The governments of the world today are at a crossroads. We can either continue to burn through the planet’s fossil fuels or search for new forms of energy. The so-called “energy crisis” threatens to be one of the greatest challenges civilization will face. There are a lot of issues at play, from the limited nature of oil to the well-being of the planet. However, the current energy crisis pales in comparison to what might be in store for humanity in the future. After all, no matter how much oil we use up, we can always depend on the Sun. That is, until we can’t.
The Sun is a powerful object, radiating far more energy every second than our entire nuclear arsenal. And yet, the Sun is only an average star, a yellow dwarf in the middle of its 10 billion year lifespan. It is essentially a gigantic, stable fusion reactor. If we could tap into that vast reserve of power, all of our concerns over energy would be eradicated for a few billion years. Right now, a teeny tiny itty bitty fraction of the Sun’s output reaches earth and an even smaller fraction of that energy is used by us humans directly (we use a lot more of it indirectly when we eat food). One day, maybe humanity will realize the enormous potential of the Sun and begin gathering its energy from every angle, building a Dyson Sphere to capture all of the raw power.
Although the Sun will last for billions of years, pumping out a vast amount of energy, it is by no means a permanent solution to humanity’s energy needs. All things in the universe inevitably decay. The Sun is no exception. The second law of thermodynamics eats its way through everything and entropy will eventually catch up to the Sun. What then?
Of course, the Sun will last for a few billion more years before it becomes a red giant and swallows the Earth, so we have some time to come up with solutions. First, assuming there are no devastating asteroid impacts, humanity will eventually be able to travel amongst the stars, building other Dyson Spheres along the way. At that point, the Sun’s death will be a mild inconvenience. Civilization will spread outward, soaking up the energy of thousands and thousands of stars. This will be the heyday of the human race.
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Unfortunately, our old friend entropy doesn’t give up so easily. Sure, some new stars form from supernovas and leftover stardust over time, but each new “generation” of stars becomes smaller and smaller. Fewer and fewer new stars will be created over time and the universe will begin to grow dark. The last vestiges of any civilization will be huddled around red dwarfs, the longest lasting stars in the universe. What little energy they put out, society will have to make due. Time will keep ticking and when the last white dwarf grows dark, we will have no more useable energy. Game over.
With this grim news, is there any way to reverse the flow of entropy, to make all of that unusable energy useable again? This idea has been the topic for a few works of fiction, most notably “The Last Question” by Isaac Asimov. Asimov’s short story chronicles humanity’s rise and fall in the universe as people ask their machines how to prevent the inevitable decay of the universe. In the book, this “last question” is asked for the first time in 2061 by a drunk computer technician, leading to an endless stream of people over billions of years asking the same question to increasingly sophisticated computers. The answer is always the same. After the last human merges with the Cosmic AC (a computer built from billions of years of auto-evolution in artificial intelligence) in hyperspace, the AC spends an immeasurable amount of time solving the question and then recreates the universe, proclaiming, “Let there be light.” Never before or since has a story looked at this inevitable issue with such depth. The realistic writing and tone of the narrative originally sparked my initiative to write this article on entropy’s inevitable destruction of the universe.
With both the fictional last question and the inevitable decay of the real universe in mind, then how do we solve the entropy problem? I don’t know. I find the concept of entropy more poetic than destructive. The universe is a stream and entropy is its current. We live in a tiny eddy created by the Sun’s energy, but that rock will eventually be eroded away by the swift current. I am the furthest thing from a physicist, but I doubt even the best minds in physics know much about the solution either. The best I can think of is to travel to a younger universe before we run out of energy, but that is mere speculation on my part. In closing, regarding the final energy crisis of civilization, “THERE IS YET INSUFFICIENT DATA FOR A MEANINGFUL ANSWER.”