By Richard E. Bleil, Ph.D.
As we were driving to see a national monument, the sun was on my mother’s side. There wasn’t much we could do about it, but she complained about it, saying that sun is brighter when it comes through windows. I explained that this couldn’t be the case, and suggested as proof that if it was true, I could generate enough power to run the entire world with a small light bulb. “Well, I read it,” she snapped, “so I know it’s true!” Okay, sure mom, trust what you read over your own son with a doctorate in chemistry, with a specialty in statistical thermodynamics. G’head.
There are a lot of misconceptions in science out there, and from some rather surprising sources. I had a student argue with me about hydrogen powered cars, and how they are run on free and pollution free fuel. Well, this is kind of true, but very misleading. See, the car itself is generating water, which is a good thing, but what is being left out is the source of the hydrogen.
Hydrogen is generated by the electrolysis of water. This causes the water to break down and generate hydrogen and oxygen. So no pollution right? Except, follow the source. It is possible that the source of electricity is some form of clean energy (solar, light, water, etc.), but most power plants burn coal.
Electric cars have the same issue as hydrogen powered. Until the source of electricity becomes “clean”, they are still polluting. The only difference is that, rather than polluting at the source as fossil fuel burning cars (which also pollute during the collection phase), the pollution is coming from a centralized location.
Today, there are stories about converting carbon dioxide from the air into fuel. What a marvelous bit of science fiction. Conceptually, this would be removing carbon dioxide (a greenhouse gas) from the atmosphere, which is a good thing, to produce a product (presumably like coal or oil) that can be burned for energy, which, actually, would also produce carbon dioxide, but in an ideal world, no more than the carbon dioxide removed to make it.
The problem is that ours is not an ideal world. The second law of thermodynamics tells us that it is impossible to have a one hundred percent efficient process. One of the reasons this is not one hundred percent efficient is because of the first law.
Combine these two laws, and you’ll realize a couple of problems. First, we can never get more energy out of the system than we put in. We are starting from carbon dioxide, and producing carbon dioxide. As such, the maximum amount of energy we can get out of the new fuel is equal to the amount of energy needed to produce it, and because of the second law of thermodynamics, it will always cost more energy to produce the fuel than the energy we can extract.
Again, this excess energy will come from some centralized source of energy, probably a coal-burning power plant. This power plant can burn the new fuel, but will always have to supplement it, or the energy will eventually run out. If we lived in a little community that was isolated, we could survive on the money circulating within the community itself for a while. Somebody is buying my lunches, I am paying for the food, and it’s all circulating within the community. Unfortunately, we’ll start losing money, though, as money flows out (taxes, people buying things online, etc.). If we have no money coming in to the community from outside, the money will eventually run out. Energy is the same way.
When you study science, you are given a set of tools that you can put in your toolbox. Personally, I love tools, but unfortunately rarely have the chance to use them. With the tools, you can do some amazing things, but if you don’t take them out and use them periodically, the tools will rust. The tools you learn in science class give you the basics to understand the world around us, but they will rust if you don’t use them. Think critically on occasion, so you don’t buy stock in a company that will produce free energy.
One thought on “The Importance of Basic Science 1/27/19”