Telsa was Serbian. In the the early part of the 1900's, this was an issue, as that area was the keystone in European politics and war. Because of this, He was never really accepted in the American Scientific community and held in suspicion by the government. But he made some people a lot of money and his contribution to science and society are notable. By Supreme Court Decision, Tesla invented the Radio, but they don't teach that in schools.

He also made powerful enemies, most notably Edision, for whom he worked for a short period. They differed not only in their advocacy of AC verses DC power, but in work ethic as well. Tesla had the exact opposite opinion to Edison's adage: Tesla might say that invention is 99% inspiration and 1% persperation.

He did, however, make some fantastic claims, some of them boardering on the bizzare.

What always makes me laugh, though, are the free-energy claims. Tesla's goal was the transmission of power without wire, either through the atmosphere or through the earth (telluric transmission). His experiment in charging the planet with an electric standing wave fried out the Colorado Springs electric plant and a couple of cows. There is no evidence that the experiment was effective as a viable way of transmitting energy. (Although he claimed to have sent electric power 26 miles)

Many people are worried about their cellphone causing cancer or the high transmission lines hurting those that live near them. EMF's. Can you imagine the outcry if power was delivered through the air or the ground?

A Tesla Coil is a really cool, really dangerous thing. It has nothing to do with free energy. Nothing. And if your boy is messing 'round with them, I hope he knows all about grounding and Faraday Cages. Electricity is serious biz.