WiTricity

[Gurm]

http://en.wikipedia.org/wiki/Nikola_tesla

[Brian Ellis]

Look, I was studying Tesla's work long before you were born. It is over 100 years since he re-invented Hertz's work, based on Maxwell's theories. If anything useful could come of electromagnetic power transmission (and I don't mean just charging a cellphone battery at a few cm), then don't you think it would have been developed many decades ago? The fact that it hasn't is proof enough he was a charlatan and a fruitcake. I do not deny that, in his early years, he was a bloody good engineer with a touch of genius, but he went beyond the pale of scientific engineering many times for publicity. I don't deny he was a great showman, pulling stunts on a par with Barnum and Bailey, Houdini and other great showmen of his time, but his transmission of power is the same as his communications with other planets, his teletransportation and so on.

Through experimentation, he proved that transverse free space electromagnetic waves can travel over some distance. This had been predicted by James Clerk Maxwell and Michael Faraday. With his apparatus configuration, the electric and magnetic fields would radiate away from the wires as traverse waves. Hertz had positioned the oscillator about 12 meters from a zinc reflecting plate to produce standing waves. Each wave was about four meters. Using the ring detector, he recorded how the magnitude and wave's component direction vary. Hertz measured Maxwell's waves and demonstrated that the velocity of radio waves was equal to the velocity of light. The electric field intensity and polarity was also measured by Hertz.

This, from http://en.wikipedia.org/wiki/Heinrich_Rudolf_Hertz, shows that he plagiarised the work of others who had laid the foundations of his claims many years before his own claims.

Of course, it all sprang from Maxwell (when Tesla was a 8-y.o. kid):

Maxwell showed that the equations predict the existence of waves of oscillating electric and magnetic fields that travel through empty space at a speed that could be predicted from simple electrical experiments; using the data available at the time, Maxwell obtained a velocity of 310,740,000 m/s. In his 1864 paper A Dynamical Theory of the Electromagnetic Field, Maxwell wrote,

The agreement of the results seems to show that light and magnetism are affections of the same substance, and that light is an electromagnetic disturbance propagated through the field according to electromagnetic laws.

Maxwell was proved correct, and his quantitative connection between light and electromagnetism is considered one of the great triumphs of 19th century physics.

Anyone who believes the person who stated, "I have harnessed the cosmic rays and caused them to operate a motive device." at that time, must, indeed, be very naive.

[Gurm]

Look, I was studying Tesla's work long before you were born.

You've also spent a lot of time on global warming, and we all know how much we agree with you on that.

(That was a GENTLE tweak, there...)

Anyone who believes the person who stated, "I have harnessed the cosmic rays and caused them to operate a motive device." at that time, must, indeed, be very naive.

And anyone who thinks they have all the answers and know what is and isn't possible... well, that's just the sort of thinking that has stifled scientific inquiry for thousands of years.

[DGhost]

And... he could teleport shit. Seriously! Just watch "The Prestige"!

that wasn't so much teleportation... but i hate to give the plot twist away

There used to be a Tesla Museum downtown. It had some pretty neat stuff in it, unfortunately the owner was heavy into conspiracy theory and it got in the way of the business.

My own take on Tesla - while he might not have invented the theory, he was important because he would think of applications for the theory that no one else would consider. He was able to apply it in quite a few places where it wouldn't have been touched for quite a while.

unfortunately, he also had quite a few fringe ideas, concepts, etc, that made most sane people want to avoid him.

[Gurm]

Anyone who believes the person who stated, "I have harnessed the cosmic rays and caused them to operate a motive device." at that time, must, indeed, be very naive.

Actually, anyone who didn't take a look long enough to discover that Tesla had, in fact, measured cosmic background radiation... it was 1900. Why get upset that he calls it "cosmic rays"? Had he really harnessed them? Who knows... but he did manage to pull off some strange stuff!

[Brian Ellis]

but he did manage to pull off some strange stuff!

Yeah! A master at pulling stuff, especially wool over peoples' eyes!

Please explain to me why scientists have never managed to repeat, with success, many of his "findings", even with the aid of his notes. If it were just one out of many experiments or demonstrations, then it could have been put down to an empirical error or a misinterpretation, but there are literally tens of such unrepeatable bits of charlatanic showmanship that mean either a) he deliberately went out of his way to deceive others or b) he was delusional. Charitably, I hope it was the latter.

