Astronomy
The Cosmic Microwave Background and the Shape of the Universe
Quick fact
The cosmic microwave background is nearly uniform, but its tiny temperature fluctuations (by only 1/100,000 of a degree) contain the imprint of the universe's geometry.
Why this is interesting
You've seen the afterglow of the Big Bang—it's the static on an old TV. But did you know that this faint glow carries a hidden map of the universe's entire shape?