Geology, palaeontology, archaeology, atmospheric science, climate, climate change and meteorology...
How great is the damage humans are causing to the oceans by discharging so many chemicals and excreted drugs into them?
Why don't compasses point to East or West?
...and where does the sky end?
...and if so, why?
Could the testing of nuclear bombs lead to earthquakes?
Did cavemen have names? And when did people start using them?