For years I have been enamored with the basic principle of conservation of energy. I know that’s a bit weird, but since when is that a surprise?
Why am I enamored with this principle? At heart (or at mind, maybe?) I really am much more of a deductive rather than an inductive reasoner. When presented with a problem, my mind naturally seeks to simplify it, to identify non-pertinent information so that it can be removed from the analysis, to classify the problem so that the number of potential solutions or analysis techniques can be reduced. This is very objective-oriented thinking, and it isn’t always helpful. That’s one reason why I like working with people who reason very inductively. It just makes sense, and it helps me challenge myself to be more open and less critical.
Often, however, deductive reasoning is very helpful, and I love collecting tools for my mental toolbox that help me out with this. I have found that one of the most powerful and useful of those tools is the principle of conservation of energy. In short, it says that in a closed system, energy can neither be created nor destroyed, but can only change form. This principle is exceedingly useful in cutting through thick layers of doubt, ambiguity, and bullshit when discussing or evaluating any number of energy-related topics, from tiny to immense.
Conservation of energy is the kernel at the root of my argument in a previous post here that hydrogen won’t save us. By the way, that particular instance illustrates a particular challenge in evaluating any claim about energy: the system being evaluated must be closed. If the evaluation doesn’t encompass the entire system, it’s probably not valid.
Conservation of energy is beautiful for shortcutting around ambiguous and deceitful claims made by people trying to sell us on their latest (and always proprietary) devices, fuels, processes, etc. for free (or almost free) energy. If it walks and talks like a perpetual motion machine, then get out the waders, because it won’t work.
Now we get to the specific reason why I chose tonight to wax prosaic about conservation of energy. Take a look at an article I saw today on CNN (follow the linked text). edit 31 March 2019: I replaced the original link with an archive.org version.
First, let me say that I’m actually impressed with the article, because unlike most times when things like this happen, the article stopped short of actually claiming that this is anything more than a really interesting accidental experiment result. I want to keep an eye on this so I can see what the scientists learn from it. I’m also very interested to learn more about the work that this developed from: trying to use RF energy as a way to kill cancer cells. Interested students should read the article and note that the novel part of that isn’t the heating effect of the RF, but the implication that they might be able to seed only the cancer cells with the nanoscopic metal particles that facilitate the heating. That’s pretty interesting.
However, if all the information given as fact in the article is correct (particularly that the flame is wholly due to burning hydrogen), I have all the information I need to say that this experiment does not represent a way to use salt water as an energy source. How can I be so bold? Well, combustion is really just rapid oxidation with heat as an interesting side effect. The hydrogen combines quickly with oxygen, producing water and releasing energy in the form of heat. But… where did the hydrogen come from? It came from the water in the test tube. Somehow the hydrogen is being separated from the oxygen. I don’t know exactly what mechanism is causing this separation or exactly how the salt and the radio waves facilitate it. But, I don’t have to, because I know that this separation absorbs energy (just as the re-combination releases it).
Better than that, because of conservation of energy, I know that the separation of the hydrogen and the oxygen must absorb at least as much energy as is liberated when the hydrogen is burned. That energy must come from somewhere, and it’s not exactly a mystery. I would be willing to bet real money that if measured properly, there are measurably more joules of electrical energy going into the RF generator used in the experiment than there are joules of thermal energy coming out of the combustion of the hydrogen. It would almost certainly be more efficient just to take that same electrical energy and use it to produce heat directly using electrical resistance.
I realize that that’s pretty much a “duh” moment for most of my friends. Even the article itself references “skeptics” that say exactly the same thing (if more succinctly). I just wanted to subject you all to the little *squee* moment I have in my own mind every time I’m able to do this. 🙂
2 replies on “Conservation of Energy”
Hey – enjoy those “squee” moments. 🙂 We all deserve them. My personal obsession is efficiency. Nothing maddens me more than watching someone do something in a way that is not at all efficient. So, I can feel your pain (on a scientific level, of course). So, I get my “squee” moments when someone admits, “gee, it would have been faster/easier/less work to just do it the way you did.”
[…] course, we all remember how easy it is to show that this won’t work, […]