Imagine a computer the size of a solar system. For power, it would use a Dyson sphere—a solar array that completely surrounds the host star to collect almost all of its energy. That energy-collecting sphere would double as an ultra-powerful computer processor. Once the sphere had collected all the energy it needed, it would pass the excess to another larger Dyson-sphere processor that completely surrounded the first, repeating the process until all of the energy was being used. That's why this theoretical computer is called a Matrioshka brain: the nested Dyson spheres would resemble matryoshka dolls, or Russian nesting dolls.
Of course, if you surround your star with Dyson spheres, it would be difficult for life on your planet to continue. That's kind of the point: this Matrioshka brain would be so powerful that a species could upload their entire consciousness into it and live within an alternate universe simulated by the computer. The species itself could die and its planet could be destroyed, but the civilization would live on in a digital world identical to the one it left behind. In fact, many people, including Elon Musk, believe we're living in a simulation like that at this very moment. This provides one answer to the Fermi Paradox—that is, the question of why we haven't encountered aliens despite the likelihood that they're out there. It's possible that any civilization advanced enough to find us has already decided to abandon reality entirely and upload themselves to a Matrioshka brain. Delve deeper into megastructures and theoretical tech with the videos below.
How To Turn The Solar System Into A Computer
What's a Matrioshka brain, and how would it work?
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What Is A Dyson Sphere?
Find out whether this theoretical megastructure is even possible.
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Key Facts In This Video
In the future, we'll build larger and larger solar arrays until we enclose the entire sun in a cloud of solar satellites. This "cloud" is known as a Dyson sphere. 00:25
In 1960, physicist Freeman Dyson theorized that if future civilization could enclose our star in a rigid shell, we could generate 384 yottawatts (384 x 10^24 watts) of energy. 01:00
There are many problems with the concept. 01:33
Solutions To The Fermi Paradox
Maybe we haven't encountered aliens because they've already uploaded to a Matrioshka brain.