Vox's Brian Resnick talks with Vera Rubin, the woman who discovered how much we don't know. The discovery of dark matter is a "blink in our knowledge," he says. Scientists are now trying to fill that gap as they look into deep space for clues.
Scientists all over the world are searching for dark matter: an invisible, untouchable substance that holds our universe together. But they haven't found it. Are they chasing a ghost?