What is it?• 1948. Hermann Bondi, Thomas Gold and Fred Hoyle.• Other models of cosmology besides the Big Bang theory• One of them was the Steady-State Model• General character of the universe is NOT changing over time: – Universe looks the same from everywhere – It has always looked like this – Universe is uniform in both time and space – No beginning or no end of the universe – Rejects the idea of Big Bang Theory – Expansion was explained as follows (red shift): matter is being created out of nothing about a few atoms per cubic mile per year – So,even though there is expansion, density remains the same
Why did people believe in this theory?• Offered simple solutions to the way the universe worked• Predictions based on this theory agreed with Einstein’s theory of relativity.
Why do people no longer believe this theory?• Scientists began looking at early eras of the universe and began seeing contradictions to this theorydifferences between how it is now and how it was back then.• Scientists showed that universe exploded in its creationthe heat and the glow that exists in the universe now.• Astronomers eventually found out that the universe is evolving over time. – For example: there were types of stars that were famous in certain period in the known history of the universe – Cosmic Microwave Background Radiation proved it wrongradio telescopes show glows in certain areas of the universe that belongs to microwave region of radio spectrum. It is left over from early stages of the development of the universe.
Refined Versions• It is irrelevant to science now because it has been proven wrong. However, it is good to know it in order to understand the refined version of it.• This theory led to its refined version: the Big Bang Theory. This was the result of experiments and scientific evidence. While scientists and astronomers tried proving the Steady-state theory, they disproved it but they proved another theory called the Big Bang Theory and the universe expanding forever.• There are, however, still questions whether the Steady-State Theory and the Big Bang Theory can be combined since both agree on expansion.