What is red-shift and how does it work?

When we see light, the colour of light that we see is determined by the wavelength of the light. Violet light has the shortest wavelength, and red light has the longest wavelength. Red shift happens when we see light that is 'redder' than when the light was emitted. This means that the wavelength of the light has increased while the light was travelling. Most physicists think that this happens because space was expanding as the light was travelling through it, and so red-shift is used as evidence that the universe is expanding.

TD
Answered by Tutor317230 D. Physics tutor

1968 Views

See similar Physics GCSE tutors

Related Physics GCSE answers

All answers ▸

In most transformers, why is the power output is less than the power input.


When going around a roundabout, why do I feel a force pulling me outwards?


X-rays and gamma rays are two types of electromagnetic radiation, state two ways in which they differ from microwave radiation


What is the difference between speed and velocity?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning