NIKOLA TESLA FAQ
DEBUNKING SOME
TESLA MYTHS,
fixing common widespread errors
2012 W. Beaty

1. THE "SKIN EFFECT" PROTECTS US FROM TESLA COIL ZAPS? Wrong.

Wrong wrong wrong. This misconception is actually hazardous. It's also very widespread and appears in numerous books. The true situation has serious safety implications. It's possible to cook yourself internally and not even know it. If you misunderstand these issues, you could injure yourself and others.

The skin-effect mostly applies to extremely conductive materials: to wires and metal objects. Not to salt water, not to hamburger. Human bodies aren't metal.

At the usual operating frequencies of Tesla Coils, the "skin depth" of electric currents in metals is a fraction of a millimeter. But for human flesh, skin depth is at least 50cm, HALF A METER. Or maybe more, depending on which resistivity values are used (blood vs muscle vs internal organs.) If you're zapped by a big TC, the path of current isn't on the surface. It's internal. You could accidentally cook your bone marrow. Don't forget that two common devices rely on this effect for their operation: 2GHz microwave ovens cooking the inside of meat, and in sports medicine, 27MHz diathermy muscle-warming devices used for deep-heating of muscles. These devices employ frequencies a hundred times higher than Tesla Coils, yet the "skin effect" isn't preventing the currents which produce the deep heating inside muscle tissue.

Why then no shocks? If TCs can't electrocute you, well, why not? It's simply because human nerves don't respond to AC frequencies higher than about 5KHz. (Tesla this yourself with a signal generator having HV output.) Tesla Coils can drive fairly high currents through our flesh, but they're operating at far higher than 5KHz. More like 100 to 1000KHZ, so we can't feel the electric shock; only the heating effects of the currents.

So, whenever you allow the arcs of a large TC to strike a metal wrench held in your hand, the current dives deep into your muscles. The current avoids bones and fat, follows blood vessels and muscles, and apparently heats up joint-capsules; usually your wrist, elbow, and shoulder. If your joints seem a bit painful afterwards, that's because you were being slightly cooked internally.

"I pray nightly that I never suffer an internal burn" - attributed to Tesla

(human tissue resistivity in micro-ohm-cm is 50-500 million. Blood 160ohm-cm, muscle 650ohm-cm, fat 2000ohm-cm, torso 450ohm-cm ) https://www.google.com/search?q=resistivity+body+tissues )

Yay, someone gets it right:

"People often claim that one can touch the secondary of the Tesla coil without being electrocuted because of the skin effect... However, for the frequencies normally used with Tesla coils (less than a MHz,) the skin depth typically exceeds the size of the body. Humans have a bulk resistivity of about 4-ohm-cm" - JC Sprott 2006 (p194), Physics Demonstrations: A Sourcebook for Teachers of Physics

2. TESLA WAS SCREWED OVER BY FINANCIERS AND DIED PENNILESS? NOPE.

Don't forget that Tesla lived his life in a suite of rooms in downtown NYC. That's the situation of a penniless failure? Not quite! Sure, his inventions should have made him fantastically wealthy. They didn't, but that wasn't only the fault of financiers. Besides, "not a billionaire" is very different than being "penniless." Don't forget that Tesla worked as a consulting engineer for years following the failure of Wardenclyffe (remember his bladeless turbine project?) He lost Wardenclyffe because he gambled on putting his own income into equipment and experiments, then he ignored bills for hotel rent, and then his landlord took over the Wardenclyffe property to cover those bills. Apparently Tesla held back no retirement savings, and put every cent into self-funding his personal lab. That wasn't the fault of "financiers." After the 1929 financial crash, Tesla perhaps would have died penniless, except the Tesla Foundation and Yugoslav government paid him a monthly pension of $7,200 (that's in 1940s dollars, around $100,000/yr today.) Even so, Tesla still put every cent into research, failed to pay his rent, and during his last years was still two years behind on the bills!

When Tesla famously tore up his contract with Westinghouse, instead it was renegotiated, and Tesla took a lump-sum payout of $6.5M dollars (in 2024 dollars.) By 1906 he was broke, having sunk every penny into his Wardenclyffe tower project.

