In the 19th century, based on wavelength, the radio spectrum classified waves as long waves, short waves, and medium waves. The distance of communication was limited when radio telegraphy used long waves.
Electromagnetic waves in the wavelength band less than 200 m (1500 kHz) are named short radio waves. These can travel very long distances, are invisible, and penetrate through metals.
The application of shortwave radio was highly significant in long-distance communication.
The waves eased broadcasting and were also utilized to relay telephonic and telegraphic communications over great distances.
Shortwave frequencies are applied in amateur radio stations and portable two-way radios.
The scientist Bose, in his demonstration at Kolkata, ignited the gun powder and rang a bell using short waves, and noted the potential for wireless communication using radio waves.
Answer
Ultra short radio waves were discovered by J C. Bose, one of the prominent Indian scientists.
