What catchy title for a post uses the word thermodynamics?

Understanding thermodynamics can help you in the world (seriously). There are four laws of thermodynamics, but one and two are most interesting. They are paraphrased below:

Law 1 - Energy cannot be created or destroyed, it can only change form.
Law 2 - When changing form, some energy is always lost as waste heat.

Put another way: "Not only can you not win, you can't break even."

Practical application #1
I read a story about a plan to put wind turbines near a highway to try and recapture the wind created by the fast passing cars. Sounds like a great idea, right? Use Law 1 above and tell me what is wrong with it.

Where does the energy come from? When the highway is empty, the wind turbine won't turn, so the cars must be providing the energy. And that is exactly what they found when they tested it. The fuel efficiency of each car was found to be reduced slightly. The energy created by the cars was being changed from mechanical energy (motion of the car) into wind energy (motion of the air molecules) into mechanical energy (motion of the turbine) into electrical energy.

The worst part is, as Law 2 states, every time you change form, you waste some energy. So you are basically burning gasoline to create electricity, but in the most inefficient way possible. It is sort of a Rube Goldberg contraption of idiocy.

So you may be asking yourself, "Where exactly is the practical application of thermodynamics you promised?" And here it is. You can yell at the monitor when you read these types of dumb ideas and your partner and/or dog and/or fish and/or D&D action figure can nod their head at how smart you are. Or maybe shake their head at how crazy you are. I'm not sure.

Practical Application #2
If the 1st practical application wasn't enough, here is a second one, which actually involves money and prison!

I had a co-worker pitch an idea for an invention to me. He said that his brother-in-law had a patent for a machine that could generate energy very cheaply. It was made from an outer hub with seven magnets, which was attached to an inner ring with .... (he paused and looked around, like he was about to blow my mind and didn't want any other minds around us to blow -- no collateral mind blowing) six magnets. "Because the magnets are spaced like that, the hub magnets are always pushing the ring magnets around, like a merry-go-round that never stops."

I'm sure you've all heard of perpetual motion machines. Now contrary to popular belief, the US Patent office will not reject the filing of a patent just because it is for a perpetual motion machine. However, it does stipulate that a working model must be provided before the patent will be granted. Needless to say, that has never happened.

Here's the thing. It is possible to build a "perpetual" motion machine with magnets. The reason is magnets do have energy in them, so as the machine moves it will slowly weaken the magnets. This obeys Law 1. However, taking the final step and trying to generate electricity from it can be a tricky step. Law 2 says that every time you try and change the form of energy, you piss some of that energy away. So the very act of hooking up a generator to your spinning 13 magnet science project will cause it to either spin slower or maybe weaken the magnets faster. In any case, you are just using the magnets like batteries and they will eventually die out, requiring you to get more magnets.

You may have been waiting for the money and prison part. Here it is. My co-worker told me about this incredible invention and asked me if I wanted to invest in it. His brother-in-law was selling stakes in the company, which could be "worth millions". I explained how perpetual motion machines were impossible without an energy source. My co-worker looked at me, and then tried to explain the 6 magnet / 7 magnet configuration again. He even produced a sketch on some graph paper which "proved" it. Did I mention this co-worker had a degree in Engineering? I politely looked at his sketch and explained that you couldn't violate the first or second law of thermodynamics, which this idea clearly did. I warned him that he should not invest, and should explain thermodynamics to his brother-in-law next time they meet. "Well, I won't be seeing him for a while. He's in prison on fraud charges." I got up and slowly backed out of his office, which was a surprisingly awkward way to leave an office.

Moral of the story: There is no thermodynamic law against being a moron.

PS. I swear to dog this story is true.