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6. What is red shift?

  • The expansion of the universe.
  • When a star is moving away from you then because the wavelengths coming from it are longer.
  • When a police siren comes towards you it appears to be higher and when it passes you it appears to be lower in pitch.

7. What is dark energy?

  • The "driving force" pushing the universe out. The proposed theory as to why the universes expansion is speeding up.
  • The material at the centre of galaxies
  • the matter in galaxies that we can not see. Causing spiral galaxies to rotate faster than we predicted.

8. Background radiation is radiation left over from the big bang. First detected accidentally in 1964 by Wilson and Penzias.

  • True
  • False

9. What is retrograde motion?

  • The orbit of a moon against a planet.
  • When a planets path changes direction and for a time moves backwards relative to the stars. Due to the fact the planets orbit at different speeds.
  • The motion whereby at the peak of a pendulums swing gravity brings it back downwards.
  • The model of the universe whereby all celestial bodies orbit a centre of mass at the centre of each galaxy.
  • The motion by which neptune appeared to "wobble" in its orbit; which led to the prediction of another planet outside it.