Tesla's financial problems had many causes. For example, he absolutely refused to charge for (or even patent) any of his medical inventions, nor would he pursue the many idea-thieves who were reaping rewards for those inventions. His medical devices made millions for the companies who produced them without attribution to Tesla. Also, Tesla did court investors, but he then spent all his own hundreds of thousands in personally paying for research equipment and entire labs. When Westinghouse was pushed to the wall by stockholders, Tesla threw away millions (possibly billions in today's money) by tearing up his dollars-per-watt contract. In the end this didn't even help Westinghouse, since the stockholders took the company away from him anyway. Another: while building Wardenclyffe and dealing with JP Morgan, Tesla's remaining fortune was nearly wiped out in an early stock crash. Next, he couldn't find Wardenclyffe investors because of a stockmarket " wireless bubble" of numerous frauds cashing in on wireless rumors by peddling stock for fake companies. And finally, his major wealthy supporters died: Westinghouse after being forced out of his company; JJ Astor went down with the Titanic.

Perhaps part of the "penniless" myth comes not only for his refusal to pay rent, but also from Tesla's odd health beliefs and dietary experiments. At the end of his life he practiced extreme vegetarianism, and people of the time might conclude that he was too poor to afford normal food. Rumor has it that at the end he reduced this even further, and lived entirely off milk.

3. TESLA COILS ARE JUST AIR-CORE TRANSFORMERS? Not exactly.

First of all, Tesla's later work wasn't based on the transformer. Instead, his device was a single coil. A single coil connected to an AC dynamo; a cylinder or pancake coil with electrical energy being injected into one end and high voltage appearing at the other. So, no primary coil. A very strange invention! Its closest relative is one that's common in ham and cb radio: the base-loaded electrically-short car-mounted antenna: a single-wire high-Q quarter-wave resonator.

Today, Tesla's one-coil device has come to be known as the "Magnifier," as opposed to a "transformer." Tesla drove such coils directly through their ground connection. Or, sometimes he adjusted the amount of coupling by adding a conventional transformer between the dynamo and the main coil, but this wasn't essential. And finally: it's perfectly possible to build a Tesla coil with purely capacitive coupling: with an AC-driven metal plate placed near the grounded base of a single coil, and no primary coil.

As for older transformer-type Tesla coils such as "theatrical/stage" lightning-bolt machines of the Vaudeville and side-show era ...these aren't transformers; conventional transformers achieve voltage step-up based on turns-ratio of their primary and secondary coils. But with Tesla coils the turns-ratio is nearly irrelevant. Instead, the step-up effect is caused by the phenomenon known as "resonant rise." In Resonant Rise, the central role is played by the resonator's bell-like ringing or "Q-factor" of the coils. The longer time a coil can ring, the greater is the "Q" and the amount energy it can accumulate, and therefore the higher the voltage it can produce, per unit watt. With these sorts of loosely-coupled, tuned-primary tuned-secondary RF coils, the Z and the Q are the main characteristics, not the turns-ratio.

To better understand Tesla Coils, take careful note that the length of the cylindrical coil determines the operating frequency. So what? Well, if we double the length, we cut the pitch in half. What then is a Tesla coil? A Tesla coil is an organ pipe for radio waves! It's a giant whistle. And organ-pipes or flutes can be used as wave-transmitters, or to produce extremely intense standing waves where the staggaringly high value of internal AC pressure may create all sorts of novel physics effects.

ACADEMIC POLITICS: During the late 1800s, many university physics departments were having a "Mine's Bigger" competition, where Size Matters. This wasn't Cyclotron inches, instead this was in feet of spark-length with huge half-ton induction coils, with outputs approaching one megavolt. Then suddenly Nikola Tesla appeared on the scene, with his resonance-based coils (only a few kilograms of extremely thick wire, and only one or two hundred turns.) He was creating five-meter sparks, and multiple megavolts in his NYC lab. (One wonders how all the physics departments responded to this. They were all trounced by an outsider with no doctorate degree. "Got Owned by Tesla." If, forever after, the physics community made it their business to sneer at Tesla's announcements, it's no wonder why this happened.)

