Science progresses best when observations force us to alter our preconceptions.
Science is competitive, aggressive, demanding. It is also imaginative, inspiring, uplifting.
In a spiral galaxy, the ratio of dark-to-light matter is about a factor of ten. That’s probably a good number for the ratio of our ignorance-to-knowledge. We’re out of kindergarten, but only in about third grade.
We became astronomers thinking we were studying the universe, and now we learn that we are just studying the 5 or 10 percent that is luminous.
No observational problem will not be solved by more data.