[Dr Mordrid]

Look Brian; Tesla had a list of patents in numerous countries as long as the criminal record of the Mafia's Gamboni Family, something around 275 give or take, and a lot of them are still in use today.

Whatever kind of "delusional" he was I'm sure most of us would love to catch some of it

As for Hertz and Maxwell - that could be applied to most any electrical invention since. Hell, why not drag in Volta, Ampère, Faraday, Ohm and Galvani while you're at it and call the last 2+ century's worth of progress derivative?

Jeezzz...

As for his talent for being a "showman"; today we call that "promotion" and "marketing", and without them you go nowhere when it comes to getting your inventions to market or even grants for your research.

[Gurm]

Yeah, I mean when you make some amazing discoveries about climate, you're really just ripping off the hard work of all the famous climatologists for the past 100 years, aren't you?

Piffle!

I'd like to have invented the radio, RADAR, the electric motor, A/C, and 200+ other things. That's more than you can say for just about anyone else, ever - scientist or not.

[Dr Mordrid]

BTW guys; this uses a form of magnetically coupled resonance rather than inductance.

PhysOrg....

(NOTE: I broke up the first paragraph as it ran on a bit)

the MIT team focused on one particular type: magnetically coupled resonators. The team explored a system of two electromagnetic resonators coupled mostly through their magnetic fields; they were able to identify the strongly coupled regime in this system, even when the distance between them was several times larger than the sizes of the resonant objects. This way, efficient power transfer was enabled. Magnetic coupling is particularly suitable for everyday applications because most common materials interact only very weakly with magnetic fields, so interactions with extraneous environmental objects are suppressed even further. “The fact that magnetic fields interact so weakly with biological organisms is also important for safety considerations,” Kurs, a graduate student in physics, points out.

The investigated design consists of two copper coils, each a self-resonant system. One of the coils, attached to the power source, is the sending unit. Instead of irradiating the environment with electromagnetic waves, it fills the space around it with a non-radiative magnetic field oscillating at MHz frequencies. The non-radiative field mediates the power exchange with the other coil (the receiving unit), which is specially designed to resonate with the field. The resonant nature of the process ensures the strong interaction between the sending unit and the receiving unit, while the interaction with the rest of the environment is weak.
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Moffatt, an MIT undergraduate in physics, explains: “The crucial advantage of using the non-radiative field lies in the fact that most of the power not picked up by the receiving coil remains bound to the vicinity of the sending unit, instead of being radiated into the environment and lost.” With such a design, power transfer has a limited range, and the range would be shorter for smaller-size receivers. Still, for laptop-sized coils, power levels more than sufficient to run a laptop can be transferred over room-sized distances nearly omni-directionally and efficiently, irrespective of the geometry of the surrounding space, even when environmental objects completely obstruct the line-of-sight between the two coils.
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Fisher points out: “As long as the laptop is in a room equipped with a source of such wireless power, it would charge automatically, without having to be plugged in. In fact, it would not even need a battery to operate inside of such a room.” In the long run, this could reduce our society’s dependence on batteries, which are currently heavy and expensive.

At first glance, such a power transfer is reminiscent of relatively commonplace magnetic induction, such as is used in power transformers, which contain coils that transmit power to each other over very short distances. An electric current running in a sending coil induces another current in a receiving coil. The two coils are very close, but they do not touch. However, this behavior changes dramatically when the distance between the coils is increased. As Karalis, a graduate student in electrical engineering and computer science, points out, “Here is where the magic of the resonant coupling comes about. The usual non-resonant magnetic induction would be almost 1 million times less efficient in this particular system.”

[Fat Tone]

Now you're just being ridiculous. And sure, you can counterclaim that we were being ridiculous, but that's just because you refuse to do any research into the topic. I'm not going to argue that his experiments into teleportation went anywhere (that's the stuff of movies), but power and data transmission? Absolutely.

I don't need to make an argument. Its much more fun sowing the seeds for you guys to get on with it...

[Wulfman]

what happens to the 60% of energy that doesn't land at the receiver? for the setup they showed, that's in the 50W-range...

mfg
wulfman

[Mehen]

It finds its way into the nearest human of couse!


On a sidenote, I watched The Prestige last night, it was pretty good. (on a note on an even further side I watched The Illusionist the day before, that one was REALLY good.)