Tesla’s Wireless Predictions

Wednesday, May 5th, 2010

According to a recent Telegraph headline, Nikola Tesla predicted the Blackberry a century ago — which is really missing the point, if you look back at the original Popular Mechanics piece, which itself cites the New York Times:

The attention of the world has been caught and held by the wireless telegraph, and yet this is a very primitive use of the art. So far only electric waves have been used, which have been quickly damped out in their passage through the air. It is possible, however, to transmit electric currents of enormous power for thousands of miles without diminishing their energy. This is not a theory, but a truth established by many practical experiments. It will soon be possible to transmit wireless messages all over the world so simply that any individual can carry and operate his own apparatus. The wireless transmission of power across the ocean, for instance, obviously opens up an entirely new era in mechanical developments.

It will soon be possible, for instance, for a business man in New York to dictate instructions and have them appear instantly in type in London or elsewhere. He will be able to call up from his desk and talk with any telephone subscriber in the world. It will only be necessary to carry an inexpensive instrument not bigger than a watch, which will enable its bearer to hear anywhere on sea or land for distances of thousands of miles. One may listen r transmit speech or song to the uttermost parts of the world. In the same way any kind of picture, drawing, or print can be transferred from on place to another. It will be possible to operate millions of such instruments from a single station. Thus it will be a simple matter to keep the uttermost parts of the world in instant tough with each other. The song of a great singer, the speech of a political leader, the sermon of a great divine, the lecture of a man of science may thus be delivered to an audience scattered all over the world.

More important than this, however, will be the transmission of power without wires over great distances. I have been experimenting with a model of a boat operated by electric power transmitted without wires, and the results are astounding. It is possible, I find, to control the movements of the boat absolutely from a central station without electrical connections of any kind. What has been done with a little boat on a small body of water will eventually be done by the largest liners at any distance from land. In other words, an ocean liner may be propelled across the Atlantic ocean at high speed by power directed from a wireless station on shore. We may confidently expect that within a few years many wonder now not dreamed of will be mere commonplace.

The mobile radio telephone Tesla envisions sounds like a simple, but powerful, radio transceiver — only impossibly small with the pre-transistor technology of Tesla’s day. In fact, the whole idea is not particularly practical with today’s technology either, until you introduce a cellular network, and most of what characterizes a Blackberry isn’t the radio so much as the miniature computer — a technology Tesla did not predict.

Instead, he predicted wireless power transmission. It turns out that it’s much, much easier to transmit information over the ether than significant amounts of usable energy.

Nikola Tesla Is Back in Tech Fashion

Monday, January 18th, 2010

Nikola Tesla is back in tech fashion, the Wall Street Journal reports:

When California engineers wanted to brand their new $100,000 electric sports car, one name stood out: Tesla. When circuit designers at microchip producer Nvidia Corp. in 2007 launched a new line of advanced processors, they called them Tesla. And when videogame writers at Capcom Entertainment in Silicon Valley needed a character who could understand alien spaceships for their new Dark Void saga, they found him in Nikola Tesla.

Kudos to Daniel Michaels for not mentioning the hair band as an early example of Teslamania:

An early hint was “Tesla Girls,” a 1984 single from the British technopop band Orchestral Manoeuvres in the Dark. Performance artist Laurie Anderson has said she was fascinated by Tesla. David Bowie played a fictionalized version of him in the 2006 film “The Prestige,” alongside Christian Bale and Hugh Jackman. Director Terry Gilliam described Tesla in a recent documentary film as “more of an artist than a scientist in some strange way.”

By the way, that image of Tesla is of David Bowie playing Tesla.

The beauty of Tesla is that he wrote little down, and most of what he did write down was destroyed, so you can start from some of his boasts and assume he understood just about everything well before its time:

His papers suggest he stumbled upon — but didn’t pursue — lasers and X-rays, years before their recognized discoveries. He proposed transmitting electricity through the upper atmosphere. He sketched out robots and a death ray he hoped would end all wars.
Tesla’s more outlandish pronouncements stoked that mythology. He said he could use electricity to cause earthquakes and control weather. He claimed to have detected signals from Mars while he was in Colorado.

