Saw a 1930s poster warning about the dangers of electrocution and it had a red line (most probably the electricity) going from source to victim to ground. Why is that?
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here is the poster I was talking about
Electricity wants to go to ground. This means literally the ground if the earth.
In this poster someone is peeing on a suspended power line.
Urine has less resistance than air so the easiest way to electric to flow would be up the urine stream. Then into your body and out one of your legs to the ground.
This is because the body is mostly water.
Electricity flows in a loop. Normally that loop is between the two prongs in an outlet, or the two wires in a power line.
The ground can often complete that loop. Because power lines are so big and have such high voltage, they will accept the ground as one side of the loop.
Electricity follows the shortest, least resistive path to the ground. Electrical systems are bonded to ground, and then grounded, to ensure that any excessive fault current won’t destroy the systems, because that fault current is designed flow quicker to ground and minimize damage.
If you’re being electrocuted, you are unfortunately a part of that fast and easy path to ground. When you insulate yourself from the ground and work on electrical systems, you won’t be electrocuted because that grounding system is a less resistant path than you are *under normal working conditions.*
One of the core properties of electricity is something called voltage. Voltage can sort be though of like electrical pressure. If you get a bunch of electricity in one area it has high voltage(not necessarily, but it helps with the analogy). Things with high voltage dont like to be in that state in a similar way to how a a container holding high pressure will want to equalize if given the chance. Ground basically has 0 voltage. If an object with high voltage has a path towards ground it will take it assuming the resistance isn’t super high. The electrical resistance of the human body is nowhere near high enough to prevent a high voltage line from going to ground, so all that electricity will run right through your body and kill you.
Electrons have a “negative” electric charge and they want to flow to a place with an excess of positive charges, such as the ground. To do so, it will follow a path of least resistance. Air is generally an extremely good insulator and normally there need to be a build up of an enormous amount of charge before the electrons can pass through the air. This is what lightning bolts are. In comparison, the human body is an extremely good conductors. The nervous system uses electrical signals to transmit impulses from the nerve endings to the brain, so we are literally full of easy paths for the electric to follow.
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