It’s been more than a decade now, since we realized that this Universe is probably doomed to be ripped apart by a powerful force, named dark energy.
We don’t know exactly when, but it will most probably happen in the span of the next trillion years. The anti-gravity of dark energy will destroy even black holes and atoms, which would otherwise stay around for many orders of magnitude longer. Now this scenario will unfold suddenly, our Universe will die in its early infancy, even before all the stars will have exhausted their fuel.
Well, not so fast! There is a way to convert dark energy into ordinary matter-energy. In principle, there is nothing that would prevent us from converting nearly all of it thereby creating twenty times as many galaxies, stars and planets that we currently have. Okay, maybe in some other form of mass-energy, but that’s secondary.
There is little to no dispute about using a rope from here to a distant redshift galaxy and using the resulting force to do some work – a tiny amount, but still.
And we can do it better, much better: instead of a trans-galactic rope, we could use two distant black holes, falling toward each other. Thanks to dark energy, new space is constantly being created between the two. So there is virtually no limit to at how close to the speed of light they will eventually crash. Not exactly at the speed of light, but arbitrarily close.
This means, that their relativistic speeds will give them an arbitrarily large mass, therefore relativistically multiplying their masses a million times. They could, if there was an unlimited supply of dark energy around. But there isn’t, because we used it and converted it to ordinary mass-energy in the form of a massive black hole.
Perhaps we don’t even need two black holes and a long linear particle accelerator would do. Perhaps we could use dark energy induced space inflation to make a proton to travel at 0.999 of the speed of light – instead of only 0.99 with the same energy input. The difference could only have come from the conversion from dark energy to ordinary mass-energy.
All the above only holds true in the case of the law of Energy Conservation being extended to dark mass and dark energy in the future Quantum Gravity Theory, and that some crucial aspects of General Relativity remain valid.
In that case we will be able to change the fate of the Universe, to make a closed one, from an open one.
It is possible, that some converting processes are already under way naturally. This wild acceleration only begun 5 billion years ago. It started naturally, it may end the same way.
Even if it is us who stop it, it will still be all natural.