Doppler Fishes
Sarah LeVine (UCB)

Oil on canvas, 24x30 inches
When a train approaches, the pitch of its whistle seems high and then when it passes the pitch drops. This is because the whistle’s sound waves are getting squished together as the train comes towards you, and stretched out as it moves away. The same thing happens with light. As a light source in space such as the Andromeda Galaxy moves towards us, its light waves get compressed and the patterns in its spectral lines all get shifted towards the blue end of the spectrum. The opposite thing happens to nearly all other celestial objects: they are red-shifted because they are moving away. Due to red-shift we can tell the universe is expanding. This school of yellow fish illustrate Doppler shift as they swim towards us from the right and away from us on the left.