Red-shift (physics Only) (GCSE Physics)

An observed spectral line has rest 450.0 nm, observed 472.5 nm. Calculate z and state whether the galaxy is approaching or receding.

Explain why a photon emitted at ultraviolet wavelengths long ago may now be observed as visible or infrared light due to redshift.

When interpreting galaxy redshifts, why must astronomers consider peculiar velocity (local motion) as well as cosmological recession?

The dimensionless redshift z is defined as (observed wavelength - rest wavelength) divided by rest wavelength. Which algebraic expression matches that definition?

Which of these is NOT a cause of observed redshift of light from astronomical objects?

Which statement about cosmic microwave background (CMB) and redshift is correct?

A star’s spectral lines are observed at longer wavelengths than in a laboratory. This shift is called red-shift because the light is shifted towards which part of the spectrum?

Two identical spectral lines have rest wavelength 400 nm. In galaxy A the line is at 420 nm, in galaxy B at 440 nm. Which galaxy is farther away assuming Hubble’s law applies?

Which discovery about spectral line patterns in distant galaxies (same pattern but shifted) was crucial to concluding galaxies contain the same chemical elements as Earth?

If redshift measurements show all galaxies are moving away from us, does that mean we are at the centre of the Universe?

If a galaxy shows spectral lines shifted to longer wavelengths, and another galaxy shows the same lines shifted to shorter wavelengths, what do these observations indicate?