Tesla vs Edison: just the facts

Screen Shot 2016-01-24 at 2.53.47 PMEvery year around this time I deliver a short lecture on the history of electronics. The timing of this lecture happens to roughly coincide with the anniversary of Nikola Tesla’s death, when the internet is abuzz with pop science articles, posts and tweets about the magical wizardry of Tesla. These stories are frequently accompanied by stories of Edison’s depravity as Tesla’s alleged arch-nemesis. The story alleges that Edison was obstinately fixated on a doomed technology (DC power distribution), and did everything in his power to block the arrival of the better option (AC power distribution), championed by Tesla. (Of course, nothing is so simple, and even today there is vigorous debate over the comparative advantages of DC vs AC power grids).

This tale of moral conflict among legendary inventors has been going on for decades; I recall enthusiastically reading Tesla: Man out of Time as a first year undergraduate student. More recently, the story was re-popularized by The Oatmeal in a cartoon titled “Why Nikola Tesla was the greatest geek who ever lived.”  The story is fun. I get it; I even have an Oatmeal T-shirt that says “Tesla > Edison”. Pop-science culture is virtually saturated with Tesla; he’s even featured as a super-hero in a Kickstarter-funded cartoon called “Super Science Friends.”  In spite of all this fandom, we still hear statements like this one, from one of the creators of Super Science Friends:

when you here about Tesla and Edison and all the drama, how Tesla is responsible for a lot of the things we use today but isn’t given any credit.

It’s very strange to say Tesla received no credit; he was nominated for the Nobel prize and his name was selected as the standard international unit for magnetic flux density. The story is a classic revisionist tale: the secret story of the suppressed or forgotten savior of the world. It feels like a subversive, almost conspiratorial counter-history. Only the initiated know the truth… except it’s not really accurate. Not remotely. And while Tesla is a great figure in the history of technology, the story is not very fair to Edison, who completely deserves the credit history has given him. It also is not fair to the many other contributors in the history of electricity and electronics. Tesla is simply not the “father” of electricity or of AC; he was one of many important men and women who made numerous incremental contributions. And Edison is simply not a murderous villain who nearly robbed the world of its future; you can find character flaws and moral failings in every person, including both Tesla and Edison.

Here’s a gallery of some popular memes that exhibit the degree of misconception and hero-worship that I’m addressing in this post.

[A quick note on sources: in this post I will make several references to Wikipedia entries. It is currently fashionable for skeptics to disregard Wikipedia, however the pages I’m citing appear to be well curated, have adequate references and are corroborated by other sources in my reading. If the reader is aware of any specific errors (with evidence to back you up), by all means let me know, and please go and correct the Wikipedia page directly since there’s nothing stopping you.]

Tesla’s Contributions

Let’s begin with a sober assessment of Tesla’s actual contributions. He is popularly called the “father of AC” or the “father of electricity”, but alternating current electricity was conceived long before Tesla arrived. Michael Faraday demonstrated electromagnetic induction in 1831, and Hippolyte Pixii invented the alternator for generating AC power in 1832. In the 1850s Guillaume Duchenne further developed AC technology and argued for its superiority over DC in electrotherapeutic applications (which are still used today). Then, in 1856, Tesla was born; in other words, AC technology was maturing while Tesla was a baby.

Other key developments included the evolution of AC lighting systems which began to grow in Europe around 1878, and by 1883 over 50 AC distribution sites were established for electric lighting in Austria-Hungary.  The AC power transformer appeared in 1881 and caught the attention of George Westinghouse, who began developing plans for AC power distribution in the US. In 1884 the transformer was improved by the Zipernowsky-Bláthy-Déri (ZBD) design. It’s interesting to note that the Edison Electric company acquired an exclusive patent option on the ZBD design for use in the US. This is likely because the Edison company was internally gravitating toward AC solutions in spite of Edison’s personal gut preference for DC. In 1885, William Stanley developed a superior transformer design that was licensed by Westinghouse.

