Hubble’s law and the Big Bang theory

What the syllabus asks of you

• understand that the lines in the emission and absorption spectra from distant objects show an increase in wavelength from their known values
• use ∆λ / λ ≈ ∆f / f ≈ v / c for the redshift of electromagnetic radiation from a source moving relative to an observer
• explain why redshift leads to the idea that the Universe is expanding
• recall and use Hubble’s law v ≈ H0d and explain how this leads to the Big Bang theory (candidates will only be required to use SI units)