Sometimes, despite the hype, despite extensive funding, and despite clever and ingenious thinking, good ideas fail. Or at least don’t live up to their initial promise. There are lessons to be learnt and interesting anecdotes to be told. In this episode we look at four future-focused projects that have never really taken off: Google Glass, solar roads, space tourism and hyperloop technology.  Guests  Dr Paul Sutter – Astrophysicist, SUNY Stony Brook and the Flatiron Institute, New York  Sarah Marquart – freelance journalist, editor of From Quarks to Quasars Andrew Hawkins – Transportation editor, The Verge  Quinn Myers – Chicago-based journalist and author 'Google Glass'