What is red-shift?
The colour of light that comes from stars that are nearby
The red filter used by astronomers to analyse the light from distant stars
The change in wavelength of light from a distant galaxy moving away from Earth
How many galaxies show a red-shift?
Zero
Only a few of the most distant galaxies
Nearly all galaxies
What does a larger red-shift indicate?
The galaxy has more stars
The galaxy is moving away faster
The star is about to explode in a supernova
Which major theory does the observation of red-shift support?
Theory of stellar evolution
The existence of galaxy clusters
The Big Bang theory
What is the basic idea of the Big Bang theory?
The Universe expanded from a single tiny point, starting about 13.8 billion years ago
The Universe will end in a giant dark energy explosion
The Solar System began when a protostar started nuclear fusion reactions
What feature is believed to be the thinly spread remains of energy released in the Big Bang?
Red-shift
Light energy
Cosmic microwave background radiation
Why do scientists believe in the Big Bang theory?
Its predictions are supported by observations
It was one of the first scientific ideas to explain the beginning of the Universe
They can see it happening in supernova explosions
Observations of which objects suggest that the Universe is expanding?
The Sun
Galaxies
Black holes
What temperature is the CMBR?
-270°C
0°C
270°C
How old is the Universe?
4,600 million years
400,000 years
13.8 billion years