A typical analogy explaining redshift involves a siren or a train whistle. So how do we know the same phenomenon works with light?

Question

A typical analogy explaining redshift involves a siren or a train whistle. So how do we know the same phenomenon works with light?

In: 2

Answer 1

The doppler effect… We can see it happening with objects. Light behaves as a wave and we can observe it for near and far objects to prove it works the same way as a sound wave.