From Golden Age, March 24, 1926
https://jws-library.one/?file=data/1926/g_E_19260324/g_E_19260324.html#bookmark22
"MANY have wondered how accidents would be avoided during Christ’s kingdom, since we are told that nothing shall then hurt or destroy. Most accidents are due to gravitation and its effects. Falling from aeroplanes (including the negative gravity type—the heavier-than-air machines will then be obsolete), etc., may be avoided by an individual negative gravity device.
Scientists tell us that there is enough atomic energy in a finger-nail to propel a battleship. The people of the future may carry a little of this energy around with them, and if they fall down an elevator shaft they can let themselves down easy. Then they can turn on a little more and go back up. The day may not be far distant when anybody can instantly reduce his weight at will, making it equal to that of the air about him, so that he can float like a feather if he prefers. No danger of falling down stairs then.
Another source of accidents is collision. But if two autos with occupants each suddenly reduced their weight to only a few ounces above atmospheric pressure when approaching each other, they would bound apart like toy balloons and no one would be hurt."