At this point, in 1884, Tesla started his employment at the Edison company in New York. Tesla was aware of the progress in AC power, and tried to advocate for its use within the Edison company. Shortly thereafter, in 1886, the first AC power plant began operations in Rome, then London. AC power systems were more successful and grew more rapidly in Europe than DC systems. It was in 1886 that Tesla resigned from the Edison company and struck out on his own; his initial business venture was a lighting company (with no focus on power generation or distribution), and was a dismal and rapid failure. In 1887 he tried again with the Tesla Electric Company, which focused on electrical generators and appliances.

Since most of the elements for AC power had already been introduced, what did Tesla actually contribute? One important item: the AC induction motor, which he invented in 1887. The AC motor made it easier to employ AC electricity in industrial applications, which made it a valuable addition to the portfolio of AC products. But there are three important caveats: first, Tesla’s AC induction motor wasn’t the first of its kind; Walter Baily had demonstrated the concept in 1879, and Tesla was probably not aware that Galileo Ferraris invented a practical induction motor two years earlier, in 1885, in Italy. The second caveat is that the induction motor was not, by itself, the lynchpin that made AC triumphant over DC. The problems with DC were related to  high-voltage distribution over long distances, which didn’t match up with low-voltage requirements at customer sites (among other technical limitations that were specific to that era). Thanks to the transformer, AC was able to deliver power over long distances, down-shifting the voltage as needed for customers along the way. Third, Tesla’s motor was the type that we see in modern ceiling fans, which can only run at a fixed speed. Fixed-speed motors proved to be unusable for Westinghouse’s planned AC-powered streetcars. Because of this, Westinghouse ended up using DC power, not Tesla’s motor, for streetcar systems. In fact, DC power is still widely used for light-rail and subway transit systems today.


Tesla: father of ceiling fans.

Tesla has also been called the “father of radio,” another gross exaggeration. Tesla performed some experiments that emitted radio waves (by virtue of the fact that radio waves propagate from all wires that convey high-frequency alternating current), but he was working from an incorrect theory and his contributions were of incremental value. He invested a great deal of resources on theories that contradicted the established science of the time (Maxwell and Hertz’s theories). He rejected the canonical theory of electromagnetic waves. He developed wild ideas based on the thinnest evidence; he expected high-intensity AC current to propagate through the “aether” and illuminate the entire atmosphere; he expected to transmit currents across the Earth through the ground; he expected high-frequency signals to penetrate vast distances through the ocean. All of these expectations could be dismissed given the current scientific knowledge of that era. His misunderstandings went far beyond Edison’s stubborn support for DC. Tesla was an experimenter, a dreamer, and a storyteller, but from 1890 he drifted steadily away from concrete scientific understanding.

Told in the full context of the era, Tesla’s contributions fall short of the myth that’s been erected around him. After his early business failures, Tesla became very savvy about promoting his image and luring investors. He built himself up as a mythical figure, a wizard, and this image purportedly helped overcome his social awkwardness and eccentricity, and helped him to attract and retain investors. Unfortunately this image also resonated with pseudoscience enthusiasts and conspiracy theorists, and over the decades Tesla has been attributed a variety of allegedly repressed discoveries, such as anti-gravity, teleportation, time-travel, infinite free energy, and numerous other absurdities that elevate Tesla to a godlike persona. He was undoubtedly brilliant, and made some significant contributions to history, but he put far too much faith in his dreams, in his powers of intuition, and thereby undermined his own potential.

Tesla’s Dark Side

Like most historical figures, Tesla held views that most people today would consider downright evil. He also did some bad things. He didn’t treat everyone as well as he should have. Every person, at some point in their life, discovers how to be a terrible jerk, and Tesla was no exception. For example, Tesla was an enthusiastic proponent of eugenics. He believed in forced sterilization for criminals and the mentally ill. He believed in strict regulations on who could be permitted to marry and procreate. He also allegedly entertained antisemitic views, saying “never trust a Jew” (sadly, this was not an uncommon sentiment in his time). He made increasingly wild and unsubstantiated claims, like his proposed “death beam” (or “peace beam”) device. And even as Tesla veered further away from scientific credibility, he bitterly attacked the scientific method that began to mature in the early 20th century, saying

Today’s scientists have substituted mathematics for experiments, and they wander off through equation after equation, and eventually build a structure which has no relation to reality…. The scientists of today think deeply instead of clearly. One must be sane to think clearly, but one can think deeply and be quite insane.