Unlike Edison, who died in 1931 with 1,093 patents to his name, Tesla left few completed blueprints. The shortcoming undercut his legacy but added to the air of mystery surrounding him.

A History of the Death Ray

Monday, November 30th, 2009

Benjamin Wakefield provides a history of the death ray:

The concept of the modern death ray was forged in the 1920s and 1930s, when various individuals theorized the application of a particle beam or electromagnetic weapon. The American inventor Edwin R. Scott claimed to have developed a “lightning device” that could “bring down planes at a distance” (NYT, 1924). Prior to this, Harry Grindell-Matthews had tried to sell an energy weapon to the British Air Ministry. In 1923 he claimed to have invented a device that could “put magnetos out of action,” which with enough power could operate to a distance of up to four miles (Ibid.). However, despite demonstrating the weapon to journalists he was unable, or unwilling, to produce a working model for the military. Over a decade later, Antonio Longoria produced one of the more bizarre claims. Apparently he had constructed a device that could kill a mouse that had been encased in a “thick walled metal chamber” by dissolving its red blood corpuscles (Popular Science, 1940). The then president of the Inventor’s Congress, Albert Burns, said that he had witnessed dogs, cats, pigeons and rabbits being killed at a distance by this weapon (Time, 1936).

Longoria’s wanton abuse of pigeons would have angered the noted eccentric Nikola Tesla, who harbored a deep fondness for the bird. No discussion on the history of the death ray would be complete without mentioning the pioneering work of Tesla. He worked on his “teleforce” weapon from the early 1900s until his death in 1943, but because he was unable to secure any governmental funding, the project was left undeveloped. His ideas concerning the creation of the energy weapon seem to be the most viable when compared with those of Longoria, Scott, and Grindell-Matthews. His theory was that a narrow stream of particles, perhaps mercury or tungsten, could be accelerated by a high-voltage current to produce a concentrated beam of minute projectiles. Tesla believed (some would say wildly exaggerated) that this would produce enough energy to destroy “a fleet of 10,000 enemy airplanes at a distance of 250 miles” (NYT, 1934). He boasted that his weapon would have the effect of surrounding every country that used it with an impenetrable barrier, capable of destroying invading armies before they could even cross the border (Ibid.). In fact, all four of these pioneers made similar claims.

Indeed, the one thing that these men all had in common was their singular belief that their death rays could put a stop to armed conflict. Tesla optimistically referred to his weapon as a “peace-ray”—”a machine to end war” (Tesla, 1937). Similarly, Grindell-Matthews believed that “the death-ray will sweep whole armies into oblivion, whole cities into bleak, smoldering ruins, explode bombs in midair, blow up ammunition dumps from great distances [and so] end war” (Time, 1924). Fundamentally, they desired to create a weapon that was so powerful that it would act as the ultimate deterrent against war. It is no surprise, then, that when such a weapon was finally developed, public interest in the death ray dwindled. The atomic bomb took its place as the superweapon of unimaginable annihilation, surpassing the destructive capability of any of the proposed energy weapons. Although the United States National Inventors Council would continue to list the death ray as a much needed military invention until 1957 (NYT, 1957), the golden age of the concept was over by the late 1940s.

(Hat tip to Nyrath.)

The New Wizard of the West

Tuesday, July 14th, 2009

In 1899, Chauncy Montgomery M’Govern of Pearson’s magazine called Nikola Tesla the new wizard of the west and discussed his ideas for solar-thermal generation and — yes — wireless transmission:

This consists of a means of generating electricity in one spot, where it can be done with little cost, and transmitting the electricity to some other spot where it is impossible to generate electricity except at a big outlay of money.

