The ‘steady state’ theory was once a popular alternative to the ‘big bang’ theory.

The ‘steady state’ theory suggested that the universe, although expanding, had no origin and it has always existed. As the universe expands, a small amount of matter is created to keep the universe looking exactly the same all of the time.

(a) When considering the origin of the universe, what is the difference between the ‘big bang’ theory and the ‘steady state’ theory?

(2 marks)

(b) The light from distant galaxies shows a red-shift.

(i) What is red-shift ?

(1 mark)

(ii) Why does red-shift provide evidence to support both the ‘big-bang’ theory and the ‘steady state’ theory?

(2 marks)

(c) The ‘steady state’ theory was important in encouraging new research into the universe.

Suggest a reason why scientists were keen to carry out new research.

(1 mark)

(d) Scientists can answer many questions about the universe, but not the question:

‘Why was the universe created?’

Suggest a reason why this question cannot be answered by scientists.

(1 mark)

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From Q6 P1 AQA January 2008