Electricity is so familiar, and yet, so elusive.
What is electricity? There is electricity when your lover touches your hand or strokes your hair. There is electricity when two powerful people are on the point of an argument. The air might be electric before a great sporting occasion.
Or maybe electricity is the solution to the Maxwell’s equations, or the transfer of charge from one ion to another. Maybe electricity is what is stored in batteries or what comes out of the socket on the wall.
Or is electricity about lighting and thunderstorms, making the hairs on the back of your neck stand up? Or is it the aurora, lighting the arctic sky with rippling curtains of transparent colour?
Electricity is so familiar, and yet, so elusive.
Along with mass, length and time, scientists say, electric charge is a fundamental property of everything. The physicists of creation talk about the electro-weak force as one of the three vital forces of nature. Strong, electro-weak, gravity.
Neuro-biologists know that our nerves and brains run on electricity. Ions jumping the synapses, triggering more ions to jump more synapses, and in a waterfall of electric impulses, this is what memories are made of. Makes you think.
And then electronics. Humans, attempting to build an analog of the brain turned to voltages and transistors and printed circuits to make ever-more complex processing units, capable of rendering ever more detailed streetscapes, all based on the difference of a couple of volts.
Pure energy
An electron-volt is the charge on one electron raised by a single volt. It is pure energy. 1.5 x 10^18 electron volts is one calorie. A Butterfinger McFlurry has 620 Calories. A trillion electrons, each raised to a trillion volts.
Electricity flows. Down a wire, along a lightning bolt, through the interstellar dust. We can add and subtract voltages and currents. Divide volts by ohms to get amps: Coulombs per second.
By flowing, the charge creates magnetism, A single electron, flying through space, or down a wire sends out a magnetic field, radiating magnetic force. Enough magnetic force to move another moving charge. Enough to make a motor. The motor inside your CD drive is just electrons flowing in a magnetic field. And those electrons push the silver platter around
Electricity is static.
The charge that prickles the back of your neck? Static charge, forcing one hair away from the others. Electric potential twisting the hairs, forcing them apart. Strong enough to make your nerve endings tingle.
The hairs twist their roots and the nerve endings there make more electricity. Calcium ions swapping electrons, making electricity to run up and down your spine, awaking your synapses, recalling echoes of past lovers.
The boys in the physics lab, playing with Van de Graaff generators and Tesla coils, holding a million volts like it was nothing, except that it made their greasy hair struggle to rise, and stung when they pointed.
Electricity is power
Mmmm, rotating machinery! Turbogenerators, transformers, diesel-electric locomotives. Think humming machinery. Shafts weighing ten tonnes, spinning 50 times a second, perfectly balanced. Their coils passing so close to a hundred poles of the static electromagnets that it’s hard to slip a piece of paper between. Magnetic flux penetrates the flowing charge, electrons interact with magnetism. Vectors combine and give birth to raw, mechanical power.
Crossing the country at the speed of light on aluminium conductors, the power spreads like a river, keeping the wheels of industry turning, the office lights burning and powering the phones and computers that keep us in touch with friends and lovers.
Power over life and death. Electricity is a killer. An eel hides in the rocks, but when a fish swims by, the discharge is enough to stun it, and then sharp teeth spell death. The state sponsored executioner throws a switch, and flesh burns. Justice. Power.