Task: Sentence Expansion
Input (English): This idea was later discarded : the nucleus and the ring have the same redshift , and the ring shows knotty structure which would not be visible with gravitational lensing .
Output (English): This idea was later discarded because the nucleus and the ring have the same redshift , and because more advanced telescopes revealed the knotty structure of the ring , something that would not be visible if the ring were the product of gravitational lensing .