Science
How the world behaves, and how we found out.
Science
Why does hot water sometimes freeze faster than cold water?
Sometimes it does and sometimes it does not — and after sixty years of attempts, nobody has produced an experiment that reliably shows it or a mechanism everyone accepts.
6 min readintermediate
Science
Why is the ocean salty?
Rivers carry dissolved rock into the sea, and then only the water leaves again — evaporation takes the water and leaves the salt behind, over billions of years.
5 min read