PATENT CASES: during the multiple court-battles over priority in radio inventions, one judge stated that "Tesla coils" could never be used as radio transmitters, since these coils required tens of thousands of turns of hair-fine wire. Such wire would just flame-out, if more than a few watts were applied. But why would he say such a thing? Who told him that Tesla Coils were just transformers? Tesla himself wasn't using secondary coils wound with hair-fine wire. Perhaps this was a dishonest effort by Marconi supporters to strengthen Marconi's theft of Tesla's inventions?
ALSO: I myself read numerous hobby-articles for building Tesla coils. They all were universal in insisting that the coil had to be 2in diameter, many feet long, and wound with tens of thousands of turns of hair-fine wire! They were treating Tesla coils as simple transformers. Not until the engineering papers of the late 1980s came out, did hobbyists discover that the ideal Tesla-coil was barrel-shaped, wound with #24ga or thicker wire, with output voltage based on high Q-factor and not on turns-ratio. (Many later coils were wound with parallel groups of wires, two or three or more, to increase the voltage by reducing "skin effect loss," as if the coil had been wound with Litz-wire.)

Also see: What is a Tesla Coil, REALLY?

4. EDISON TOOK TESLA'S IDEAS WITHOUT PAYING, SO TESLA QUIT THE COMPANY?

Just imagine if someone recommended discarding Edison's wax-cylinder phonograph and instead using flat plate disks? Would Edison welcome such changes, or despise them? Similar situation! If Edison had adopted Tesla's redesign, the Edison Corp might own those products, but they'd clearly be Tesla DC dynamos and Tesla DC motors, not Thomas Edison signature inventions like the others.

Tesla quit because of this issue, but afterwards Edison apparently didn't use any of Tesla's compact core designs. They later ended up as a main feature of the Westinghouse product line in 1889. Edison only adopted them many years later. His "Long legged" electric motors and generators silently faded away, and Tesla's short-core cylindrical motor designs (even for all DC motors!) soon took over the world.

Oddly enough, Edison's industrial DC dynamos at his European branch were being redesigned by J. Hopkinson, based on basic physics knowledge. They eventually pushed out the Long Legged format in Edison corp.

(Speculation: Hopkinson succeeded within the Edison Co., where Tesla failed, because the distant Edison branch in Europe wasn't aware that the efficient short-path designs were probably a personal affront to Edison himself, while the improved efficiency of this design were of course obvious to their European customers.)

By the way, and this is a painful reflection, it was Schmid and I who developed this type of frame and this general arrangement which is universally adopted now ...I remember years ago, some of my friends, Messrs. Crocker and Wheeler, started with those long magnets and I told them, "The sooner you throw these away and adopt (my) construction, the better it will be for you." They have got it now; it is all right. - N. Tesla, 1916

5. WORLDWIDE WIRELESS POWER CAN'T WORK, INVERSE SQUARE, AND LOSSES ARE TOO GREAT?

For Schumann Resonance to occur, the waves cannot radiate out into space, instead they must travel repeatedly around the entire Earth over and over before dying away. Going further ...the older measurements of Earth's VLF Q-factor gave a value ~10, meaning that EM waves will circle the Earth ten times before reducing to about half. Newer Q-factor measurements give values one or two orders of magnitude higher, so EM pulses will pass around the Earth hundreds of times before fading.

Yet the same pre-1950 wrong argument about "excessive losses" is still being used against Tesla today. There are quite good arguments against Tesla's scheme, but this particular debunking ...was itself debunked seventy years ago.

Does the P=1/r^2 inverse square law forbid worldwide wireless? Nope, and it's for the same reason that food in a microwave doesn't need to be placed right near the magnetron's antenna window. The microwave oven is a driven resonant cavity, and so is the Earth. Both employ standing waves, and both exhibit patterns of intense e-fields far from the actual transmitting antenna. There are nodes and antinodes, and yes, a receiver will work poorly if placed right at a node.

Think about it this way: if your power receiver is placed out in the Indian Ocean exactly 180deg away from the transmitter in the USA, wouldn't you expect to find a HUGE signal out there? Don't all the waves focus themselves at the opposite point in the atmosphere? Yes, because the system is using a driven standing wave, not a conventional radio system.

