What is the universe made of? We only know a tiny fraction — 4 percent — of the answer. From our little corner of the cosmic map, how do we know what else is out there? Luckily, we have space messengers (otherwise known as cosmic rays) that bring us data from parts of the cosmos far beyond our reach. Veronica Bindi explains how cosmic rays transmit information about our universe from the great beyond.
That number, 4 percent, never ceases to amaze me. That all of the visible, touchable, seeable matter that makes up all of everything is less than one-twentieth of the whole pie!
Luckily, not knowing is half the battle! At least when it comes to scientific curiosity.