Saturday, November 29, 2014
Note: This program first aired November 15, 2014.
These past weeks have been a challenge for us modern humans, living in these temperate latitudes, walking a delicate balance between the natural realities of life nearing the winter solistice at 45 degrees north, and the demands of our computers, smart phones, freezers and livelihoods here in 2014. For many of us, the November Nor’easter pushed that balance towards one end of the human spectrum, into the realm of wood stoves and water sources, candles and bees wax, propane, lamp oil and natural darkness. Knitting by candle light, reading by head lamp and early bed times accentuated these lengthening nights. We live most of our days now far on the other end of that spectrum, with 24 hours of light if we like, cooking our food with electricity, maintaining our communities through waves and wires instead of eye contact and helping hands. When the power went out, we knew what to do, even if we didn’t want to do it, or believe we had to do it. After 12 hours without electricity, you either get with the program or jump ship for a place with a generator.
This temporary lack of our simple modern convenience made me wonder about the material reality of electricity. What is it exactly? This invisible force that has the power to abruptly alter our lives so profoundly, here one moment, gone the next?
It turns out that electricity isn’t so simple. Google electricity and you find out it is made of particles, or not, no its actually waves, or not. The variety of units associated with electricity is dizzying; volts, watts, amperes, coulomb, joules. What I am interested in is what is happening, or not happening, when the power goes off. What is actually moving through the power lines, and what happens when they break? When you work at an engineering college, there are lots of people around who can answer these questions, and when I put these questions to one of my colleagues he replied unequivocally “electrons”. It’s electrons that are moving through the power lines.
Electrons are negatively charged particles, they actually have mass, though not very much of it. They are one of the three types of particles that make up atoms, the others being protons and neutrons. The protons and neutrons make up the core or nucleus of the atom, and the electrons fly around the outside and form an energetic shell around the atom’s nucleus. The outer most electrons, the ones furthest from the nucleus are called valence electrons, and when we talk about electrical current, those are the ones we are interested in. They can move relatively freely from atom to atom, and in a simple way to think about electricity, it is these valence electrons that are moving through the wires. Its important to note that powerplants don’t make electrons, the electrons are already present in the metal the wires are made of, in fact, electrons are present everywhere in all atoms! All the powerplant does is get the electrons moving, that’s why it takes energy to make electricity. When we say electricity, we really mean electrical current, which in this simple example is moving electrons through a wire. The electrical current requires a circuit, which simply means a loop. Electrons are set in motion at the powerplant, and they return to the powerplant after looping through your house and doing some work there. If there is a gap anywhere in the loop, the current stops flowing. This applies to powerlines downed by broken trees, and to the light switch in your kitchen. When the light switch is off, the circuit is purposely left open, so no current flows. When you switch the light on, you physically close the circuit, and the current flows through the lightbulb or stove top or whatever appliance or gadget you are operating.
And Google was right when it told me that electricity is a particle, no it’s a wave. It’s both. In DC, or direct current systems, it really is the electrons moving, as in our simple example. In AC or alternating current systems (which most of us have in our homes) the electrons in the wires are transmitting a wave of energy, and just like with ocean waves, the electrons don’t have much net transport as the wave passes by.
However I look at it though, I am grateful the circuit is repaired and the electrons are flowing back through my house. But I also find myself grateful for that week of darkness. Electrical power makes our lives infinitely easier than those of generations past, and enables the frenetic pace of life we tend to run at. Sitting in the dark that long week, reading by the light of the oil lamp, doing the dishes by candle light with water heated on the woodstove—these moments pulled at something old inside me. Something old and slow and precious. So don’t despair when the lights flicker and that electron flow is impeded. You remember how to do this.
The internet standard for basic physics info:
Weirdly written (perhaps translated?) but with some good basic stuff: http://www.leonics.com/support/article2_2j/articles2_2j_en.php