From Popular Mechanics:
Scientists explain that we are missing 80 percent of the light in the universe. Just writing that sentence felt weird.Other than that...
Scientists from CU-Boulder’s Center for Astrophysics and Space Astronomy concluded after analyzing "tendrils of hydrogen" in space that something was amiss. A press release on CU-Boulder's website explains: "When hydrogen atoms are struck by highly energetic ultraviolet light, they are transformed from electrically neutral atoms to charged ions. The astronomers were surprised when they found far more hydrogen ions than could be explained with the known ultraviolet light in the universe, which comes primarily from quasars. The difference is a stunning 400 percent."
However, this cosmic mystery only pertains to nearby systems. When looking at systems billions of light years away, everything is as it theoretically should be. What exactly does this mean? Should the universe be...dimmer than it really is? “It’s as if you’re in a big, brightly lit room, but you look around and see only a few 40-watt lightbulbs,” says Juna Kollmeier, a lead author of a new study investigating the missing light.
One possible explanation is that another source is providing ionizing photons, such as the much rumored dark matter, which many scientists believe exists but have yet to prove.
As one participating scientist points out, to miss the mark by so much means what we understand about the universe is fundamentally wrong. The universe continues to be exciting, a little scary, but mostly—a mystery.
We are all idiots.