I have just finished reading a biography of Nikola Tesla. It was not written by a technical person, but I found tesla’s speculations about resonance of the earh to be fascinating. from what I can gather, tesla conceived of radio communication in a totallt different way from his contempoaries (like Marconi and DeForest). Instead of broadcasting an RF frequency, he prposed to add electromagnetic energy to the earth’s field, at the natural resonance frequency of the earth’s magnetic field. You could then modulate this field, and transmit information anywhere on earth. Is this idea valid? has any modern researcher tried it? The guy apparently had a lot of original ideas, but failed to develop a lot of them. One of them (the Tesla turbine) appaers to have merits, but is just too difficult to develop in Y2001 (let alone with the technology of 1910).Would Tesla’s “Wardenclyff” tower have worked (as an RF communcations device?)/
Who was that maskedman?
If he returns, somebody should explain the concept of citations and sources. The forum is general QUESTIONS, not general ANSWERS.
And for today’s counterpoint, my answer is “no”.
Tesla was a genius. But his genius had limits. He was an engineer not a scientist. There’s no basis to Tesla’s belief that the Earth or its atmosphere had some resonant frequency that could be made to “vibrate” in order to transmit messages or energy.
[/ul][/list][/list][/list][/list][/list][/list][/list][sub]but maybe a teensy bit more info would be helpful![/sub]
Uncle Cecil covered this topic in Return of the Straight Dope–see the second part of What up with “broadcast power”? (Cecil did not think Tesla’s idea was practical.)
Apparently the US government was experimenting with broadcast power at least until the early 80’s:
For my senior thesis in college, I analyzed Tesla’s ideas about power transmission through the earth, taking into account the earth’s capacitance, inductive effects due to the geomagnetic field, resistive losses, etc. I did have to make several assumptions about the transmission line properties of the earth, but validated them with research and review by a geological engineer.
Bottom line: Tesla’s idea of transmitting power via the earth is not impossible, but even with a high ‘Q’ factor (resonance), the losses involved and the size of the generators and “antennas” required make it impractical compared to mainstream AC power generation and distribution.
Other interesting conclusions: If we tried to implement Tesla’s idea today, we’d render huge portions of the radio spectrum unusable due to the interference it would create. We would also have to take a completely new approach to our electrical and electronic equipment design, since there would no longer be a guaranteed “earth ground” providing a universal voltage reference point.
Although he was a brilliant inventor, Tesla was also a nutcase, especially in his later years. My favorite example - he intentionally irradiated his torso and head with high doses of X-rays because he liked the sensation of warmth it created. (You have to recieve massive doses of x-rays to actually feel them!)
Ironically, he died as a result of injuries received in an auto accident.
On power transmission:
Consider the power loss involved in sending electrical energy to your house by wire. Now consider that the losses will be much higher when transmitting through the air. Now think about one more thing: How will you measure the power used by each customer in order to bill them fairly? You have a tremendous economic loss involved in generating power and then losing damn near all of it in transmission (not to mention what that kind of wastefulness would do to the environment. Oh, and did someone say “Electrosmog?”)
On information transmission:
The Earth does have a resonance frequency - if memory serves, it is around ten hertz. Shannon’s theorem say that you can transmit information at a maximum of one half of the transmission frequency, which would be five hertz. That would be five BITS per second. You would need eight seconds to transmit a lousy forty bytes. To put that in perspective, it would take fifty five and one half days to transmit three million bytes of information - imagine downloading your favorite song as an mp3 at that rate. By the time you have the file, the group has probably broken up, reformed, had a come back tour and broken up again - and the song you downloaded is ancient history.
Neither case is really practical.
On the plus side, Tesla was a genius. He invented the alternators and motors needed to make use of A.C. electricity. A.C. makes it possible to have the power plants located far from the user. Tesla invented radio, and radio control. He had patents on things that were later used in the building of computers (AND gates.)
On the minus side, Tesla was fruity as a nutcake. He had an obsession that made him polish the silverware and compute the volume of his food before eating each meal. He could not stand to touch female flesh. He also hated pearls. He was eccentric in the extreme, and alienated most of his financial backers. Towards the end of his life, he was one of those people you see feeding pigeons in the park and nursing them in his hotel room.
No doubt about it, a great man and a genius. He was also just a little crackers.
Umm. Cites. Yeah. Well, this is all off the top of my head from the three or four biographies I have read about Tesla. Unfortunately, the books were all borrowed from diverse libraries and long since returned.
The master speaks on Tesla here.
Tesla: how can a nutcase be so smart?
The most ingenious thing he invented, IMHO, was the brushless motor.
IIRC, he stopped doing the whole X-rays as therapy thing when research showed that they were, um, unhealthy. (You think he damaged to himself, IIRC, he all but fried an assistant he had at the time.)
As for his idiosyncracies, I believe that he had an aversion to hair and, possibly, not flesh, preferred multiples of threes for everything (well, presumably everything non-mathematical), and allegedly had some of his more brilliant ideas come to him in flashes of light (pun not intended). He also supposedly got to spend a lot of time hanging out w/ Samuel Clemens, which is really cool.
Ahh, but the professional hazards of being an assistant to a Mad Scientist were much greater in that day.
“We need another Timmy!”