In principle, the Earth is a giant flywheel. In particular, there is an immense amount of stored energy in its angular momentum as it rotates about its own axis.

Theoretically it might be possible to tap into that energy, through some mechanism as yet uninvented. One intriguing aspect of such a mechanism is that it could be used anywhere, at any time. A motor powered by the rotation of the Earth could remain completely mobile and untethered, never needing to be recharged.

Of course, the moment you start tapping into its angular momentum, the Earth will start to spin more slowly. At first this slowing would be imperceptible, but eventually its effect on global climate would become catastrophic to life, both human and otherwise.

Therefore, to be an ecologically responsible species, we would need to continually “recharge” our planet by restoring its angular momentum. One way to do this would be via solar energy. We would need to devise some mechanism to translate heat from the Sun into a slow but steady “push” to keep the Earth spinning at the same rate about its axis.

In effect, such an energy ecosystem would be a form of solar energy, drawing on the Sun’s nuclear fusion energy, while using the rotation of the Earth as a form of temporary storage, in the form of a giant flywheel.

I’m not saying that this would be a good idea… 😉

8 thoughts on “Flywheel”

  1. I’m less interested in this as a way to deal with the energy requirements of human civilization, and more interested in the potential to eliminate the need for leap seconds.

  2. Good point! I wonder what the effect would be on our global climate if we were to speed up the Earth’s rotation just enough to eliminate the leap second.

    It would be interesting to calculate how much solar energy would be required to do that.

  3. According to wikipedia:

    The upper bound for annual solar energy usable by humans is about 5e22 J/year

    The rotational energy of the earth is about 2.138e29 J

    We’ve added 27 leap seconds in the past 45 years.

    Some pretty disgusting back of the envelope math tells me we would need to add about 9e19 J of energy to the Earth’s rotation every year in order to eliminate leap seconds. This is roughly equivalent to the power consumption of the United States. Totally doable!

  4. Considering that the process would be done with the goal of *stabilizing* the rate of Earth’s rotation, I don’t think the ecosystem would notice…

    However, I think the ecosystem would very definitely notice the fact that energy that would normally get reflected back into space is instead being collected… There are inefficiencies in solar collection, and there will be inefficiencies in moving that energy into the Earth, and I have a feeling all that waste heat would make our current rate of global warming look like a flat line.

    The solution to that problem may lie in the method used to accelerate the Earth, however… You can’t get around Newton’s Third, you can’t pull yourself up by your own bootstraps, you need to use reaction mass to do it. Use the collected energy to power railguns for firing mass into the western sky. While you’re at it, dump all your waste heat into the projectiles before you launch them and they will carry all that heat with them out into cold, uncaring space.

    The Earth gains about 40,000 tons of mass every year in the form of space dust, so as long as you can fire your railguns with enough energy to not need more than 40,000 tons of reaction mass per year, you break even.

  5. The next James Bond villain should just be a programmer who got really tired of implementing leap seconds.

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