All About the Big Bang

By: Jill Garcelon

What It Is

The Big Bang Theory is a theory on how the universe was created. The theory is that the universe all started with a small singularity, then inflating over the next roughly 13.8 billion years to the universe as we know it today.

In Detail

Gamow's Evolutionary Theory of the Universe says a stew of super-hot nuclear fusions of basic particles created all the hydrogen in the Universe in one explosive moment. The same blast caused space to expand.

Evidence

Red Shift

Astronomers use a spectroscope to view galaxies. They use it to record the spectral lines that are shown as dark lines on the visible spectrum. Astronomers found out that red shift was in nearly all the galaxies' spectral lines. What is redshift? Astronomers use spectral lines to determine if an object is move toward or away from an observer. If the spectral lines are toward the red end of the spectrum, then they are moving away. This occurrence is called redshift. Knowing that most galaxies are moving away means our universe is still expanding which helps show the universe is still expanding as it had with the Big Bang Theory.

Hubble's Law Summary

Hubble's law summarized is a statement of correlation between the distance to a galaxy and it's red shift.

Left Over Radiation from Big Bang

This is cosmic background radiation left over from the Big Bang. Cosmic background radiation is left over radiation from the big bang.
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How the Universe Changed After the Big Bang

Expansion at a Slower Rate

According to NASA, after inflation the growth of the universe continued, but at a slower rate. As space expanded, the universe cooled and matter formed.

Predictions for the Future

My Prediction, As Well As Others

My prediction is that the universe will keep expanding on and on until at one point, it comes to a stop. There are other predictions, such as the Big Crunch and the Eternal Universe.

The Big Crunch

If there is enough matter in the Universe eventually gravitational forces will stop its expansion. When this happens gravity will cause the universe to reverse its direction and begin to collapse under its own weight. This phase of the Universe's life is known as the Big Crunch.

The Eternal Universe

If the universe does not contain enough matter to stop its expansion it will continue to expand forever. Using the currently understood laws of physics we can project into the future what the Universe may look like in very distant eras. Two astrophysicists at the University of Michigan have outlined the future history of the Universe. They have divided the future into Eras. The current Era is known as the Stelliferous or Star-Filled era. The next era is known as the Degenerate era. The era after that is the Black Hole era because black holes will be the only gravitationally important objects left in the universe. After that the Universe shall be composed of only radiation and particles which have an infinite lifetime.

Cited Sources