This comparison covers Evidence for the Big Bang — Summary 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 6 of 14 in this topic. Use this comparison to connect the idea to the wider topic before moving on to questions and flashcards.
🚀 Evidence for the Big Bang — Summary
| Evidence | What it shows | Why it supports Big Bang |
|---|---|---|
| Red shift of galaxies | Galaxies moving away; more distant = faster recession | Universe is currently expanding — consistent with Big Bang origin |
| CMBR (2.7 K microwaves) | Faint microwave radiation from all directions | Predicted by Big Bang theory; the cooled afterglow of the early hot universe |
| Abundance of hydrogen and helium | Universe is roughly 75% hydrogen, 25% helium by mass | Matches predictions from Big Bang nucleosynthesis calculations |
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