While the main characters are working in their protective suits, a power cord is clearly seen being pulled across the floor. It's obvious that the cord was not intended for the viewers to see.
Control Voice: (opening narration) In recent years, nuclear physicists have discovered a strange world of sub-atomic particles, fragments of atoms smaller than the imagination can picture, fragments of materials which do not obey the laws of gravity. Antimatter composed of inside-out material; shadow-matter that can penetrate ten miles of lead shielding. Hidden deep in the heart of strange new elements are secrets beyond human understanding-new powers, new dimensions, worlds within worlds, unknown.
Control Voice: (closing narration) As Man explores the secrets of the universe, strange and inscrutable powers await him. And whether these powers are to become forces of destruction or forces of construction will ultimately depend upon simple but profound human qualities: Inspiration. Integrity. Courage.