Well, there are several theories about what is causing it.
In fact, there is little correlation of brightness to redshift at all!
Either quasars come in an extremely wide range of intrinsic luminosities, as most people believe, or their redshifts do not indicate distance.” I don't think anybody knows for sure what's causing the redshift, but you certainly can't tell the distance to a star based on the redshift. They look at stars, and say: “That is redshifted more.
This guy said: “This was an early sign that redshifts reliably indicate the distances to quasars.
However, the diagram shows a wide scatter in apparent brightness at every redshift.
Some of the material falls into the black hole, causing the emission of huge amounts of energy.” There's a big article when they discovered this: “Discovery Poses Cosmic Puzzle: Can a ‘Distant’ Quasar Lie Within a Nearby Galaxy? How on earth can we have these two objects that are different distances, at the same location?
Well, it's not a problem if you realize that you can't trust the redshift to measure the distance.
This article says: “Quasar with enormous redshift found embedded in nearby spiral galaxy with far lower redshift: unsolvable riddle for Big Bang astronomy.” I agree. The article goes on to say: “You have to be very careful about drawing conclusions because all of the Hubble constant measurements have huge systematic errors.” I like this article which came out in magazine a couple years ago: “Astronomers believed the Veil, one of the best studied supernova remnants, was 2,500 Light Years away and 18,000 years old. In fact, the Veil is only 1,500 Light Years away and 5,000 years old.” See, just four years ago, they were discovering they had radically wrong numbers.
If you believe the Big Bang theory; that is an unsolvable problem. If one constant changes, that is going to change your whole answer. How do you know any of the numbers they are telling us are right?
If you have ever been waiting at the train tracks when the train is coming, as the train comes toward you, it is squeezing the sound waves, and so the pitch goes up.
And when the train leaves you, it is stretching the sound waves, and so the pitch drops, and it goes ééééé úúúúú, as it goes by. Well, this happens whether the sound is moving past you or you are moving past the sound.
But they are so anxious to say that the universe is billions of light years across, and it probably is, and use that as evidence to say: “Therefore it's billions of years old.” And that's why this all becomes a problem for them.