Universe

Key Stage 3

Meaning

This image shows a tiny fraction of the Universe containing many galaxies.

The Universe is everything that exists.

About the Universe

The Universe has over 200 billion galaxies.

The Universe is around 13.7 billion Earth years old.

Everything that has ever happened and ever will happen will all take place in the Universe.

Key Stage 4

Meaning

The Universe is everything that exists.

About the Universe

The Universe has over 200 billion galaxies.

The Universe is around 13.7 billion Earth years old.

Everything that has ever happened and ever will happen will all take place in the Universe.

Origin of the Universe

Big Bang Theory

The current prevailing theory for the origin of the modern universe is the Big Bang Theory backed by evidence which shows all the observed galaxies in the universe must have all begun at one small point in space.

Evidence:

Redshift - Redshift shows that all of the galaxies are moving away from each other at very high speed.

Cosmic Microwave Background - Microwave radiation coming from all directions in space show that at one point the entire universe was roughly the same temperature everywhere.

Old Stars - There have not been any stars observed older than 13 billion years.

Steady State Theory

An abandoned theory was the Steady State Theory which suggested the universe never had a beginning. It was always here. It was suggested that as the galaxies move apart from one another, new galaxies would come into existence to fill the gaps.

Evidence:

Redshift - Redshift shows that all of the galaxies are moving away from each other at very high speed.

Future of the Universe

Current evidence shows the galaxies are accelerating away from us suggesting the universe will continue to expand forever.

Some scientists used to believe the universe would end with all the matter falling back together. The theory was called 'The Big Crunch' but it seems unlikely to be true due to the counter evidence.