Cosmology Practice Questions

As the fire engine moves towards the student, which row of the table describes the sound waves that the student hears?

	observed frequency	observed wavelength
A	higher	shorter
B	higher	longer
C	lower	shorter
D	lower	longer

The fire engine passes the student and moves away. State what happens to the wavelength of the sound observed by the student.

State the part of the electromagnetic spectrum that CMB radiation belongs to.

State the directions in space from which CMB radiation is detected.

Which theory of the origin of the Universe is supported by the existence of CMB radiation?

A the Steady State theory only

B the Big Bang theory only

C both theories equally

D neither theory

State one advantage of observing the Universe with an optical telescope rather than with the naked eye.

Other than visible light, name one type of electromagnetic radiation that telescopes use to observe objects in the Universe.

Describe the relationship between the red-shift of a galaxy and its distance from Earth, as shown by the data.

Galaxy T is 450 million light years from Earth. Use the data to estimate the red-shift of galaxy T.

Explain what these results suggest about the Universe.

Use the diagram to describe how the spectrum from the distant galaxy differs from the spectrum from the hydrogen lamp.

The red-shift $z$ is given by the equation

$$z = \frac{(\lambda_g - \lambda_o)}{\lambda_o}$$

Calculate the red-shift of the light from this galaxy.

The light from a second galaxy has a red-shift of $0.12$. State which of the two galaxies is further from Earth and give a reason for your answer.

State one idea about the Universe that is the same in both the Big Bang theory and the Steady State theory.

Explain how each theory accounts for the red-shift of light from distant galaxies.

Describe one way in which methods of observing the Universe have changed since the time of the first optical telescopes.

Explain why some telescopes are placed outside the Earth's atmosphere.

State what CMB radiation is.

Explain why the CMB radiation can be explained by the Big Bang theory but not by the Steady State theory.

State which theory of the origin of the Universe is currently accepted by scientists, and give the reason why.

The Big Bang theory and the Steady State theory are two theories of the origin of the Universe.

Compare the two theories and explain why the Big Bang theory is the model that scientists currently accept.

In your answer you should refer to red-shift and to CMB radiation.

Explain what a blue-shift in the light from the Andromeda galaxy tells astronomers about its motion.

A student says:

"Galaxies in every direction are moving away from us, so the Earth must be at the centre of the Universe."

Explain why the student is wrong.