And if you traveled away from that distant maximum-spot, the power would decrease *NOT* as inverse square, but as cosine, falling to near zero at the 1/4 wavelength 1st node location, and then rising again to the peak in the next ring-shaped antinode. In fact, the same thing would happen at the transmitter! As you walked away, at first the voltage field would remain the same, no inverse-square decrease, and the fluorescent tube in your hand would stay lit. So would your Edison carbon-filament bulb. When driving an Earth-resonance, the intense KHz voltage-field would finally start dropping when you passed about 1/8 wavelength distance from the tower, or about TWENTY MILES. Yes, you could stick some light bulbs in the ground at 20 miles distant from the transmitter, and they'd light up. Cosine anti-nodes; very weird stuff. The trick is in broadcasting some radio kilowatts at 1KHz VLF wavelengths. Nobody has any clue about how Tesla could do that.

Below Tesla describes where Lord Kelvin in 1897 made the same mistake about inverse square law, but then saw the light when Tesla made clear that his system wasn't using a radio transmitter...

"In the summer of 1897 Lord Kelvin happened to pass through New York and honored me by a visit to my laboratory where I entertained him with demonstrations in support of my wireless theory. He was fairly carried away with what he saw but, nevertheless, condemned my project in emphatic terms, qualifying it as something impossible, "an illusion and a snare." I had expected his approval and was pained and surprised. But the next day he returned and gave me a better opportunity for explanation of the advances I had made and of the true principles underlying the system I had evolved. Suddenly he remarked with evident astonishment: "Then you are not making use of Hertz waves?" "Certainly not," I replied, those are radiations ... No energy could be economically transmitted to a distance by any such agency. In my system the process is one of true conduction which, theoretically, can be effected at the greatest distance without appreciable loss." I can never forget the magic change that came over the illustrious philosopher the moment he freed himself from that erroneous impression. The skeptic who would not believe was suddenly transformed into the warmest of supporters. He parted from me not only thoroughly convinced of the scientific soundness of the idea but strongly expressed his confidence in its success."
- Electrical Experimenter, Feb 1919

6. TESLA WAS CRAZY

The scientific community regarded Tesla as crazy for claiming that radio waves could bend over Earth's horizon, that the waves could travel repeatedly around the entire Earth, and that a radio broadcasting station could send signals to receivers located anywhere on the planet. All of these ideas were direct violations of known physics at the time (this was before the Heaviside Layer, even before Marconi.) Their disdainful disbelief in worldwide radio apparently prevented any investigation of Tesla's discoveries, and Earth Resonance was only rediscovered decades later after the parties in the controversy were dead.

Tesla was obviously crazy for building that giant tower at Wardenclyffe.

Hold on a sec. That giant construction was for worldwide broadcasting using a megawatt transmitter. What did BBC world service use? And Voice of America? And the USSR competitors? GIANT RADIO TOWERS AND MEGAWATT TRANSMITTERS. So perhaps Tesla only seems crazy because investors pulled out, and Long Island never became a transmitter complex for the first major worldwide radio service? Or was he only crazy because his giant radio tower was wood rather than metal, was also much shorter than many others built later, and his version had a metal sphere on top? Marconi's huge antenna complex blew down in a winter seacoast storm. He rebuilt it, then it blew down again. Built again, destroyed again. Then again. Yet Wardenclyffe tower stood unharmed for a decade, and when dynamited, remained complete as it lay on its side. (PS, Tesla's letters reveal that the Wardenclyffe tower was supposed to be three to six times taller than it was, but Tesla couldn't afford the newly-quoted construction costs.)

7. THERE'S A GLOBAL CONSPIRACY TO SUPPRESS TESLA!

So why is it that when Tesla-supporters complain about the rotten treatment dished out by the history experts and contemporary scientists, why all the accusations of "Conspiracy Theory?" Isn't this a logic fallacy, "straw man argument?"

Heh, perhaps those who complain loudest about Tesla supporters being conspiracy-theorists ...are actually GOVERNMENT AGENTS who were planted to DISCREDIT the community of Tesla fans by equating "Conspiracy Theorists" with our legitimate complaints of suppression. It's all a BIG CONSPIRACY to make it look like a conspiracy when actually it ISN'T a conspiracy!!!! (Well, that's my all-caps exclamation-points THEORY at least.) :)

8. A MAGNIFYING TRANSMITTER IS A 3-COIL DEVICE?

No, since we actually don't know what Tesla's Magnifying Transmitter really was.

