The Big Bang

Question 1

Describe the Steady State theory

Answer 1

The Steady State theory says that the
universe has always existed but is
expanding and creating matter to
counteract the loss in density.

Question 2

Describe the Big Bang theory

Answer 2

The Big Bang theory states that the
universe expanded from a very small
dense point about 14 billion years ago.

Question 3

What is red-shift?

Answer 3

A perceived increase in the wavelength
of light due to the source moving away
from the observer

Question 4

What does red-shift provide evidence for?

Answer 4

● The universe is expanding

● This supports the Big Bang theory

Question 5

What does the Big Bang theory suggest?

Answer 5

The entire universe started from a very

small, hot and dense region in space

Question 6

Compare the observed red-shift of two galaxies, one

further away than the other

Answer 6

● The galaxy that is further away is
travelling faster
● The observed red-shift is greater the
further away it is

Question 7

What did scientists observe to provide evidence that

the universe is expanding at an ever faster rate?

Answer 7

They observed supernovae, which
suggested that galaxies are moving
away at an ever faster rate

Question 8

Prior to observations of supernovae, what was
believed about the rate of expansion of the universe
and why?

Answer 8

● The rate of expansion was expected to
occur more slowly
● It was thought that gravitational forces
would cause this slowing down

Question 9

What does CMBR stand for?

Answer 9

Cosmic Microwave Background

Radiation

Question 10

What does CMBR provide further evidence for?

Answer 10

● The Big Bang Theory
● It is believed that CMBR originates
from radiation produced in the big
bang

Question 11

How does the existence of CMBR support the

expansion of the universe?

Answer 11

● It is thought that gamma radiation was
released in the Big Bang
● The expansion of the universe has
stretched this radiation, resulting in the
microwave radiation present today