What are redshift measurements?

Redshift measurements tell us how far away something is by seeing how much it has moved, like when a toy car zooms away from you and its sound gets higher or lower.

Imagine you're playing with your favorite toy train. When the train moves toward you, the sound of its whistle seems higher (like going "nee-naw" instead of "noo-naw"). But when it moves away, the sound becomes lower, like a slow, deep voice. This is called the Doppler effect, and it's what happens with light too.

When stars or galaxies move away from us in space, the light they send out gets stretched out, just like that train whistle. This makes the colors of the light look more red (even though it might not be red at all). That’s called redshift.

By measuring how much the color has shifted, scientists can tell how fast something is moving away, and from that, they can figure out how far it is. It's like knowing how fast your toy train was going by listening to its whistle!