War of Dried Fruit...oh wait

I am not the best person in the world at spelling, and rely heavily on computerized spellcheckers to ensure that my work is not riddled with errors. So when I read that on 4 January, 1903, Topsy the elephant was killed in the War of Currents, I immediately envisaged a couple of sultanas bravely facing an onslaught by a handful of raisins. In my defense, I should like to point out that the idea of AC and DC currents going to war with each other is just as nonsensical as dried fruit fighting (though in the interests of balance, fairness and embarrassing myself, I should point out that it was only after reading that Topsy was killed by Thomas Edison, via electrocution that it dawned on me that this particular war may have more to do with currents than currants...).

So let's dive right in to battle, shall we? The war of currents (sometimes known as the 'war of the currents', because Historians are crazy and wild like that), began in the late 1880s, when alternating current (AC) was invented and decided to go to war with direct current (DC).

When Thomas Edison invented the lightbulb, he used the electricity created by DC to make it work. DC works by having a constant current flowing through a wire in a similar manner to the way water flows through a pipe - how much water you have in your bucket (lightbulb) at the end depends on how fast the water flows through the pipe and how long it's been flowing for. In terms of electricity, this worked really well if you had a light switch on the wall and a lamp a few metres away that you wished to light. You could even share your electricity source with your neighbours, and they could have light too! It was all rather jolly.

There were, however, some significant problems with the system. If you wished to transfer power from its source at the power station to your home, you would need metallic cables which conducted electricity to do so. However, it took a lot of volts to light a bulb, and do the other things electricity was used for, and DC cannot be altered - if you need a high voltage at the end, you have to have a high voltage at the start, and keep that voltage high whilst the electricity travels to its end point. This proved slightly problematic, as if the current had to flow for distances greater than a mile, the wires would get so hot (due to the wasted heat energy being produced) that they would often melt and stop working. 

Edison's solution was to install lots of wires which ran over shorter distances (leading one observer to point out that this left the city of New York looking like a spider's web) but this proved dangerous, as during high winds or severe snowstorms, common in autumn and winter months, the wires would fall, electrocuting the people stood below them. In a particularly severe three day storm in March 1888, around four hundred people were killed this way. It was clear that the system couldn't continue for much longer.

Luckily, a very clever scientist named Nickola Tesla invented Alternating Current (by methods that, if I attempted to explain them, would result in my brain leaking out of my ears, so please just take my word on this one). AC, as the name suggests, alternates - sometimes it's positive, sometimes it's negative. For example, if an alternating current of 50 volts were to be measured using a oscilloscope (a fancy voltmeter), it would produce a sine wave that started at 0 volts, went up to 50, came back down to 0, went even further down to -50, came back up to 0, then further up to 50 again, and so on. 

Whilst this was very interesting to scientists, the main benefit that AC has to us all is that this enables it to be transformed - which basically means it starts off at a very high voltage at the power station, before immediately going through a transformer, which uses magic physics to lower the voltage significantly, but not the power produced from it, which means that the cables no longer heated up and melted, and power could be sent over huge distances. It was clear to everyone that this was a Jolly Good Thing Indeed, and preparations were made to switch over to AC, so that hundreds of lives could be saved, as well as many, many miles of copper cables.

Edison, however, had other ideas. He had patented the DC system, as was busy making huge amounts of money off it. He knew, though, that Tesla's invention was much better, and would soon make his old system obsolete, and therefore did everything in his power to discredit it. He claimed that it was a terribly dangerous thing - "a torrent rushing violently over a precipice" - and electrocuted animals with it to demonstrate its great danger, which is where the story of Topsy the elephant comes in.

(This is actually a really sorry tale - it made me weep, but then, anything to do with animals dying will do that... Topsy was an elephant who was kept in a zoo to perform for people, but by 1903 she had killed three men - one of whom had tried to force a lit cigarette down her throat. For this reason, she was deemed too dangerous to live, and was electrocuted using 6,600 volts of AC  by Edison, in an effort to demonstrate its dangers. He even filmed the event, and the footage is available on Wikipedia if you want to view it, but please don't - it's quite distressing...)

Tesla took the admirable stance of not saying anything derogatory about his rival and using just his own invention to prove how it was the best one to be used to provide electricity for the country. In 1897, the organizer of the Chicago World Fair asked Edison to supply the electrics for the event, and Edison agreed, requesting $1,000,000 to cover the costs of cables. Tesla approached the organizer, saying he could do it for half the price, and managed this feat. Edison was so annoyed that he banned Tesla and his sponsors from buying lightbulbs which he had patented. 

The damage to Edison's invention had been done, however. Once people saw that Tesla's alternating current was much cheaper and safer than using direct current, the switch was made, and within 10 years of the Chicago World Fair, 80% of American electricity was produced using AC. 

Which is all terribly interesting, but I'm a bit disappointed at the lack of dried fruit pummeling each other...