1. Scientific Theory on Origin of Universe
The Big Bang
Scientific Theory on Origin of Universe
A huge explosion c15 billion years ago caused the creation of time, space and a Universe which is constantly expanding

2. Evidence for the Big Bang
Based on Einstein’s Theory of Relativity (1915)
Edwin Hubble suggests galaxies are moving away from each other, based on changes in light given off by an object – ‘redshift’(1929)
Scientists hypothesised ‘cosmic microwave background radiation’ from the explosion could still exist. Detected in 1965
Recent research shows helium, hydrogen and other elements in known universe conform to proportions expected if Big Bang had occurred.
Quantum physics : calculations show matter in universe is moving apart at a known rate

3. The Big Bang
Microseconds after the explosion the universe expanded at an enormous rate. This rate then slowed to its current level. As it expanded it cooled, protons quickly formed and mixed with neutrons to form basic elements.
Star stuff emerged from the explosion and over billions of years evolved into the universe we know today.
The first stars formed at the centres of the vast, swirling clouds of gas and dust. Galaxies began to take shape. Scientists estimate that 125 billion galaxies exist in the known Universe. All the stars visible to the naked eye from Earth belong to the Milky Way galaxy. Our sun is just one of these stars.

4. Strengths of Big Bang Theory
An entirely scientific account of the origins of universe
No need for faith/god
Based on reasoned thinking about evidence which can be tested and measured
Does not necessarily discount God - compatible

5. Weakness of Big Bang Theory
Theory – not fact! History of science shows changes happen and ideas ultimately are rejected in favour of new ones
Distinguished scientists can make mistakes, or fit evidence with their ideas (bias) and present as fact
Many questions remain – What existed before? Will universe go on expanding infinitely?
Gaps in knowledge – tells us how but not why!