This key facts covers Key Facts within Red Shift & Big Bang for GCSE Physics. Revise Red Shift & Big Bang in Space Physics for GCSE Physics with 13 exam-style questions and 12 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 8 of 14 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
📋 Key Facts
- Light from distant galaxies is red-shifted — wavelength has increased
- Red shift shows galaxies are moving away from us
- The greater the distance, the greater the red shift (and recession speed)
- The universe is approximately 13.8 billion years old
- The Big Bang was not an explosion in space — it was the creation of space
- The CMBR is detected at 2.7 K from all directions
- CMBR was predicted before it was discovered — very strong scientific evidence
- Space itself is expanding — galaxies are not moving through space, they are carried with space
- The Andromeda Galaxy is blue-shifted (moving towards us) — part of our local group
- Most galaxies beyond the local group are red-shifted — the universe is expanding everywhere
Practice questions for Red Shift & Big Bang
What is the orbital period of a geostationary satellite?
Explain why a geostationary satellite stays above the same point on Earth's surface.
Quick recall flashcards
What is blue shift?
When a light source moves towards you, waves are compressed, shifting towards the blue end of the spectrum
What is red shift?
When a light source moves away from you, light waves are stretched to longer wavelengths, shifting towards the red end of the spectrum