16:29

All Dams Are Temporary

25:58

FREE water forever. LEGALLY!!!!

16:16

Why the US and Europe are battling for Greenland’s future | Mapped Out

2:53:12

Work Music for Deep Focus & Maximum Productivity

27:07

How to Build a Satellite

12:26

How City Water Purification Works: Drinking and Wastewater

31:33

The Oldest Unsolved Problem in Math

4:00:37

4 Hours Chopin for Studying, Concentration & Relaxation