Having read extensively about both Edison and Tesla, my personal theory is that one of the reasons Edison championed DC power over AC is that he didn't UNDERSTAND AC, especially the concept of muti-phasic AC, which is what makes the AC system really work. He was very much a DC sort of guy, who had essentially no theory behind his inventions beyond what he saw worked. That is why he had the quote about genius being 1% inspiration and 99% perspiration. One other problem he had was that even though Maxwell had published his definitive theory of electromagnetism before Edison even really started his career, Maxwell's prose was incredibly impenetrable -- especially for someone with as little formal education as Edison. Additionally, most of the real further work on the theory of electromagnetism was done in Germany (the scientific and technical hub of the world till the 1930's) and published in German, which Edison of course did not read. Tesla, on the other hand, studied electrical theory in Austria, spoke and read German, and had a mental gift for taking a bit of theory and constructing entirely complete inventions in his head. He considered the actual construction of the devices as little more than an afterthought.

Because he used to work 70 hours at a stretch -- like many computer programmers I know.

Except for just about all uses of power till home electronic equipment was invented in the 80's. In 1960 just about everything in the home was powered directly by AC (as in incandescent and florescent lights) or by an AC motor very similar to the one invented by Tesla. Only the radio needed a transformer to use AC power. Even today probably 90% of your actual power usage is of direct AC power (air conditioning and lights). So I would say that it is wrong to say Tesla was wrong.

EXCEPT for the AC electric motor and the florescent light bulb -- two of the most common uses of power even today (and certainly before about 1960). In 1960 the refrigerator, the record player, the kitchen mixer and also various household pumps were powered by what was essentially a slightly improved version of Tesla's motor. The incandescent lights were also being run off his power too. Only really the radio needed a coil to convert to DC.

What the article does not note is that Tesla didn't really claim to have invented alternating current, but he did claim (probably validly) to having invented the a working, practical AC induction motor (while a student in Europe), which made AC practical for industry. He also claimed to have invented a practical AC generator (at least he had a patent on it that he sold to Westinghouse). Additionally he did invent and patent a working system for radio and wireless signal transmission that was essentially copied by Marconi later. Add to that the Tesla coil and the working florescent light bulb, and you have a pretty impressive set of inventions. Compared to Edison (who I admire very much also) Tesla with just a couple of assistants revolutionized a great deal of the world. Edison's real claim to fame, on the other hand, was in inventing the modern invention research team system. His actual inventions were relatively few, but with teams of some dozens of inventors he spewed out patents that made him much richer and successful than Tesla (though not as rich as he wanted - he was essentially defeated in business by J.P. Morgan). Tesla unfortunately subsided into partial insanity after his attempt at power transmission in the teens, and almost every invention after that was essentially in his head.

This is not really a theory at this point. It has been demonstrated clearly in the geologic record that the earth's polarity has completely reversed at least hundreds of times (as wikipedia notes, "at an average interval of approximately 250,000 years").