Today, scientists made a huge announcement: Telescopes around the world recorded a source of mysterious, ultra-high-energy cosmic rays, the highest-energy particles that hit the Earth. It all started with a text message.
Every so often, protons and even entire atomic nuclei strike the Earth with extremely high energies—much higher than what scientists can produce in their most powerful physics experiments. Since the discovery of “cosmic rays” a hundred years ago, no one knew for sure where the most energetic of these particles came…
You might have a pretty rigid understanding of the way stuff should look, at the most basic level. It should have a nucleus that is orbited by electrons. The nucleus should have protons and neutrons, inside each of which reside three quarks.
The search for dark matter—the stuff that seems to make up most of the mass in the Universe, but which is invisible to us—is loaded with new ideas, tantalizing hints, and incredibly advanced experiments. Unfortunately, none of science’s best efforts have yielded any definitive proof of dark matter’s identity.
New observations of nearby pulsars—lighthouse-like neutron stars beaming energy—seem to have deepened a mystery that’s been bugging scientists for around a decade. The Earth is being hit with too much antimatter from outer space, and no one is sure why.