Originally broadcast on ABC, Wednesday, January 23rd, 1957.
Preview & broadcast listing from TV Guide, dated January 19-25, 1957. (Courtesy of the blog Vintage Disneyland Tickets.)
As described @ Gizmodo -
Watching their conception of what nuclear energy was going to mean for humankind is mesmerizing: Clean, silent, infinite and without any kind of trouble if you don't make bombs with it.
A powerful genie in the bottle ready to be harnessed by the people of Earth, as Dr. Heinz Haber—a German atomic scientist himself who was in the Luftwaffe during World War II and acted as the film narrator—described.
Haber describes how, if used properly, the atom could mean salvation for humanity since "ourh coahl und oil vont last forrevarr." Ships, planes, trains, and factories all nuclear powered! In a sense, he was right. Nuclear fusion could mean the ultimate clean solution to our endless power thirst—if they ever get to make it possible. Nuclear fission, on the other hand, is quite debatable.
The more shocking statements, however, were about how they imagined radioactivity could be used for things like making bigger, safer agricultural products (just put radioactive particles in the soil!) or creating better livestock (give cows radioactive food!). I'm surprised they didn't include creating superheroes with radioactive spiders and gamma bomb explosions.