How could the economy work, if we were in a future in which you could convert the mass of matter into energy and vice versa with extremely high efficiency (around 99%)? This question comes from my thoughts about my latest sci-fi world Canonical Coherence (formerly “Universally Advanced”), because in that world this kind of matter-energy conversion is actually possible.
Materials vs Virtuals
More specifically, this question arose from the comparison of virtuals, AIs / whole brain emulations run on a synthetic computational substrate, only interacting with the real world via avatars / surrogates and other tools, and materials, humans and other beings who use a material body with its own mind generating unit (aka brain). It shouldn’t be surprising that virtuals require way less matter to operate than materials. You could have a million virtuals for every material, or more. Similarly, the energy costs for sustaining a virtual would we way lower than those for a material, who needs to sustain their whole body and brain.
Obviously, virtuals have a huge comparative advantage: The low basic living costs. There would be a big economic incentive to switch to a virtual existence, in order to save on living costs. This could be countered by covering those with a basic income that covered living costs, depending on how big they are for the specific mode of existence. But that wouldn’t be a homogenous universal basic income. And it would be a pretty significant subvention for the materials, with the virtuals covering most of the costs (if we assume that they are responsible for most of the economic activity). Nevertheless, there might be good reasons for the virtuals to support such a basic income, especially if they want to keep the option to switch to a material body open for themselves, or if they are fond of “material culture”, in a fashion that is not too dissimilar from today’s people fondness of nature and natural wildlife.
Mass as universal currency
Using energy as universal currency has already been suggested, but that suggestion comes with the problem of different energy prices in different regions. But using matter as universal energy storage would solve that problem, if extremely efficient matter-energy-conversion technology was available ubiquitously. Matter would become the equivalent of gold coins that were accepted everywhere. The kilogram would be the universal currency unit that all other economic assets would be measured in. And it would hardly matter what kind of matter we were talking about, since compared to the mass energy of matter, chemical and even nuclear energy are comparatively negligible. A kg of platinum would be worth pretty much the same as a kg of fat.
Transporting matter itself to make financial transaction would be a little bit inconvenient. Therefore, people would very quickly abstract from pure matter and introduce a currency that is simply backed by the claim to get matter of a specified mass at certain locations. Let’s call those claims “mass credits”. There would of course a need to take measures aimed at preventing the forgery of mass credits. Similarly, a fractional reserve banking system with mass credits might not be desirable, since it would break the strict correspondence of mass credits to actually existing mass that someone could have always enforceable claims to.
Mass is energy
Since mass is convertible to energy, it would be equally justified to talk about energy credits. You could pay most of your energy bills by selling a few fractions of a gram of matter. The mass energy of a gram of matter roughly corresponds to the energy released by the “Litte Boy” atom bomb that was used to nuke Hiroshima during the WW2.
The sun’s energy output
Our sun has a power output of 3.8 x 10^26 W, or 3800 trillion trillion Joule per second. How much would that be in mass? That would be 4.2 billion kg per second. If we could collect all of that energy and grant every human being a corresponding income in mass credits, that income would be about 0.5 kg per second, or 500 Little Boy explosion equivalents per second.
Assuming we could increase out population by a factor of a trillion, everyone would could still get an income of 0.5 nanogram per second, or about 16 mg per year. That would be enough to cover even excessive energy bills, but you would have to save for millions of years in order to be able to afford a human physical body. Actually, that wouldn’t matter too much, since the mass of a trillion billion people is less than half of a billionth of the sun’s mass (2.0 x 10^30 kg). And the sun isn’t especially efficient at turning its mass into energy anyway. We would be better off, starlifting (see video below) the sun, and converting its matter into energy directly!
Actually it would be reasonable to starlift a fraction of the mass of our sun to make a Dyson cloud of desired and use the rest of its mass energy to keep it running for billions, trillions, or even quadrillions of years (the exact number would obviously a hot political issue).
But all of that is still a money based economy
Yes, to some it will certainly see absurd that we will still be using some kind of money in a world in which we have the technology for extremely efficient matter energy conversion (and probably also “replicator” technology). It is quite possible that money would be frowned upon, especially once much more sophisticated economic systems will have been developed. But you could see mass credits as fall-back layer, or underlying matter economics layer, that could be used where more sophisticated methods of dealing with economic issues seem inappropriate, for whatever reasons.