How do you build an unbuildable tower?

How do you build an unbuildable tower?

From BBC Inside Science by BBC Radio 4

June 11, 2026 · 26 min

About this episode

The episode discusses the completion of the Sagrada Familia tower, the ethics of species extinction, the science behind weather forecasting, and overlooked scientific discoveries.

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 drive a species to extinction? Tom is joined by Dr Gregory Kaebnick from the Hastings Center for Bioethics to dive into the science that could make it happen and the ethics stopping us. Four in five of us will check the weather daily, but do we really know what our apps are telling us? Meteorologist Simon King guides us through the complex models behind these forecasts that govern our daily decisions. Plus, science journalist Caroline Steel is in the studio bringing us the scientific discoveries the headlines missed, but that you need to know. Presenter: Tom Whipple Producer: Kate White Editor: Martin Smith Production Co-ordinator: Jana Bennett-Holesworth

People in this episode

Host: Tom Whipple

Guests: Tristram Carfrae, Dr Gregory Kaebnick, Simon King, Caroline Steel

Topics covered

  • architecture
  • ethics
  • weather forecasting
  • species extinction
  • engineering
  • scientific discoveries

Keywords

  • Sagrada Familia
  • species extinction
  • weather apps
  • engineering challenges
  • bioethics
  • scientific discoveries

Mentioned in this episode

Organizations: Arup, Hastings Center for Bioethics

Books & works: Sagrada Familia

Places: North America

More episodes of BBC Inside Science

Explore listener stats, chart rankings, contacts and more on the BBC Inside Science podcast page.