It highlights that almost all of what we know as "energy" starts as nuclear energy, and eventually becomes heat. In between, we have become expert at manipulating the various forms of energy in ways that help to improve our quality of life. The faster we move from the upper left corner to the lower right corner, or the more twists and turns we take in moving along that path, the more we waste the initial nuclear "fuel" in delivering a unit of quality of life (whether it be food, light, heat, or motion). Until Ephraim Cochrane perfects the warp coil, this is our relationship with energy. (I have a small following at present, and enough of them are Star Trek geeks that it's worth planting that reference there for them.) Our present understanding also impacts another of my favorite fictional characters: Marty McFly.
This property of near-uni-directional, near-linear, always-imperfect energy flow also means that time travel to the past is impossible.
Life always moves forward. Heat always moves from hot areas to cold ones. Fluids - air and water - always flow from areas of high pressure to areas of low pressure. We grow from children into adults. Life always moves in one direction.
For those who remember their high-school science, you have already learned the property of energy (life) that governs this...we call it entropy. We have commonly thought of entropy as a measure of chaos or disorder, but in a way, this oversimplifies it. Entropy does describe relative positions of "order" but more in a sense of probability than a sense of discipline. If we think of combinations of atoms as a deck of cards, there are thousands of possibilities for how a deck can be shuffled into an "out of order" state, but only one way that it can be arranged from the 2 of clubs to the ace of spades. If I go into any home in the country and open a used deck of cards, I am much more likely to find a shuffled deck than an ordered one. Even more precisely, when I drop a deck of cards and randomly recombine the deck, the chance that I have created a deck with all cards in order is slim to nonexistent. Whenever I move from a low probability state of energy to a highly probable one, I create entropy in the process. Moving back to the low probability state requires me to expend significant energy (much akin to the process of manually rearranging the deck).
Going back to the concept of nuclear energy and our various ways of manipulating it, our sun fuses simple hydrogen atoms into slightly less simple helium atoms, releasing significant amounts of radiation and heat energy. When we put this to direct use, for example heating or lighting our buildings, we create no additional entropy than the original process. The heat finds its way in and through our world. When we grow plants, we reverse the entropy generation process because we take the radiative form of energy and use it to synthesize organized matter (this is not a closed system, so it does not violate the second law). When we eat those plants, we break down the bonds into the constituent components, release heat energy, and build our bodies. All these forms of transfer and energy use must happen to sustain our life, therefore a balance of entropy production defines the forward path of animal and plant life here on earth.
Where we have changed things drastically is with our use of "stored" energy, namely in the decayed and compressed plant and animal life that forms our "fossil fuels". The process of growth, decay, and compression has created highly arranged substances that contain significant nuclear bonds. When we break these bonds - as we do in both fossil fuel and what we classically term nuclear energy, we release heat in amounts significant enough to drive motion, create electricity, or heat our homes. In a sense, we take hundreds of millions of years of "ordering" and release it in less than a decade. The drastic inefficiencies within this process of breaking down highly arranged materials exemplifies one of the benefits of understanding entropy. As a known, predictable quantity, it stands as a measure of how inefficiently we do the work that maintains our quality of life. Both in the amount and rate of entropy production, we have measures and predictors of how close to natural our actions can are, have been, and can be.
We see opportunities all around us for how to maintain life in "low entropy" ways. Plants take the radiation from the sun and create matter. Spiders use food at relatively low temperatures to create a material stronger than any steel cable (ounce for ounce) that we can produce with much heat and wasted energy. Our bodies create bone, and recreate it when necessary, without the aid of high pressure, temperature, or additional energy sources. As we learn more about those actions that truly sustain us, and understand the fundamental processes behind the actions, we arrive at a couple of basic conclusions:
1. The more we accomplish without any form of energy transfer, the lower the resource use and the lower the entropy generation. This means maximizing direct use of the heat, light, and radiation from the sun.
2. When we have maximized the input from these naturally occurring sources, the fewer steps we take in converting the fundamental results of the natural nuclear reactions into useful forms of energy, the more we can accomplish and the less we disrupt our surroundings. From growing food to generating electricity to developing highly efficient thermal batteries, when we maximize the amount of energy we harness and store without transfer, we create an easily sustainable future.
3. Once we have accomplished all we can through these two methods, then - and only then - we can supplement these resources to meet our needs. Until we make significant improvements in thermal and electrical battery storage, we will have trouble navigating the variability in natural energy exposure. Transitioning from our present day to a low entropy future will require a smart transition based upon low-temperature energy conversion. This will both extend the life of resources and reduce the environmental impact of the shocks associated with high-temperature, material destruction.
I will review entropy in more depth, and with some more specific applications, over the coming months. The long and the short of it is that entropy acts like nature's clock. The natural cycle of energy moving through our life occurs at a pace to which nature has adapted, and one that it expects. When we accelerate the processes of life, we introduce an element of disruption - measured by the production of entropy - that forces our surroundings to adapt to a new way of life. As we have seen over the past decades, this level of disruption negatively affects our quality of life, and we must find a way around it. We are quickly developing and deploying technologies - and more importantly learning strategies to maintain quality of life without large, destructive energy inputs - that avoid or even reverse this disruption. If we look toward entropy as our predictor of which actions will best minimize disruption and maximize productivity, we can quickly and effectively move to a largely sustainable future.
The only ones who can do this is we...because thanks to entropy, there are no Martys or Doc Browns from the future coming to tell us what to do.
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