The modern "Tesla coiler" community has declared that a any base-driven 3-coil device is a "Tesla Magnifier," yet Tesla himself had been using such setups at least since 1892, so to him they were not a new breakthrough deserving a new name. What was being magnified in the new "Magnifier" device? Not voltage, since all his coils did that. Perhaps peak power was "magnified" during pulse-mode operation? Or perhaps the term "Magnifying Transmitter" was simply part of Tesla's marketing hype for the Wardenclyffe project: an improved coil with heavy conductors, extensive grounding system, and a terminal covered with small adjustable hemispheres.

Or there's this pure speculation: apparently the Wardenclyffe tower contained racks for supporting some large glass devices: powerful sources to pre-ionize a discharge path above the main terminal. A Tesla Coil transmitter with a glass globe on top is fundamentally different from his other inventions. Perhaps "Magnifier" refers to a special Tesla coil including a gigantic plasma-contactor: a device for generating an invisible plasma-antenna much taller than the physical tower's height.

I saw that I would be able to transmit power provided I could construct a certain apparatus -- and I have, as I will show you later. I have constructed and patented a form of apparatus which, with a moderate elevation of a few hundred feet, can break the air stratum down. You will then see something like an aurora borealis across the sky, and the energy will go to the distant place. ...I came to the conviction that it would be ultimately possible, without any elevated antenna --- with very small elevation --- to break down the upper stratum of the air and transmit the current by conduction. -N. Tesla 1916

9. THE US GOVT BLEW UP WARDENCLYFFE TOWER TO PREVENT WW-1 GERMAN SPIES FROM CONTACTING U-BOATS? NOPE.

10. TESLA DESIGNED THE NIAGARA FALLS GENERATORS?

11. DON'T TRUST TESLA BECAUSE HE ALWAYS EXAGGERATES?

(Note that even Wardenclyffe never "failed" in this respect, instead Tesla ran out of money before the device was up and running.) Science involves "Let the experiment be made," not "bold untested ideas are as crazy as they seem; guilty until proven innocent."

A less irresponsible method of examining untested devices and determining Tesla's trustworthyness would be to examine his track record. In the past did he make any apparently crazy claims which actually proved to be crazy? In the mid-1800s everyone knew that brushless motors were impossible, and in addition, DC is the obvious choice for power systems (otherwise the great Edison wouldn't have chosen it!) Tesla's crazy AC motor ideas couldn't attract a single investor in Europe. Finally after his move to the USA, Westinghouse takes him seriously, and all of Tesla's "impossible" claims are completely vindicated. Tesla was right all along. Any physicists calling the induction motor a "perpetual motion machine" were shown to be fools. The entire expert community was wrong, while one lone voice was right.

Next, Tesla claims to send signals around the curve of the Earth and that the Earth has a fundamental resonance and overtones. He claims that a megawatt transmitter could be built to send broadcasts to the entire world. This is impossible: goes directly against 1890s physics. Tesla keeps his radio experiments secret. Marconi does not, and performs the impossible by inexplicably broadcasting around the curve of the Earth. (Later, ionospheric reflection and Heaviside's layer is discovered.) Then, oddly, the scientific community never bothers to look for Earth resonance. It was real, of course. Today it's named for its "discoverer," W.O. Schumann. Tesla's "physics-violating" crazy idea is (silently) vindicated. Tesla invents other ridiculous things: vehicles with transparent bubble cockpits, particle beam weapons, secure encoded communications, cruise missiles, VTOL aircraft. All are obviously ridiculous and were bad-mouthed in public. None attract any investors, yet each is vindicated decades later.

12. TESLA LIT UP 200 BULBS, 26 MILES FROM HIS TRANSMITTER!

This claim was in the O'Neill biography of Tesla. No other evidence.

But wait a minute. Was Tesla bragging about sending kilowatts of wireless power over that distance? Or might he have been bragging about managing to transmit actual genuine signals over that distance? In 1899 neither one had been done, so it could have been the second one.

That 26 miles ...was it roughly the distance from his lab to Pike's Peak? If so, here's a bunch of pure speculation below.

Why would *you* decide to set up a huge bank of bulbs ~30 miles away, for radio experiments? (Not Tesla. You.) It's obvious: it's for instantly testing distant receiver equipment. Yes, I could pay a telegraph company to string 40KM of wires and poles out to a distant receiver shack. Or I could have my assistants riding horseback, back and forth daily, delivering timed lab-notebook entries of the receiver readings. Or they could be signalling me at the main lab with large sun-mirrors. Or ...or ...I could set up a huge cluster of BATTERY OPERATED light bulbs, then view them through a telescope. High watts, large battery bank needed, to be seen 30mi away in daylight.

