In 1960, visionary physicist Freeman Dyson proposed that a complicated alien civilization would sometime give up playing around with kindergarten-level stuff like wind generators and nuclear reactors and eventually go huge, utterly enclosing their dwelling star to seize as a lot photo voltaic vitality as they presumably may. They’d then go on to make use of that giant quantity of vitality to mine bitcoin, make humorous movies on social media, delve into the deepest mysteries of the Universe, and benefit from the bounties of their energy-rich civilization.
However what if the alien civilization was… us? What if we determined to construct a Dyson sphere round our solar? May we do it? How a lot vitality would it not value us to rearrange our photo voltaic system, and the way lengthy would it not take to get our funding again? Earlier than we put an excessive amount of thought into whether or not humanity is able to this wonderful feat, even theoretically, we must always resolve if it’s well worth the effort. Can we really obtain a internet acquire in vitality by constructing a Dyson sphere?
Spherical Dyson cows
I’ll state from the outset that I am a theoretical cosmologist, not an engineer. I’ve completely no concept methods to go about constructing a bridge, not to mention a construction that reshapes the very face of our Photo voltaic System. However I’m prepared to guess that no one is aware of methods to have interaction in these sorts of mega-engineering challenges. We are able to’t say for sure what sort of advances through which applied sciences can be essential to construct a construction that even partially encloses the solar. To invest on that will be science fiction—enjoyable, however not very meaty.
What I do know, although, is physics, and there are some issues we will say concerning the physics of a Dyson sphere. We are able to use constructing one as a thought experiment to discover basic ideas of vitality, orbit, and movement. And that is essential as a result of it doesn’t matter what technology-so-advanced-it’s-indistinguishable-from-magic our descendants provide you with that permits them to tear aside planets, they nonetheless should face the chilly arduous realities of our physics. They will’t get one thing for nothing. In the event that they wish to resculpt a planet, that takes vitality. In the event that they wish to transfer a mountain-sized photo voltaic panel into a special orbit, that additionally takes vitality.
For these and plenty of different causes, a Dyson sphere prices vitality. So we’re going to see how lengthy it should take to recoup the vitality funding of constructing one and what the optimum design is likely to be to reduce the preliminary funding.
To get at some numbers, we’re going to make plenty of assumptions. Individuals wish to poke enjoyable at physicists for simplifying complicated issues, generally past recognition. The outdated joke goes that dairy farmers reached out to a close-by college to assist perceive why milk manufacturing was low, and the response from the physicists started by assuming that the cows have been spherical.
However there’s something highly effective about this simplifying strategy, which is why physicists are educated in it from day one. First, it lets us reply questions after we’re not considering exact numbers on the outset. Right here, we simply desire a normal sense of feasibility—will constructing a Dyson sphere take a (comparatively) small, medium, or excessive quantity of vitality? Second, simplifying the issue helps cowl up errors (both in calculations or our beginning assumptions). If all we’re going after is a normal ballpark, then a factor-of-two mistake (and even 10 or 100) received’t actually change the general intuitions our calculations allow.
Lastly, we actually don’t know methods to construct a Dyson sphere, so attempting to go for something extra complicated will merely result in us introducing many extra assumptions to deal with all of the small particulars. Every of these assumptions will enhance the uncertainty of any numbers we produce, and that uncertainty will in all probability find yourself buried within the evaluation quite than handily said upfront.