Of course, the math works, and this period saw the emergence of mathematical rigor and completeness, of axiomatic theories that shored up the foundations of science for the modern era. It was mathematical completeness that ushered in the modern era of rapid, continual technological and scientific progress. And Tesla wanted nothing to do with it.

Again, I don’t say these things to malign Tesla or discredit his contributions. He was a terrific innovator, but he was one of many great minds. He was not the singular hero of his age, and I don’t think it honors his memory to elevate him to the nearly religious savior status that some people perceive.

Edison was no Villain

Thomas Edison made great discoveries and lasting contributions to both science and technology. Like anyone, he had flaws. He was greedy for recognition, money, and power. But if we demonize Edison then we also have to demonize Tesla along with a lot of other people.  In addition to his flaws, Edison held ethical standards that were progressive for his era. He was hesitant to work on military applications, insisting that he limit his investigations to purely defensive technologies. He held a strongly non-violent philosophy, saying “Until we stop harming all other living beings, we are still savages.”

At this point, many people are quick to bring up Edison’s reputation for electrocuting animals, and his supposed invention of the electric chair. According to the story, Edison was so driven to discredit Westinghouse and AC electricity, he organized a series of public demonstrations electrocuting stray dogs and cats, culminating in the public execution of Topsy the elephant. Edison’s final diabolical scheme was to invent the electric chair, for the sole purpose of smearing his AC rivals. But this story is heavily distorted and mostly fiction.

The electric chair was conceived by Alfred Southwick, who was seeking a humane method of execution. There’s no indication that he got this idea from Edison. According to Southwick’s Wikipedia entry:

In 1881, Alfred Southwick conceived the idea of electrical execution when he heard the story of an intoxicated man who touched a live electric generator. Given that the man died so quickly, Southwick concluded that electricity could be used as an alternative to hanging for executions. His first application for this phenomenon was to help invent a way to euthanize stray dogs at the Buffalo ASPCA …

After a series of botched hangings in the US there was mounting criticism of this form of capital punishment and the death penalty in general. In 1886 newly elected New York State governor David B. Hill set up a three-member death penalty commission to find a more humane form of execution. The committee included Southwick, human rights advocate and reformer Elbridge Thomas Gerry, and New York lawyer and politician Matthew Hale. They explored many forms of execution but in 1888 they recommended electrocution using a Southwick’s electric chair idea with metal conductors attached to the condemned person’s head and feet. Based on their advice the first law allowing the use of electrocution went into effect in New York State on January 1, 1889.[1] Development of Southwicks idea into a working device was turned over to the New York Medico-Legal Society.

Southwick used dogs as experimental subjects, a practice which is still commonplace today. The experiments were assisted by a physician and also the head of the local ASPCA, who was interested in an effective and humane method of euthanasia for animals.

Later, officials sought the advice of electricity experts, including Edison, and their project intersected with anti-AC activist Harold Brown, who was very motivated to prove the safety hazards associated with AC.  Brown performed some “public” experiments to demonstrate the electrical voltages needed to euthanize a horse and, by inference, a human being. These were conducted at Columbia college in a controlled setting, and were public in the sense that the press were invited, along with officials and scientists who were invited to critique the demonstrations. In the pop Tesla literature these experiments are sometimes depicted as some kind of traveling carnival show, designed to inflame the public’s irrational fears; but that doesn’t seem to be accurate. The results of these exhibitions were used by officials to set specifications on the new electric chair, which was thought at the time to be a potentially painless and instant method of execution, superior to hanging, firing squad or guillotine. It was designed to first induce unconsciousness or brain death, in order to ensure that the victim would not suffer. The design may not have succeeded in this goal, but it is nevertheless clear that the electric chair was not designed for the merely cynical purpose of smearing AC, and it was not invented by Edison.

