The actual observable amount doesn't remotely equal this figure, however, and even with dark matter taken into account the universe still only seems to have about a third as much stuff in it as expected. The previously mentioned CMB maps can provide a value called the critical density, which given certain observations ought to equal the total amount of matter and energy in the universe. More than that, it seemed that there was simply more stuff in the universe than had been known.

Later, evidence from things like maps of the Cosmic Microwave Background radiation showed that this was correct: in defiance of the gravitational influence of matter, the universe is expanding ever faster. Arriving in 1998, this was one of the biggest scientific announcements of the century. Studies looking at Type Ia supernovae, so-called 'standard candles' in astronomy, provided the first ever evidence that the expansion of the universe is not occurring more and more slowly, but more and more quickly as time goes on. Still, one thing was for sure: the universe sure wasn't getting bigger faster.Įxcept it is. Yet, surely, even an expanding universe must still make some sense. It was unclear whether the universe would ever fully stop expanding, or perhaps begin to contract back in on itself resulting an an eventual Big Crunch. Einstein said that the universe was static, but later accepted evidence produced by Edwin Hubble that the universe was in fact expanding, and calling the static universe hypothesis his 'greatest blunder.' Admit it, scientists: this doesn't actually do anything. What is dark energy? Dark energy is anything that makes certain enormous flaws in modern cosmology make sense.Īfter Einstein, physicists had been fairly sure how the universe was evolving: the Big Bang threw all the matter outward, as an explosion does, and now gravity is slowing that outward expansion through the natural tendency of matter to not want to move away from other matter. But dark energy is so poorly understood that the term is barely even defined. Dark matter, we can at least map, and understand it as physically distributed in the universe, much like regular matter. It's a good deal more mysterious than dark matter, a substance which is itself hidden in the shadows.

Dark energy is probably the most mysterious idea in all of physics right now.

What is the dark energy