Objects will be detected by radar.

Hugo Gernsback : Author
"A pulsating polarized ether wave, if directed on a metal object can be reflected in the same manner as a light ray is reflected from a bright surface… By manipulating the entire apparatus like a searchlight, waves would be sent over a large area. Sooner or later these waves would strike a space flyer. A small part of these waves would strike the metal body of the flyer, and these rays would be reflected back to the sending apparatus. Here they would fall on the Actinoscope, which records only the reflected waves, not direct ones."

Huge Gernsback. Ralph 124C 41+. New York: Experimenter Publishing. 1911.