Predictions about technology are notoriously tough to make. Still, the experts and visionaries often get it right — but when they don’t, they get it colossally wrong. Here are some of history’s most famously bungled insights made by tech giants and industry bigwigs, as rounded-up by Scientific American.

I predict the Internet will soon go spectacularly supernova and in 1996 catastrophically collapse.”
— Robert Metcalfe, founder of 3Com and inventor of Ethernet, writing in a 1995 InfoWorld column

I think there is a world market for maybe five computers.”
— Thomas Watson, chairman of IBM, 1943

This ‘telephone’ has too many shortcomings to be seriously considered as a means of communication.”
— Western Union internal memo, 1876

Television won’t be able to hold on to any market it captures after the first six months. People will soon get tired of staring at a plywood box every night.”
— Darryl Zanuck, 20th Century Fox, 1946

Everyone’s always asking me when Apple will come out with a cell phone. My answer is, ‘Probably never.’”
— David Pogue, The New York Times, 2006

I’d shut [Apple] down and give the money back to the shareholders.”
— Michael Dell, founder and CEO of Dell, Inc., 1997

[See more over at Scientific American]