sciencehabit writes: Astronomers have made the largest map yet of dark matter in the universe. This invisible stuff gives off no light, but it does exert gravity on its surroundings. It probably consists of unknown elementary particles, and it's much more prevalent than the normal matter from which stars, planets, and people are made. Link to Original Source
Today's scientific question is: What in the world is electricity?
And where does it go after it leaves the toaster?
-- Dave Barry, "What is Electricity?"