Biology has tended to be an observational science and deriving things from first principles has not been possible in the past but I hate to predict the future on that.
Jeremiah P. OstrikerIf you take a galaxy and try to make it bigger, it becomes a cluster of galaxies, not a galaxy. If you try to make it smaller than that, it seems to blow itself apart.
Jeremiah P. OstrikerThe discrepancy between what was expected and what has been observed has grown over the years, and we're straining harder and harder to fill the gap.
Jeremiah P. Ostriker