#Spiral galaxies confound relativity (gravity) and Newton's Law of Universal Gravitation, and unseen "[[dark matter]]" has been invented to try to retrofit observations to the theories.<ref>http://arxiv.org/abs/1105.1873</ref> | #Spiral galaxies confound relativity (gravity) and Newton's Law of Universal Gravitation, and unseen "[[dark matter]]" has been invented to try to retrofit observations to the theories.<ref>http://arxiv.org/abs/1105.1873</ref> |