Rats, that doesn't work! The problem is that anything more distant than ~15KM is hidden by the curve of the Earth. I'd need a tower a quarter-mile tall, with bulbs on top. Unless! Ho ho ho, unless I find a laboratory location with a nearby mountain, and I place my receiver-shack at a few hundred feet elevation, up in the foothills with dirt roads. Yessss, a distant lab way out in the boonies, with no industrial spies watching my every move, even no educated eyewitnesses. I'd pulse my transmitter, and watch the distant bank of bulbs through my binocs, and instantly I know the power level needed to trigger the receiver. Sweep my beam across the receiver, plot its sectional profile!

Mister Cisco! Pack all the trunks, we're taking the next train to Pike's Peak!

Hmm, oddly enough, three years before his 1899 lab, Tesla apparently was in Colorado Springs, even climbed up Pikes Peak ( jpg) and performed resonance experiments with portable radio equipment, sending the music for 'Ben Bolt' through the bedrock. Wow.

13. TESLA DISCOVERED X-RAYS!

14. TESLA COULDN'T HAVE DISCOVERED X-RAYS: VACUUM PUMPS WEREN'T GOOD ENOUGH

15. THE SECRET OF TESLA'S DEATH-RAY IS LOST

16. TESLA'S "STATIC ELIMINATOR" IS A PAIR OF ADJUSTABLE PANCAKE COILS

By the term "static eliminator," Tesla was describing an invention somewhat akin to Edwin Armstrong's FM radio scheme: a system which was immune to thunderstorm static; such thunderstorm signals being AM-only. In other words, FM radio is a "static eliminator" invention.

We have little direct evidence of how Tesla's version worked, but it was probably a variation on Tesla's patent on spread-spectrum "frequency hopping." Most probably it was a spinoff from what he called "Method of Individuation," of secure and non-interceptable comms produced by his "Sectional Circuits" and employing the concept of the "Wave-Complex." Wave-Complex was a transmitted signal employing a beat-wave or "line-splitting" frequency effect produced by an excited multi-resonator device. In modern terms this was FHSS, a Spread-Spectrum comm system based upon near-random Frequency-hopping. But Tesla's frequency-hopping was analog, not digital; and his random hopping effect was produced naturally via several interacting tuned circuits Tesla named "sectional circuits." Visualize a radio receiiver with several tuning knobs for each channel, rather than just one knob, and where thunderstorms cannot duplicate the odd, multi-peak spectrum to which only the special receivers will respond. "Static free" reception like FM! But based on a spread-spectrum technique.

"Static Eliminator" was his cleaned-up prototype; a demonstration model to show off Tesla's unjammable "Method of Individuation" modulation scheme. See N. Tesla 1/1919 "The Effect of Statics on Wireless Transmission" also Horizontal-polarized antennas: Marconi/Weagant's 'static eliminator'

It is what I call a 'static preventer.' A great trouble, when I came to Colorado, was that I could not 'operate' at all. You know that the static interference is today the great bane of the wireless transmission. The reason for that is defective construction of the plants, but with this invention I am enabled to even make these defective plants operate satisfactorily.

The principle involves the employment of a plurality of tuned circuits in series as shown [in diagram of "sectional circuits."] However, any interaction of the circuits, arising from mutual induction, produces results which are exceedingly complex. The emitted note will not be pure because of the beats produced. - N. Tesla 1916

17. THE TESLA-PROMOTERS ARE LYING. EVERYONE IS FAMILIAR WITH TESLA'S ACCOMPLISHMENTS!

18. TESLA IS SERBIAN! TESLA IS CROATIAN!

19. TESLA CAUSED THE TUNGUSKA BLAST

1. A 10 megaton blast, or about 40 billion megajoules, would require broadcasting radio energy at a level of 10 megawatts for 130 years (that is, if the process was 100% efficient, longer if not.) In other words, the power-grid connected to Wardenclyffe can't produce megaton-scale explosions.