Of course, it is now possible to transmit electrical power from one place to another by the use of electrical cables, but the cost of these transmitting cables is nearly as great as would be the cost of generating the electricity itself in the locality to which it is desired to transmit it. By the use of Tesla’s invention, the atmosphere takes the place of the electrical cables in the transmission of the power, and as the use of the atmosphere would be free, the cost of the transmission ofelectricity from one city to another would be merely nominal.

To make the atmosphere take the part of the costly cables, Tesla’s plan is to erect large power stations at every spot where a great waterfall like Niagara, for instance, makes the cost of generating electricity only trifling when the apparatus has once been constructed.

Above each of the stations Tesla wants to build a high tower, over which will be suspended a large balloon. As the electricity is generated in the station below it is conveyed by cables to the tower, and thence to the balloon, where the electricity is set free into the atmosphere. As the atmosphere at this height is much rarefied, and as Tesla has demonstrated rarefied atmosphere to be a good conductor of electricity, the electricity which is thus set free will be carried on by the atmosphere to any indefinite distance.

The second part of the Tesla plan for transmitting electrical power without wires calls for the erection of receiving stations wherever desired. These will act as sort of receivers and storage houses for the electricity set free into the atmosphcre at the generating station miles away. Over each of the receiving stations will be put up a tower and a balloon, which will be equipped with the apparatus necessary to absorb the free electricity in the atmosphere and send it to the receiving station below, from which it can be sent out on wires to light the surrounding country and drive all the machinery of that particular district.

I have more faith in his plans for wireless telegraphy. That seems like a winner.

Off Goes the Power Current Started by Thomas Edison

Friday, November 16th, 2007

I had no idea that DC power was still being delivered by the electric company in NYC. Finally, Off Goes the Power Current Started by Thomas Edison:

Today, Con Edison will end 125 years of direct current electricity service that began when Thomas Edison opened his Pearl Street power station on Sept. 4, 1882. Con Ed will now only provide alternating current, in a final, vestigial triumph by Nikola Tesla and George Westinghouse, Mr. Edison’s rivals who were the main proponents of alternating current in the AC/DC debates of the turn of the 20th century.

The last snip of Con Ed’s direct current system will take place at 10 East 40th Street, near the Mid-Manhattan Library. That building, like the thousands of other direct current users that have been transitioned over the last several years, now has a converter installed on the premises that can take alternating electricity from the Con Ed power grid and adapt it on premises. Until now, Con Edison had been converting alternating to direct current for the customers who needed it — old buildings on the Upper East Side and Upper West Side that used direct current for their elevators for example. The subway, which has its own converters, also provides direct current through its third rail, in large part because direct current electricity was the dominant system in New York City when the subway first developed out of the early trolley cars.

Despite the clear advantage of alternating current — it can be transmitted long distances far more economically than direct current — direct current has taken decades to phase out of Manhattan because the early backbone of New York’s electricity grid was built by Mr. Edison’s company, which had a running head start in the first decade before Mr. Tesla and Mr. Westinghouse demonstrated the potential of alternating current with the Niagara Falls power project. (Among the customers of Thomas Edison’s Pearl Street power plant on that first day was The New York Times, which observed that to turn on its lights in the building, “no matches were needed.”)

But direct current clearly became uneconomical, as the short distances that it could be transmitted would have required a power station every mile or less, according to Joe Cunningham, an engineering historian. Thus alternating current in New York began in the outskirts — Queens, Bronx, Upper Manhattan and the suburbs.

The direct current conversion in Lower Manhattan started in 1928, and an engineer then predicted that it would take 45 years, according to Mr. Cunningham. “An optimistic prediction since we still have it now,” he said.

As some of the comments pointed out, it isn’t quite true that AC is better for long-distance transmission:

Tesla’s AC eventually won the “war of currents” over Edison’s DC because the efficiency advantages of high-voltage transmission could only be achieved at the time using the AC transformer to step up the voltage from the generator to the grid, and then step it down again from the grid to the users.

However, technological developments in the last century have enabled high-voltage DC power transmission, which can actually achieve greater efficiency and lower equipment costs in some cases, mainly long-distance runs which don’t require intermediate taps, and undersea cables.

