Almost a hundred years ago, Einstein proposed, along with many other theories, of course, that all of space is bubbling with an invisible form of energy that creates a mutual repulsion between objects normally attracted to each other by gravity. Einstein called this force the cosmological constant. Oddly enough, this manifestation is also referred to as negative gravity. Einstein later repudiated his conjecture simply on the grounds that this "force" was too "strange". Well, He shouldn't have.
In 1997, the Hubble Space Telescope photographed, by chance, a star that exploded about 11 billion years ago, when the universe was still relatively young. Scientists theorize that then, the cosmological constant, often called "dark energy", was less powerful than gravity, the opposite of what prevails today.
Therefore, they theorize, the expansion of the universe was slowing at that time. This meant that the star was closer to earth when it exploded than it would have been if dark energy had dominated gravity then - a fact discernable in its brightness. Astronomers say it was twice as bright as it would have been under competing theories about the universe. As Einstein theorized, it appears that extremely distant supernovas do appear to brighten relative to some standard, rather than continuing to dim. Consensus has it, that if Einstein were around today, he would get another Nobel Prize for his prediction of repulsive gravity. No Doubt