2. Coupling a VLF transmitter's output to the Earth resonance wavelengths requires a miles-long antenna similar to the US Navy submarine-comms low-freq transmitter projects (project Seafarer/Sanguine, Mary Creek, etc.) Actually this is a problem for many of Tesla's claims: he used no miles-long antennas, yet his devices supposedly could transmit enormous wattage at VLF/ELF wavelengths. Modern physics declares this impossible.

3. A meteor or comet is a sudden brief event, while if Tesla did it, there'd probably be a slow buildup. We'd expect to see various odd atmospheric phenomena occurring for many minutes or even hours before any "explosion." There might even be several explosions in series, multiple beat-waves separated by a constant delay. If it was a single blast with no precursors, then it wasn't a 'Tesla event.'

4. Legend has it that Tesla intended to produce artificial aurora at North Pole, but he overshot the mark. So, if Tunguska isn't on the great-circle including Wardenclyffe tower and the North Pole, then the claim fails right there. A random comet/meteor strike will probably be in a completely unrelated location. Go get a world globe and look.

So, Tesla could not have caused the blast unless...

1. He discovered an enormous energy source in the Earth's Schumann cavity, and his transmitter only acted as a catalyst or trigger and not the main energy supply. This is the "TWT Theory" of Tesla's World System (analogous to a microwave Travelling-wave tube, an RF amplifier having an external DC power supply.)
2. Unless Tesla had some secret method of "getting out," of transmitting significant VLF wattage without an appropriate long-wire antenna,
3. unless minutes/hours of strange phenomena were observed in Russia prior to the and following the blast,
4. unless Tunguska is on the straight line between Wardenclyffe and the North Pole.

So "Tunguska blasts" may possibly be man-made. Still there's #2, and it would require an antenna very much larger than Wardenclyffe's tower to be able to transmit anything more than a tiny-wattage signal at VLF wavelengths. Hmmm. Corum and Corum point out that a resonant cavity not only violates inverse-square law, but the built-up resonance violates antenna-impedance rules, and because of strong local standing-waves, an electrically-short "waveguide probe" can emit far more wattage than a quarter-wave ground-plane antenna tower. Even more: they find that a resonant "microwave probe" antenna can launch low-loss Zenneck surface-waves, while a quarter-wave tower only emits very lossy Norton surface-waves, the two very different solutions of Maxwellian wave-equations. Hrm. Maybe Tesla empirically discovered some very genuine EM physics which the scientific community declared "impossible," and weren't understood theoretically until the 1980-2010 era! Hmmm!

" "It is perfectly practicable to transmit electrical energy without wires and produce destructive effects at a distance. I have already constructed a wireless transmitter which makes this possible, and have described it in my technical publications, among which I may refer to my patent 1,119,732 recently granted. With transmitters of this kind we are enabled to project electrical energy in any amount to any distance and apply it for innumerable purposes, both in peace and war. ...the power transmitted need not be necessarily destructive, for, if existence is made to depend upon it, its withdrawal or supply will bring about the same results as those now accomplished by force of arms.
"But when unavoidable, the same agent may be used to destroy property and life. The art is already so far developed that great destructive effects can be produced at any point on the globe, determined beforehand and with great accuracy. In view of this I have not thought it hazardous to predict a few years ago that the wars of the future will not be waged with explosives but with electrical means." " - N. Tesla 1915

20. TESLA COILS ARE AMAZING LIGHTNING MACHINES

21. TESLA COILS ARE ALWAYS HORIZONTAL AND UNGROUNDED. ANY VERTICAL COIL IS AN OUDIN COIL.

Back before WWII, this strange notion was heavily propagated by hobbyist radio magazines. Vertical coils are always called "Oudin Coils?" But Tesla himself used both configurations. (coughWardenclyffe&Colorado) Perhaps the idea was motivated by confusion over Marconi's stolen "Spark Transmitter" system ...which of course was a Tesla Coil.

The "Tesla coil" was actually invented by three separate people: Thompson, Oudin, and Tesla. Their discoveries were independent. Thompson and Tesla both investigated capacitor-discharge, and found that the damped ringing impulses could be stepped up to high voltage. But when Thompson and Tesla faced off in the press, Thompson politely backed down and gave the credit to Tesla. At about the same time Oudin in France was doing the same thing. Oudin's was a single coil with a clamp-on tap (although a similar setup appears in Tesla's 1892 presentation to the Royal Society.) More important, Oudin's was exclusively a medical invention for "electrical therapy," while Tesla's was intended to be a radio transmitter. So, an Oudin coil *IS* a Tesla coil, which *IS* a Thompson coil.

