Matt;

A brilliant school teacher in 1957 told the class something no one had ever heard. The Russian "Sputnik" was coming. It did. He also said that man is so brilliant he can change the course of a hurricane. I was born in New Orleans, finished school in Covington. Has it ever happened?

-- A.C., San Diego

Gee, AC, predicting Sputnik in '57 was a slam dunk. Predicting the control of the path of hurricanes is on some other scale entirely. Sputnik is manmade. Only Nature can make a hurricane, and when Nature gets wound up, she's a little hard to deny. No, it's never been proved scientifically that any human intervention has ever changed the course of a hurricane, but that's not to say we haven't tried. As usual, the military has been very interested in this weather-modification thing, looking at torrential rainstorms as almost as good as a boatload of tanks. Project Popeye, during the Vietnam War, was designed to seed clouds over the Ho Chi Minh trail and turn it to a bog. It did work, but a U.N resolution has subsequently made all uses of weather mod as a battle tactic illegal.

Everybody complained about the weather, but aside from invent the umbrella nobody did anything about it until the late 1940s, with Project Cirrus. Scientists at GE got the idea to seed a carefully selected hurricane well off the southern coast of Georgia with dry ice to try to reduce its size and power by reducing the cloud content. Within 24 hours of seeding, they got some cloud reduction but the hurricane veered west and crunched into land and did lots of damage. The guys at GE said the scientific equivalent of oops! and decided they'd keep the whole thing quiet so they didn't get sued. For about a decade, this put most actual hurricane experiments behind the filing cabinets. Later evaluation of the data suggested that there really was no way to tell if the hurricane had already started to bend west before the seeding, so scientifically Project Cirrus was inconclusive.

In the 1960s Project Stormfury was a plan to seed the hurricane eye wall with silver iodide to try to decrease the wall temperature and slow the wind speed and weaken the hurricane, but not change its path. In the 1980s, these experiments actually seemed to work, based on temperature and wind speed measurements, but once again we ran into the problem of scientific controls on weather experiments. Can we really be sure it was the silver iodide and not just some quirk of the cane that would have happened anyway?

Aside from one really spooky endeavor at Elgin Air Force Base, Project HAARP (weather control by tweaking the ionosphere-- though the feds say it's just a communications experiment), the biggest news lately has been Dyn-O-Mat, a superabsorbent powder that can be seeded into clouds and instantly sucks up all the water and turns it to a big gooey glob, which falls (harmlessly?) from the sky. The stuff actually works and can reduce a cloud to nothing. Again, the plan is to seed hurricane eye walls with the stuff and reduce the storm's power. Unfortunately, such vast quantities of the stuff are needed to successfully seed a hurricane, there aren't enough transport planes in the American arsenal to carry it all. Once the problems of scale are solved, we might be on the way to at least reducing a storm's power.

If you watched the TV coverage of here-comes-Katrina, you undoubtedly heard the weather wonks repeatedly say that the path of a hurricane is very hard to predict, since it depends on internal conditions in the storm, plus water temperatures, weather fronts, the jet stream, land masses, and other factors all interacting in ways that aren't always consistent or clear. So until we can predict the path more accurately, we probably won't be able to change it.