Dark energy is an even more mysterious phenomenon, a force
of some sort that beats out gravity and is causing the universe to expand at an
ever-faster pace. Some theorists have suggested that rather than invoking dark
matter, perhaps existing ideas about gravity might be wrong. Maybe gravity is
stronger on intergalactic scales than what is predicted by Newton and Einstein.
And all astronomers agree that dark matter is such an exotic idea as to border
on the crazy...