How do you build an unbuildable tower?

After 144 years the tallest tower on the Sagrada Familia is finally complete, but when Gaudi first designed it, the technology to build the tower didn’t exist. We’re joined by Tristram Carfrae, structural engineer and designer at Arup who was tasked with this impossible feat over a decade ago. With the reappearance of screwworm in North America, we ask – is it ever acceptable to intentionally…