Energy Conservation in Fiction


What do the Matrix and Black Mirror have in common? Well, both don’t adhere to the law of energy conservation. Let me explain why.

The law of energy conservation

Let’s start with a look at the law of energy conservation. From Wikipedia:

Energy can neither be created nor destroyed.

What does this mean? It says it is possible to change one form of energy into another, but not to create it or make it disappear. This law relates to energy in the broadest sense: heat energy, kinetic energy, atomic binding energy, etc.

If you hit the brakes on your car, the brake system uses friction to change the kinetic energy to heat, which then dissipates. A nuclear reactor changes molecular binding energy to radiation and heat. And so on and so forth. No energy is lost or created, just transformed.

The perpetual motion machine

In the middle ages, people thought that you could create a machine that moved forever. For instance, Mark Anthony Zimara designed a windmill that blew against itself to operate the millstone even if there was no wind. Leonardo da Vinci drew machines that he thought would provide free energy. Even today, the idea persists that this is somehow possible.

It is not.

The law of energy conservation above states that at best we could create a perpetual motion machine that runs forever, but without producing energy. If no energy leaks out of the system, it would keep running. If you could convert all the energy of a windmill to wind, and you could transfer all the wind’s energy to the vanes, then it would keep running. Only if no energy leaves the system (no heat, or motion, or light, or anything) will it keep going.

In practice, it is impossible to create a fully closed system, mostly because of the second law of thermodynamics.

But wait, what about gasoline? And the sun? What about nuclear power? All that energy comes out of nowhere, doesn’t it?

Nope. When you burn gasoline, you’re actually releasing energy from the sun, which was stored by plants, which was ground to oil over millions of years. Sunlight and nuclear energy come from nuclear fusion (or fission). In fusion and fission, the energy binding atoms together is transformed to heat and radiation. This is achieved by fusing atoms together (nuclear fusion) so they become elements higher on the periodic table, or splitting them (nuclear fission). The sun is just a big fusion reactor extracting binding energy by fusing atoms and transforming that energy into heat and photons.

In science fiction

Back to the Matrix and Black Mirror. In the Matrix, the robots have humanity enslaved in a virtual reality world. They do this so they can harvest the energy off of humans. Humans are fed the remains of the humans that die. A neverending cycle to power the robots… wait. Doesn’t that sound familiar? Yes, it’s another form of the perpetual motion machine.  The energy given to humans by feeding them would be  less than the energy that can be retrieved from them. It wouldn’t work.

In Black Mirror season 1, episode 2 “Fifteen Million Merits”, the world seems to have succumbed to environmental collapse and people are riding home trainers all day to generate electricity to power their lives. Again, this smells like a perpetual motion machine. The amount of energy produced by riding a home trainer is lower than that used to produce the food they require.

That’s just examples, but there are more. Keep this in mind when watching television shows and reading books. The laws of thermodynamics are violated there more than you’d think.

In fantasy

Fantasy is even worse than science fiction, although ‘worse’ isn’t the best term. Fantasy as a genre openly admits that it violates the laws of physics. Magic isn’t real folks.

It is interesting to note that often magic allows its users to create or destroy energy. In a lot of cases this could lead to the availability of unlimited power. That would have a huge impact on the world, although fantasy books usually don’t go there.

As an example, look at teleportation like in the Wheel of Time (they call it travelling). What the characters don’t seem to realise, is that if they put one end of their gateway in the water beneath a water wheel, and the other end above the wheel, gravity would pull the water through, powering the wheel forever!

Another example. If a human could really shoot a burst of energy at will like in Harry Potter, they could heat a neighbourhood if they set to it. Again: lot’s of violation of the laws of thermodynamics.


There are things you can see, but not unsee.

Violation of the law of energy conservation is one of those things. Now that you know, you might start to see it in many a show or book.

Martin Stellinga Written by:

I'm a science fiction and fantasy author/blogger from the Netherlands


  1. October 25, 2016

    What you miss is that in both of the cases you give the law of the conservation of energy is not violated, both are actually covers for a deeper plot in each which is not visible on the surface. The idea that the robots are using rebellious humans as batteries, not even a power source, batteries, is dumb. Orpheus states that the humans blocked out the sun to stop solar, but that still leaves wind, nuclear, orbital solar, geothermal etc, while anything from salt water to lead acid can be used as a much better battery. It is far more likely that the matrix is a cover for a neural network that the machines use to harness humanity’s creativity to aid their raw processing power.

    In the black mirror the bikes are clearly a make-work project to keep the masses busy in a post-singularity, post-industrial, post-scarcity world. With billions of unskilled people unemployed the only solutions would be genocide, imprisonment or revolution, and the powers that be clearly chose imprisonment. Surrounded by highly engineered products such as interactive TV walls, elevators, led lights etc it would be impossible for the economy to function with everyone producing power. Everything is clearly made by robots, the bikes might not even be producing power at all, as the flywheels don’t seem to be connected to anything and the upright post shows no wires, just welds.

    Don’t take science fiction at face value. If you see a law of nature violated it is more likely that your perception is flawed.

    • October 25, 2016

      I see your point, but Morpheus actually says it:
      Still, you could be right, and Morpheus was mistaken. However, what point in the story does that serve?
      With Black Mirror. Hmm, I hadn’t thought of it like that :). Have to re-watch it, I guess.

      The point I was trying to make is that it’s very easy to make mistakes with the laws of energy conservation. And while the Matrix and Black Mirror are awesome shows in any case, many other shows and books are not. Even worse, these mistakes can start to lead a life of there own, convincing people that we could solve global warming by everybody riding energy-producing bikes.

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