At present there is no solution to the dark energy problem. Prominent physicists like Ed Witten have called it the greatest embarrassment of theoretical physics. It has forced physicists back to the drawing board—all the way back to the foundations of quantum mechanics and general relativity. And for me and Jaron Lanier, that meant quantum computers.
Gravitonic topological alien computers! Recall the image of the many copies of a quantum abacus, distributed across many realities, all working in parallel. When we move to topological abacuses, where the wires can be tied into loops, trees, knots, and so on, what is going on in all those parallel universes? There is an interesting divergence. On one hand, there can be a bead that is jiggling between the up and down positions on a wire. But although topological quantum computers would rely on changing the shapes of the wires, the shapes themselves are definite. They cannot jiggle themselves into loops that are simultaneously open and closed, in what you might call “sort of loops.” A wire is either a loop or it isn’t.
The interesting thing to notice is what happens if you superimpose all the versions of a quantum abacus from the various realities it’s in. The superposition changes depending on the role that topology plays in your computer. The complexity of a nontopological (nonknotted) superposition is linear, which means simply that it’s exactly as complicated as you’d expect from summing up the complexity of its parts. If, however, you superimpose knotted, topologically interesting abacuses, the result will not be linear, because not all the intermediate states are possible. If you superimpose a loop and a nonloop, you don’t get a distribution of possibilities including a “sort of loop.”
Now recall that we just mentioned something else that isn’t linear: relativity. Space-time is curved, not linear. The quantum state of gravity, which can be thought of as the superposition of the quantum abacuses that either are or describe (depending on your philosophical preference) the state of space-time and/or gravity in the universe, is not linear. Could that be because gravity’s abacuses are knotted?
So here’s a scenario of what might have happened in the history of our universe. These days, we take matter for granted as a dominant component of reality, but when the universe was younger, it was too hot for matter to be commonplace. Eventually the universe cooled down and matter became an important phenomenon. With matter came chemistry, and with chemistry came life and evolution, leading to smart aliens who experienced their own Moore’s laws, which drove them to develop gravitonic quantum computers.
As it happens, the amount of dark energy in the universe reduced rapidly just as matter became important. In terms of our thought experiment, that was not a coincidence. It was because the aliens used dark energy as a resource to run their ultimate computers in much the same way we devour oil to run our cars and jets.
Before we continue, there is an even more daunting issue that sneaks up on anyone who tries to explain away the cosmological constant/dark energy problem: Why now? I had tried to tackle this when I was at Stanford. The surprising thing is that today the cosmological constant/dark energy is not zero but proportional to the dense matter; it seems to be tracking the amount of matter. The …….
Source: https://www.wired.com/story/so-what-if-aliens-quantum-computers-explain-dark-energy/