Background radiation Discovered 1965 by Arno Penzias and Robert Wilson came from the first photons that that streamed through the universe which are now so stretched out (due to the universe’s expansion) that they are in the form of microwave energy. Tune your TV between the stations and about 1% of the static on the screen is the afterglow of the big bang.

Amount of radiation discovered matched predictions C.O.B.E satellite confirmed temperature variations in the Universe & that noise radiation (static) is evenly spread Stephen Hawkings described this as "the most important discovery of the century, if not of all time." Amount of radiation discovered matched predictions

3. Abundance of Light Elements In 1948, George Gamow proposed that during the first few minutes of the Big Bang, it could have been hot enough for nuclear fusion to occur.

Ralph Alpher and Robert Herman worked out the details & found that nuclear processes would produce just the right abundance of helium to match that seen in stars today.

4. Growth of Structure explains how the large-scale structures (stars, galaxies, gigantic super clusters of galaxies, & the voids between them) formed ~ 10,000 years after the Big Bang, the Universe cooled to the point that the gravitational energy was able to collect together matter. Observations made using tools such as satellites, telescopes, and computer modeling

References https://pseudoastro.wordpress.com/2009/03/18/defending-the-big-bang-the-four-pillars-of-the-modern-big-bang-theory/ https://www.youtube.com/watch?v=xtrYF_hxxUM http://www.rialto.k12.ca.us/eisenhower/