In the US, we are taught at an early age that Thomas Edison was probably the greatest inventor who ever lived. There is no argument that he created some of the most spectacular technology the world has ever seen, holding over 1,000 patents.
Nikola Tesla was a Serbian-American inventor, electrical engineer, mechanical engineer, and futurist who is best known for his contributions to the design of the modern alternating current electricity supply system.
Most people have heard about the famous rivalry between Nikola Tesla and Thomas Edison. What most people are not aware of, however, is that Edison was very interested in the afterlife, and that he and Tesla both were independently working on mysterious devices to be able to communicate with departed spirits.