What makes cosmologists and astrophysicists and astronomers so convinced the universe is expanding? How do we know redshift isn’t explained by something else? Perhaps light simply changes in a way that isn’t accounted for by the standard model since we know the standard mode isn’t the end all be all. It would be explained equally well be everything in space shrinking rather than space expanding, which has the same effects as expansion but still isn’t expansion. Have we actually observed things getting farther apart?