# Tilting at windmills

1. Jul 18, 2009

### D H

Staff Emeritus
Bill Gates is now tilting at windmills -- very big windmills.

http://www.ipwatchdog.com/2009/07/13/bill-gates-seeks-patent-on-hurricane-prevention/id=4576/
Bill Gates Seeks Patent on Hurricane Prevention

Prior to stepping away from the daily grind, however, Gates managed to find time on January 3, 2008, to file some five patent applications directed to methods and systems for altering the temperature of surface water. The goal of these inventions is to prevent or at least lessen the force of hurricanes ...​

Whoa!

Just to get an order of magnitude estimate of what this entails:
Cooling just the top 10 feet of the ocean won't last long. The cooling needs to be much more pervasive -- say 100 feet. Assume a temperature difference of 50 degrees between the surface and the deep waters and assume the goal is to cool the surface by 5 degrees. So, you need to exchange 1/10 of the total volume to be cooled with deep water. Let's say you need to cool a 100 mile x 100 mile swath. (You need to hit the area around the eye, not the whole hurricane. Otherwise you would have to cool an area 500 miles across.) That's 1/10*100 feet*10,000 square miles of surface water, or about 80 cubic kilometers, that needs to be exchanged with deep water. The volume of Lake Mead: 35.2 cubic kilometers.

http://www.usatoday.com/weather/research/2009-07-15-gates-hurricanes_N.htm
The patents envision sail-maneuvered barges, with conduits 500 feet long, pumping warm water down to the depths and bringing cold water up.​

And he wants to do this with sailboats! Now that is tilting at windmills.

Caveat: The USA Today article quotes one of the co-inventors as claiming they only need to cool a 60 square mile chunk of water. (I don't buy that; 60 square miles is a circle with a diameter of 8 3/4 miles.)