A friend posted the very cool video of the Panama Canal in action, in time lapse:
"One week of the Panama Canal in 11 minutes. It is strangely surreal.
All 11 minutes is not required, but I recommend playing some of it in fast forward."
Another friend asked:
"Why are the oceans at different levels? I thought sea level was sea level.
Is it because of some tendency for the ocean to flow in one direction
causing the level to "pile up"?
"What would happen in they didn't have the locks? Would there be a permanent
flow of water? If so couldn't they generate a lot of power with that?"
Great question. I had to look up the answer. Many surprises.
Sea level apparently varies all over the place, depending on location as well as the tides. Salinity is a factor. Salt water is denser so areas of greater salinity are lower!
Locks would be needed even without the level difference because the canal goes up over hills! "Most of the passage through the canal is at 85 feet above sea level."
The locks are run without pumps! They use water, gravity fed from mountain lakes.
Another reference said:
"The locks are gravity fed from the Chagres and Gatun Lake. No pumps are needed. Water pours through a huge culvert in the center wall of each lock, a culvert so massive that a locomotive could pass through it. Other large culverts pass through the side walls. Water fills or empties through vents along the bottom of the locks, 26 million gallons in just eight minutes."
I also learned that the Panama Canal runs north to south, not east to west as I'd thought.
Update: Jim Knapp tells me the canal actually runs from Northwest to Southeast and is east of Miami.