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| Thomas Edison's first electric light bulb, 1879. |
Thomas Edison gets credit for inventing the light bulb, and it’s
entirely fair to say he deserves it. Still, just because his is the first
name in electric light doesn’t mean he has the final say in electricity.
Edison would have you think so. Like most great inventions, the
light bulb wasn’t the work of one person, but rather the result of the combined
efforts of many. Since Italian monk Giuseppe Ponzelli first theorized
that electric light was possible in 1747, many others worked on inventing the
light bulb. It took a while, though. The first commercially viable
light bulb was invented by Edison in 1878. His next effort would have to
be to invent a place to plug it in!
Well, not really. In fact, Edison figured he had that all
sorted out. Light bulbs, he posited, would draw from a direct current of
electricity. Edison worked on other electrical inventions at his Menlo
Park, New Jersey lab, and the direct current worked just fine for him. It
kept a constant supply of electricity going, so he already had a place to plug
any of his inventions in. The system of sockets and outlets we use today
would be developed soon enough.
Soon after its invention, Edison gave a very public display of his
electric lights one night, and became a sensation. This was the guy to go
to if you wanted to work in electricity, and scientists and engineers flocked
to Menlo Park to see if they could work in the shadow of Edison—now that he was
able to cast a shadow even at night.
Edison (left) and Tesla (right)
One applicant for work at Edison’s lab was a brilliant young
Serbian named Nikola Tesla. Tesla came to America with no job but with
great talent and a brilliant mind, so of course he wound up fighting with his
boss and got fired. The issue was electrical currents. Tesla didn’t
think Edison’s direct current (DC) was the best way to use electricity, favoring
what’s called alternating current (AC) instead. Edison, who didn’t care
for young upstarts telling him how to run his business, kicked Tesla to the
curb.
The difference between AC and DC is simple, but important. A
direct current is a constant, steady electrical charge moving through a wire or
some other kind of conductor. An alternating current is a series of small
electrical pulses being sent along the same conductor. The advantage, as
Tesla saw it, was that AC would let you send electricity over greater
distances, without having to maintain the constant charge of a direct current.
Basically, AC was a lot more efficient than DC, and would be much more
useful for a potential network of electrical power, which was something Edison
would need if he was going to sell many of his inventions.
Tesla didn’t have trouble finding work. He made his way to a
firm run by a rival inventor and engineer, George Westinghouse.
Westinghouse agreed with Tesla about AC, and was glad to employ him.
Within a decade, it was obvious that AC was the future, and the power
grids that we use today were under construction.
George Westinghouse, 1906
Tesla didn’t have trouble finding work. He made his way to a
firm run by a rival inventor and engineer, George Westinghouse.
Westinghouse agreed with Tesla about AC, and was glad to employ him.
Within a decade, it was obvious that AC was the future, and the power
grids that we use today were under construction.
Edison was bitter about it, and continued to promote DC,
regardless. He talked about AC as dangerous, suggesting that it was much
more likely to kill you than DC. To prove this, he gave public displays
of electrocuting animals with AC. He was losing money because of his
obstinance, and the electrocution shows he gave were also costing him in the
war for public opinion. His most famous electrocution show turned out to
be one that Edison himself didn’t even orchestrate. This was the
execution of Topsy the circus elephant. Topsy, an Asian elephant who had
already trampled three circus spectators, was declared a “bad” elephant, and
was sentenced to death. On January 4, 1903, a crowd of special guests and
members of the press were invited to kill Topsy. (The original plan was
to open the event to the public and charge admission.) Topsy was to be
hanged and poisoned, and an electrified platform was set up, just to make sure
they finished her off. The show was filmed (using the camera Edison
invented in 1895) by the Edison Manufacturing movie company. The film was sold
to kinetoscope maufacturers under the title Executing an Elephant.
It lasted a little more than a minute. The whole run of the film
showed Topsy walking onto the electrified platform and then falling over after
being electrocuted. The film was forgotten not long after.
70 years later, the film was rediscovered. It was quickly
attributed to the feud between Edison and Westinghouse, suggesting that it was
just another attempt by the inventor to defame his rival. In truth there
was no such connection, as morbid as the display was. (This film lasts a
little more than a minute and is available on YouTube, if you’re interested.
I won’t link it here.)
Topsy the elephant, right before Edison’s famous display.
Edison also tried to tie Westinghouse to pain, crime and death by
promoting the fact that the newly invented electric chair (not one of Edison’s
inventions) used AC to kill people. Edison tried to promote the use of
“to westinghouse” as a synonym of “to electrocute a criminal”. The new
term never caught on (though the electric chair did).
In the end, AC did win out, and most anything electric we use
today runs on it. Power lines carry AC electricity all over the place,
moving pulses of electricity through little gray boxes called transformers,
which keep the charge going over longer distances than DC possibly could.
DC is not without its uses, though. Subway systems run on a direct
current. That’s what the famous “third rail” of a subway system uses.
Since subways are electric, the trains run by staying in contact with the
third rail, so maintaining a constant charge in them makes more sense than the
electrical pulses that most devices use. Touching the DC rail and getting
a direct current coursing through your body is no more or less fatal than
touching a live wire carrying an AC current would be, no matter what Thomas
Edison would have you believe.
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