Big questions: dark matter

Scientists think that, in addition to the type of matter with which we are familiar, there is another kind of matter, called dark matter, that appears to be five times as plentiful as ordinary matter. Scientists are searching through their data to look for additional evidence that supports the dark matter idea. US CMS Education and Outreach Coordinator Don Lincoln tells us why this seemingly crazy idea might not be so crazy. View the video. Video: Fermilab