Readers React: Making gasoline out of air? Sounds like a perpetual motion machine

To the editor: Making gasoline from carbon dioxide to power your car is a new twist on a perpetual motion machine, which has been a dream for many backyard inventors for centuries.

The idea is that, with the right setup, something can run forever. In this case, the hope is to run a car forever by turning gasoline into carbon dioxide and then back to gasoline.

There are several known chemical pathways to transform carbon dioxide into gasoline. Problem is, it takes a lot of energy to do this. If the energy comes from the sun, the process would be very slow. If it comes from electricity, one has to plug in the car, and we already have electric vehicles. If the energy comes from fossil fuel, what is the point?

All perpetual motion machines fail because of three unbreakable laws of thermodynamics. In layman’s terms, they state that in the energy game, you can’t win by getting more energy than what you start with, you can’t even break even by not losing useful energy, and you can’t get out of the game, because it’s impossible for these rules to be broken.

Evan A. Thompson, Altadena

The writer holds a doctorate in chemistry.

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