Universal Expansion

Using data gathered by the Hubble Space Telescope about 446,000 galaxies, researchers have confirmed the universe is not only expanding, but the expansion is accelerating. Those results are in line with both Einstein's theory of relativity and other studies, but the sheer size of the dataset used in this study makes it important. Scientists say dark energy is the culprit pushing everything away from everything else-- even though they're not exactly sure what dark energy is.

Two caveats should be kept in mind. First, because the nature of dark energy has not been precisely defined, scientists can't say whether the expansion will continue until all structures-- including atoms-- are ripped apart, or whether this expansion might eventually stop, or even be reversed. Second, the findings, by their nature, apply to the observable universe only. There are various cosmological theories that postulate numerous universes existing in numerous dimensions. Our universe, according to many of those theories, may be only one bubble in a froth of bubbles. Its fate may or may not say anything about the fate of the broader multiverse.