How mirrors can light up the world

Monday, November 27th, 2006

How mirrors can light up the world:

Two German scientists, Dr Gerhard Knies and Dr Franz Trieb, calculate that covering just 0.5% of the world’s hot deserts with a technology called concentrated solar power (CSP) would provide the world’s entire electricity needs, with the technology also providing desalinated water to desert regions as a valuable byproduct, as well as air conditioning for nearby cities.

Just “0.5% of the world’s hot deserts” sounds pretty small, but, of course, it’s not. Desert land is cheap though.

CSP is not new technology; it’s the form of solar power that’s been used in the Mojave desert for over a decade:

There are different forms of CSP but all share in common the use of mirrors to concentrate the sun’s rays on a pipe or vessel containing some sort of gas or liquid that heats up to around 400C (752F) and is used to power conventional steam turbines.

The mirrors are very large and create shaded areas underneath which can be used for horticulture irrigated by desalinated water generated by the plants. The cold water that can also be produced for air conditioning means there are three benefits. “It is this triple use of the energy which really boost the overall energy efficiency of these kinds of plants up to 80% to 90%,” says Dr Knies.

Note that these impressive efficiencies only come about if you manage to use the shade and the desalinated water for horticulture and the cold water for air conditioning — with no additional inefficiencies.

Is it competitive?

The German reports put an approximate cost on power derived from CSP. This is now around $50 per barrel of oil equivalent for the cost of building a plant. That cost is likely to fall sharply, to about $20, as the production of the mirrors reaches industrial levels. It is about half the equivalent cost of using the photovoltaic cells that people have on their roofs. So CSP is competitive with oil, currently priced around $60 a barrel.

Dr Knies says CSP is not yet competitive with natural gas for producing electricity alone. But if desalination and air conditioning are added CSP undercuts gas and that is without taking into account the cost of the carbon emissions from fossil fuels.

I must admit, this part threw me at first:

[T]he reports recommend a collaboration between countries of Europe, the Middle East and Africa to construct a high-voltage direct current (HVDC) grid for the sharing of carbon-free energy. Alternating current cables, which now form the main electricity grids in Europe, are not suitable for long distance transport of electricity because too much is lost on the way. Dr Trieb, of the German Air and Space Agency, says the advantage of DC cables is that the loss in transport is only about 3% per 1,000 kilometres, meaning losses between North Africa and Britain of about 10%.

Thomas Edison’s original power transmission system used direct current (DC), but it was quickly supplanted by Tesla’s alternating current (AC) system. I didn’t realize exactly how AC transmission was superior, and thus how an HVDC system might have its place:

Low voltage is convenient for customer loads such as lamps and motors. Early electric power distribution schemes used direct-current electrical generators located near the customer’s loads, which distributed power at the same voltage as the lamps and motors needed. As electric power became more widespread, the distances between loads and generating plant increased. Since the flow of current through the long wires resulted in a voltage drop, it became difficult to regulate the voltage at the distribution circuit extremities. Customers near the generator would have a higher voltage than those at a distance. This was undesirable because lamp life was reduced by excess voltage, and performance of motors was reduced by low voltage.

For a given quantity of power transmitted, higher voltages reduce the transmission power loss. Power in a circuit is proportional to the product of voltage and current, and the power lost as heat in the wires is proportional the square of the current. So, higher transmission voltages increase the efficiency of transmission, for a given size of conductors. Another way to reduce transmission loss is to increase the size of conductors, but since the cost of wires is approximately proportional to their weight per unit length, this strategy becomes un-economic.

The principal advantage of AC is that it allows the use of transformers to change the voltage at which power is used. With the development of efficient AC machines, such as the induction motor, AC transmission and utilization became the norm (see War of Currents). Manipulation of DC voltages is considerably more complex, and has only become economically feasible with the development of high power semiconductor devices: Thyristors, IGBTs, MOSFETS, GTOs, etc.