The electric chair is often depicted as one chapter in the “War of the Currents,” a protracted competition between AC and DC utilities which was allegedly instigated by Edison via a pattern of dirty tricks and strong-arm maneuvers to promote his own business dominance at the expense of society and progress. In the pop literature, this war is typically described as a struggle between Tesla and Edison, but Tesla was mainly a spectator to the real competition between Edison and Westinghouse. The magnitude of this “war”, the degree of Edison’s self interest, and the extent to which he played dirty, are often grossly exaggerated. It’s true that Edison had bet on DC, and therefore had an interest in promoting it over AC, but his company also held options on AC patents and was developing AC solutions of its own. So it wasn’t as though his business interests hinged on DC; it’s more likely that he genuinely believed AC to be technically inferior and dangerous to the public.

The real crusader against AC was not Edison, but Harold Brown. Multiple competing utilities had created an unregulated mess of cables around New York, and a number of accidental electrocution deaths had occurred. Brown came to believe that AC electricity was inherently more dangerous than DC, and launched an aggressive public campaign for regulation against AC. In some respects, Brown was objectively correct about the mounting dangers of under-regulated power distribution amongst a cacophony of industry competitors. He can be forgiven for misunderstanding technologies that no one really understood in that era, particularly when it came to human safety.

The relationship between Edison and Brown is a little gappy, but at some point Edison took an interest in Brown’s campaign and allowed him to use some of the Edison company’s laboratory facilities. Some funding was provided by the Edison company to support Brown’s political campaign, but it’s not clear the extent to which this was driven by Edison personally, as opposed to being a product of collective decisionmaking within the Edison company. When the time came to demonstrate the first human execution by electric chair, Edison (or agents of his company) assisted in secretly obtaining Westinghouse generators for use in the demonstration. This action probably was a cynical business move meant to discredit Edison’s competition. But in the rest of the tale, Edison’s personal role seems to have been largely passive, a far cry from the cartoon-villain he is often depicted to be (for example, in the Super Science Friends cartoon).

The supposed grand climax of the War of Currents is the execution of Topsy the Elephant. It is so often written that “Edison even went so far as to electrocute an elephant” in order to steer the public away from AC. But the reality is that the War of Currents only lasted a couple of years; Brown’s campaign started in 1888 and Edison lost control of his company in the General Electric consolidation in 1889. Topsy was put down in 1903, and electrocution was chosen as a secondary option in case the first two methods, poisoning and strangulation, failed to work. It was a gruesome act, but Edison was neither involved nor present for the elephant’s electrocution. A film crew from Edison’s motion picture company did attend and record the event; they were, in effect, the first video journalists. But Edison was not involved with the company’s operations at that time.

Edison’s Contributions

Now that we’ve corrected some of the pop misconceptions about Tesla and Edison, let’s take a look at some of the contributions that show Edison’s genuine role as an innovator in both science and technology. He was an experimentalist, not a theory builder, but his observations played an important role in the development of numerous scientific subjects. The truly incredible thing is that Edison played a direct, personal role in all the inventions and discoveries listed below. He didn’t just hire smart people and profit from their talents; he was a leading participant in the research.

Edison_effect_bulb_1The light bulb: Edison’s most famous invention. Edison didn’t invent electrical lighting, but he did optimize the incandescent bulb design, selecting materials and specifications that vastly improved the bulb’s lifetime while minimizing it’s cost. But in the process he discovered something even more important: thermionic emission, known as the Edison effect:

The “Edison effect” was the name given to a phenomenon that Edison observed in 1875 and refined later, in 1883, while he was trying to improve his new incandescent lamp. The effect was that, in a vacuum, electrons flow from a heated element — like an incandescent lamp filament — to a cooler metal plate. Edison saw no special value in the effect, but he patented it anyway. Edison patented everything in sight. Today we call the effect by the more descriptive term, “thermionic emission.”

