The article below discusses Stephan's Quintet (pictured above), a galactic car accident where several galaxies have slammed into each other. The black holes in their centers destabilized and swallowed millions of solar systems. Many of them were probably inhabited by intelligent life. This is one of the most violent events ever discovered in the universe. This happened billions of years ago, billions of light years away. Or so we have been told.
This discovery has a curious side-story: one of the colliding galaxies is calculated to be eight times closer to earth than the others. This is based on its redshift, or how light wavelengths get redder with distance. The galaxy in question is more blue than the others when certain elements are measured that are used to determine its distance. These element spectroscopic lines have been used for almost a century by astronomers to determine the distance of deep space objects. But here we have an object colliding with another object that should be billions of light years apart.
This discovery throws much of our knowledge of deep space mapping into doubt. Clearly, our way of determining distance is unreliable. No one will publish this research in a professional journal due to the upheaval this has caused in modern astronomy. Instead they have attacked the author, as usual, but no one can come up with a better explanation. It is quite possible that the "red shift" method of measuring intergalactic distances has exceptions that render it useless in certain situations or with certain types of objects.
Very serious stuff.