Bill breaks down the science of time travel with guests Zach Braff, retired astronaut Scott Kelly and the minds behind "Star Trek" and "Lost."
OK Go and Drew Carey help Bill explain extinction, and the panel reveals how scientists could one day bring extinct species back to life.
Bill spreads bad news about antibiotic-resistant gonorrhea and other superbugs. Comedian Ali Wong stops by the studio for a glow-in-the-dark demo.
In search of better sleep, correspondents seek out NASA scientists and a professional cuddler. Bill busts myths about naps, dreams and turkey.
From phishing to malware, Bill uncovers the scams that steal our data. Steve-O talks about the time he exposed himself … to hackers.
Bill visits a cannabis dispensary in Hollywood and takes a trip through hemp history. Kevin Smith and other panelists weigh weed's pros and cons.