Actor, screenwriter and director Kevin Smith, who was once tapped to write his own Superman script, shares whether he thinks superhero films can sustain their outsized success, and offers his own scientific theory on one important question: How does Superman shave? Photo: AP. Click here to subscribe to our channel: / wsj Visit us on Facebook: / wsjlive Follow us on Twitter: / wsjlive Visit the Wall Street Journal: www.wsj.com Don’t miss a WSJ video, subscribe here: http://bit.ly/14Q81Xy More from the Wall Street Journal: Visit WSJ.com: http://www.wsj.com Visit the WSJ Video Center: https://wsj.com/video On Facebook: / videos On Twitter: / wsj On Snapchat: https://on.wsj.com/2ratjSM