How Solar X-rays Catch Invisible Particles
Tiny invisible bullets pass straight through the Sun, barely noticing its matter. These are axions — hypothetical particles so light and elusive that they are often compared to ghosts.
The Cosmos Twists Light
The oldest light in the universe has been traveling toward us for nearly 14 billion years. It was born when the cosmos first became transparent, and since then its plane of oscillation has been rotating ever so slightly. The cause is an invisible ocean permeating all of space: the dark energy field that makes the universe expand faster and faster.