- What If We Powered the Planet With Seawater?
- What If We Built a Road Around the World?
- What If We've Already Made First Contact With Aliens?
- Discussed: What If We've Already Made First Contact with Aliens? - with Andrew Siemion
- What If We Became Cyborgs?
- What If Russia Won the Space Race?
- What If There is Life on Venus?
- Discussed: What If There Is Life on Venus? - with Sara Seager
- What If You Were Swallowed by a Crocodile?
- What If Titanosaurs Never Went Extinct?
- What If We Nuked an Asteroid?