22. TESLA DISCOVERED RADIO!

On numerous occasions Tesla insisted that his invention was not radio, and that Marconi's radio was feeble and usless. According to Tesla the so-called "Hertzian waves" might work for line-of-sight signalling but not for powering an advanced worldwide civilization.

Tesla's "non-radio wireless" sprang out of his early attempts to light up the sky itself, eliminating night and any need for lightbulbs. He did this by producing some sort of guided-lightning discharge up to what's now called the Ionosphere, and then using a huge transmitter to run the Ionosphere like a giant fluroescent glow-lamp. He also found that this glow-discharge in low pressure was the same as a conductor; a power line across the sky which wrapped around the entire Earth. This was the origin of his "Wireless Power" system. He even patented it, and when the USPTO rejected his initial application, he had the head of that office come and see his protoptype: two HV coils connected by many yards of hollow glass pipe, with the pipe pumped down to near vacuum. It was like a neon-sign being used as a wire; a high-volt, low current transmission line, the same as conventional power lines, but without using metal cables. He demonstrated that he could send kilowatts and drive large electrical loads at the step-down coil at the far end of the pipe. It's now one of Tesla's patents.

But what about Marconi? Marconi history suggests a direct theft of Tesla's invention, but only for powering a radio transmitter and not a whole-sky lightning discharge. Marconi's early publicity campaign zeroed on his "whip crack" system, his brief impulses with damped sine waves. Supposedly this pulse signal would reach much farther than competitors. (The competitor was Tesla, with his high-power "CW" continuous sine waves.) Marconi had been working with the head of the British Post Office, William Preece. Marconi found that his system couldn't be received further than a few tens of miles, and Preece insisted that Marconi deal with Tesla, to license Tesla's system with its much longer range. Marconi didn't. At this time Preece suddenly dropped out, Marconi went silent about the glories of "whip-crack," and Marconi's transmitters suddenly started broacasting over hundred of miles. Almost certainly this is the point when Marconi gave up his broadband single-resonator transmitters and started employing Tesla's narrow-tuned CW, the "two resonators each at transmitter and receiver, with all four tuned to the same frequency." This radio system was Tesla's patented invention (also known as a "Tesla Oscillator.") And after the big legal battle, the "four resonators" description became the legal definition of Radio. In other words, Radio is actually a pair of distant Tesla coils connected to long-wire antennas. [SEE MORE]

So, Tesla invented radio because Tesla's sytem won the race, and Marconi took it entire, without paying a cent to Tesla. But Tesla didn't invent radio, because Tesla had only little interest in sending feeble useless Morse Code signals to distant ships or between the continents. Tesla instead wanted to power those ships with his transmitter ...as well as powering every train and car across the planet, as well lighting the sky and eliminating night.

23. TESLA WAS THE REAL INVENTOR OF...

1. Coaxial Cable
2. Radar
3. Neon signs
4. Fluorescent lighting
5. Earthquake machine
6. Car speedometer
7. Automobile spark-ignition

This was a very useful invention for anyone who wanted to connect the top of a Tesla coil to a long cable, and either hang the cable at the ceiling for powering wireless home appliances, or to send the cable off to directly power distant devices. Without the chain of pipes to cover the conductor, huge lightning bolts would spring from all along its length. Obviously the pipes could not be grounded, since that would just short out the whole system with power-arcs to the cable. But why the segments? That's for two reasons: with a thin cable, the cable acts as a resistor, and the a high voltage may develop lengthwise. The pipe must maintain very small voltage inside, and breaking it up into segments lets this happen. Second, at high enough AC frequency, the cable starts to behave as an antenna, or at least as a waveguide. The voltage at one spot won't be the same as the voltage farther along. So, the outer pipe needs to be split into segments which are far shorter than one-fourth wavelength at the operating frequency.

24. EDISON BURNED DOWN TESLA'S LAB IN COLORADO

25. OK, THEN EDISON BURNED DOWN TESLA'S LAB IN NYC