Saturday, July 19, 2008

Energy everywhere

I've been thinking a lot lately about energy. In a way, everyone has been thinking about it lately and it's hard not to think about it given the price and cost of the stuff our that powers almost all of our transport (that's gas if you're from the Americas and petrol if you're from Britain or it's children). By price I mean the amount of money that it costs us to buy the stuff. By cost I am hinting at the environmental damage caused as a result of oil extraction, processing, and burning.

The climate crisis (or any other name for the warming of the global climate) and the rising price and cost of oil have inspired an awful lot of talk and thought about energy. What I have been realising lately is that our current, intense concern about energy has influenced the way that we think about the world and the way that we see the world and how it works. I have heard a lot of things being talked about in terms of energy lately, many of which I had not considered in that light before.

A lot of the energy on the Earth comes from the sun and it takes many diverse forms as it transfers from plants to animals to people or from radiation to electricity to movement or from radiation to heat to climate to destruction. I could have made up a million different chains of energy movement then. All of the interesting stuff on the earth plays a part in the energy story.
Plants are a form of stored energy. They are like batteries soaking up and storing the sun's energy. Animals run on these batteries and they power all of their behaviours, just like a robot animal would require some kind of artificial battery (unless it were solar powered). In the process they become batteries themselves. We humans derive our energy from these other batteries, the plants and animals which have already concentrated the sun's energy for us.

Plants are a form of stored energy and so are animals. That should be obvious as the equation becomes a lot simpler once you look at coal and oil. Coal and oil are fossil fuels and are a concentrated form of plants and animals and of their energy. In Australia most of our electricity comes from the combustion of coal and the electricity produced supports our society and all of the behaviors that it consists of. It is too far-fetched to look at human society as another form of energy? Human society is a battery itself isn't it? Energy is often defined as the ability to do work and human society does a lot of work. For example, human society has a lot of complicated behaviour to act out, people interacting and moving all over the planet, within their own communities, cities, countries, and without. And human society is also reshaping the planet and building a lot of stuff and those things require energy.

Energy is recycled all the time on the planet in the food chain. If you leave humans out of the food chain for a second, not a lot of energy is directed into dead ends where it is not recycled. Animals exist to survive, prosper, and reproduce and if they are successful then they will multiply as their environment (including sources of energy) allows. Adding humans back into the equation, I can't see how the energy put into constructing an apartment block is recycled. It seems like a dead end for energy. But that's okay because the energy on the Earth is not finite or limited: Energy is continually being transferred from the sun to the Earth in the form of solar radiation. All the life on the planet is part of a complicated, dynamic battery in which this energy is stored. You can extend the battery metaphor beyond the life on the planet to the environment of the planet: A lot of energy is absorbed by the physical environment of the planet and the environment moves in response. For example, 71% of the Earth's surface is ocean and this huge surface area is always absorbing energy in the form of solar radiation. The sun heats the ocean and then this watery battery affects the rest of the planet, especially obviously in the form of climate.

Just as plants are as batteries on land, algae are the batteries of the sea. Algae and plants are both primary producers (or autotrophs) in that they produce organic compounds from inorganic inputs, making them the basis of the food chain. The main way that primary producers do this is, of course, photosynthesis which is how solar energy enters the food chain. Algae also produce roughly 80% of the world's atmospheric oxygen. The ocean is a bit like a huge solar panel.

I think I have said just about as much as I am apt. So much of the world around us can be thought of in terms of energy: the transfer of energy from one place to another; the conversion of energy from one form into another; and something else which I cannot remember now because I spent so much time checking the proper usage of the colons and semi-colons that I have used in this sentence. Lest we forget the semi-colon.

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