Around that time, notable inventors such as Guglielmo Marconi,[1] Nikola Tesla, Harry Grindell Matthews, Edwin R. Scott, Erich Graichen[2] and others claimed to have invented it independently.
In 1923, Edwin R. Scott, an inventor from San Francisco, claimed he was the first to develop a death ray that would destroy human life and bring down planes at a distance.
All the energy of New York City (approximately two million horsepower) transformed into rays and projected twenty miles, could not kill a human being, because, according to a well known law of physics, it would disperse to such an extent as to be ineffectual.
My apparatus projects particles which may be relatively large or of microscopic dimensions, enabling us to convey to a small area at a great distance trillions of times more energy than is possible with rays of any kind.
"[12] Tesla proposed that a nation could "destroy anything approaching within 200 miles... [and] will provide a wall of power" in order to "make any country, large or small, impregnable against armies, airplanes, and other means for attack".
One German project led by Ernst Schiebold concerned a particle accelerator with a steerable bundle of beryllium rods running through the vertical axis.