Daniel always assumed the ocean was just born salty.

It wasn't. It became salty. Gradually. Over billions of years.

The answer involves rain, rocks, rivers, and a system so well balanced that ocean salinity has been roughly stable for hundreds of millions of years.

What you will find in this episode:

• Why rainwater is slightly acidic and what that does to rocks over time
• How rivers carry dissolved minerals to the sea -- and why rivers taste fresh but oceans don't
• Why the ocean doesn't just keep getting saltier forever
• What hydrothermal vents on the seafloor have to do with salt
• The 150-meter fact that still stops people mid-sentence
• Why the Dead Sea is ten times saltier than the ocean
• The closing line that reframes every swim you have ever taken

Short,  ...