Now the Edison effect has an interesting feature. The electrons can flow only one way — from the hot element to the cool plate, but never the other way — just like the water flow through a check valve. Today we call devices that let electricity flow only one way, diodes.

The Edison effect was later studied by Fleming, De Forest, Langmuir, and others, who developed the vacuum tube diode and triode devices used in radio modulation and demodulation, computation and many other applications. In effect, Edison’s observation ushered in the electronic age.

Industrial research: It’s often overlooked, but one of Edison’s key innovations was the very concept of an industrial research laboratory. His company created the mold for GE, AT&T, Bell Labs, and all the research enterprises that followed. He discovered the means of discovery that dominated 20th century progress.

Western_Electric_double_button_carbon_microphoneThe carbon microphone: The “button” microphone was used in most telephones for nearly a century (it was independently discovered by several people in the US and Europe; Edison was granted the US patent for his co-discovery). Bell invented the telephone, but the carbon microphone made it usable. Carbon microphones are still used today in some applications, notably in backup military communication systems that are resistant to damage from power surges or electromagnetic pulses.

The phonograph: The ancestor of all automated systems for information storage and retrieval. The phonograph not only established the recording and mass media industries, it initiated the information age.

Motion pictures: In essence, Edison invented movies. His “kinetoscope” device was the basis of movie production throughout the 20th century. There had been various prior constructions, like the magic lantern, the zoetrope, the zoopraxiscope, and other exotic devices that mainly displayed simple animations. But Edison conceived the film reel and made it into a viable product. Within a few decades, the global movie industry was thriving.

X-ray fluoroscopy: Both Edison and Tesla become interested in Roentgen’s discovery of X-ray radiation. Edison’s approach was to use a fluorescent screen to directly observe the subject’s X-ray response, without using a photographic process. This procedure is still basically in use today for situations that require observing a subject in motion, or for tracking the progress of a surgical procedure. Edison’s experiments resulted in damage to his eyesight, and his assistant, Clarence Dally, ultimately died from radiation exposure. This tragic outcome is often cited as an example of Edison’s generous humanity: Edison continued to pay Dally’s salary after he became disabled, which seems like an unusual act for the caricatured 19th century greedy industrialist.

The point of this list is not to elevate Edison the way some have elevated Tesla. Edison was a flawed human being and showed an aggressive, egoistic personality in some respects. But he was not a mere thief who profited on others’ inventions. He made very significant contributions that advanced scientific knowledge and human well being.

Why does this matter?

A few weeks ago I commented on an article commemorating Tesla’s death. There was a swift, irritable reaction from the commentariat, and one commenter asked, “Why do you want to tear down Tesla? Can’t we show respect on the anniversary of his death?” My answer is that we don’t usually commemorate the deaths of scientists and inventors. We commemorate the deaths of martyrs, the anniversaries of tragic accidents or assassinations. That is how many people see Tesla: as a repressed, selfless hero, who was exploited and ultimately destroyed by the greed of evil capitalists.

It’s very significant to note that another important innovator, Richard Hamming, died on the same day 55 years after Tesla. From Hamming’s obituary in the New York Times:

Richard Wesley Hamming, who discovered mathematical formulas that allow computers to correct their own errors, making possible such innovations as modems, compact disks and satellite communications

I would argue that Hamming made more contributions that had more diverse and substantial impact than Tesla, but no one considers commemorating his death. We commemorate his achievements, not his passing. This is because we respect him as a real scientist rather than a myth. He is not a household name. There are thousands of historical scientists and innovators who made extraordinary contributions, but are not household names. So to those who enthusiastically spread the gospel of Tesla, I would ask, Why does Telsa deserve such unique significant? Why not give the same effort to all those other forgotten heroes?


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