Why Do We Get Shocked by Electricity?
You know how, since you were a kid, your mom always told you to never touch down power lines? And you knew you’d have to listen so you wouldn’t get shocked, right. But have you ever wondered why you’d get shocked? So did we, so we dug into it.
A war of currents
In a previous blog post, we talked about The Fighting, Founding Fathers of Electricity – Nikola Tesla and Thomas Edison – and the history of their electrical battles that began in the 1880sTo summarize quickly, they competed against each other to build the electricity system that would eventually power the world. And the safety and efficiency of their opposing technologies – direct current (DC) and alternating current (AC) – were heavily contested. Here’s what went down to decide which one would carry electricity across the country.
Even though Edison got his DC electric power system on the market first, it had its limitations. The DC system generated and distributed electrical power at the same, lower voltage that customers’ lamps and motors used, which was great. But, this required the use of large, costly distribution wires, and it forced cities to build generating plants near the end-user. As a result, a city-wide DC system would have demanded a power plant every couple of blocks.
Tesla’s AC power system, however, had several technical advantages over DC. With the development of a practical transformer, Tesla could now send AC power over long distances using relatively small wires at a conveniently high voltage. And his system could also convert this higher voltage to a lower voltage that customers could actually use to power their electronic devices in their homes. This meant that AC-generating stations could be larger, more efficient, more spaced out, and implemented more easily with distribution wires that were less expensive.
Knowing he was fighting a losing battle, Edison launched a smear campaign against Tesla and his AC power, claiming it was dangerous and could kill people. He even publicly demonstrated electricity’s potential danger by giving live demonstrations of him shocking stray dogs and cats to death. Nonetheless, Tesla went on to show that AC power could be transmitted safely using the laws of physics, and his AC system now sends power all across the globe.
Here’s how we shock ourselves
Electricity requires a complete path (also known as a “closed circuit”) to continuously flow. That’s why, when you touch an exposed power line or poke your finger into a live outlet (both of which are incomplete or “open circuits”), your body completes the circuit as it makes contact with the ground. (This is also what Edison was doing when he fried the neighborhood pets with far too much electricity.)
On the flip side, think of all the little birds that stand blithely on the power lines. The reason they never get shocked or burned is because they never touch the ground and the power lines at the same time, so they never close the circuit. But whenever someone or something does accidentally close the circuit, they feel the pain, because all that energy has to go somewhere.
“When you poke your finger into a live power outlet, you get shocked because your body completes the circuit.”
In fact, that’s exactly why electric current can produce deep and severe burns both on and in your body. The power dissipates across your body’s electrical resistance, giving off great amounts of heat all the while. And when you get shocked, that means that the excessive amounts of electricity – far beyond your body’s normal amount of electrical signals – are overpowering you from within. The shock overrides your body’s normal, tiny electrical impulses, overloading the nervous system and preventing both reflexive and voluntary signals from being able to move the muscles. As a result, your muscles triggered by an external shock will involuntarily contract, and there’s nothing you can do about it. This is also the reason why people appear to grip on tighter to a power line or electric fence when they’re getting shocked by it.
In a similar fashion, your heart muscles can be thrown of their usual rhythms by an electric shock. And all it takes is seven milliamps, for three seconds, for an electric shock to kill you. The electric pulse can cause your heart to “fibrillate” (also known as beat irregularly or become arrhythmic). This can lead to death because everything else starts shutting down if the heart isn’t reset in a matter of seconds.
Why it’s okay to surround ourselves with electricity if it’s that dangerous
Every day of our lives, we interact with electricity, and we frequently get shocked by it as well. However, injury and death doesn’t happen regularly because our bodies have a built-in resistance against electricity. Plus, it’s often just in the form of harmless, low-level static electricity.
Nonetheless – depending on the amount of electric energy that you’re hit with – the exposure could result in no injury at all, devastating damage, or death. In fact, even though burns are the most common injuries from electric shocks, about 1,000 people in the United States die each year as a result of electrocution. Here’s why.
When not contained or controlled, electricity is most definitely dangerous. (Think about all those “Danger – High Voltage” signs you see plastered everywhere.) It can deliver a deadly shock, which is why you should never climb power poles or transmission towers, nor should you attempt to fix power lines knocked down by a storm. Because these closed circuits have been opened once again, putting you in danger of being shocked – possibly even to death.
But if you leave these live wires be, and call your local electricity service provider to repair them, then you can continue enjoying all the benefits and convenience of the electricity your local utility provides without needing to fear the power.