.ON APRIL 2ND a device being similar to a snowfall machine on the deck of the USS Hornet, a nonexistent aircraft-carrier moored in San Francisco Gulf, began producing a haze of salted aerosol fragments. The scientific collaboration responsible for the venture, the Marine Cloud Brightening (MCB) program, led due to the College of Washington, is investigating whether such aerosols could aid to decrease weather improvement through a type of "geoengineering". What does this condition mean-- and why is it thus disputable?