Pick a population growth rate and I can tell you when the minimum possible power used to keep each person’s consciousness running at 100% speed even if you strip away all the messy biology and just function as a uploaded mind on a perfect computer, still exceeds the fundamental capacity of the universe.
Of course it may turn out there’s “One Weird Trick To Make More Matter And Energy In The Universe While It’s Expanding (Physicists Hate Him!)”, but that’s not something one can foresee, because if you could foresee that kind of thing reliably we’d already know about the trick.
>Pick a population growth rate and I can tell you when the minimum possible power used to keep each person’s consciousness running at 100% speed
I'm not sure which definition of 'growth' you're referring to here. If it's GDP (which the article linked earlier did), well, in many developed countries, population has been decreasing despite increasing GDP. So this issue does not prevent growth.
But lets assume we're talking about population size, and assume also population keeps increasing:
We don't have to run consciousness continuously. Since consciousness is now virtualized we can suspend it and make it appear to the person as if they never were suspended (or 'slept' if you will). e.g. give a tick every thousand years. If needed, we can increase the period. And if we synchronize everyone, nobody will notice. I daresay it's possible to maintain a large population indefinitely using this method.
> I'm not sure which definition of 'growth' you're referring to here.
One in which brain uploads are relevant, because you mentioned it.
Literally any kind of efficiency has a maximum, an economy of pure minds was just the most extreme case which I took specifically to avoid any possible debate: there is (according to currently known laws of reality) definitely an absolute maximum in this universe, no matter what we do.
Limit the population to current number or lower, and any other kind of efficiency also has a limit — lights can’t convert less than 0% into heat, resistance can’t be less than in a superconductor, reversible computers can’t beat the Landauer limit.
You might fully automate manufacturing and give everyone alive today their own personal galaxy cluster [0] and it’s still finite.
Big, still finite.
> If it's GDP (which the article linked earlier did), well, in many developed countries, population has been decreasing despite increasing GDP. So this issue does not prevent growth.
Indeed it is decreasing. Yet you may have to enforce that, because subgroups that grow faster rapidly dominate. This is unavoidable unless you take active measures to prevent it, because that’s what evolution does. (You can because evolution is dumb, but you have to).
(I’d argue that in such a case, the license to reproduce would constitute a currency and in that currency humanity today world seem unimaginably wealthy; however this is not something I am prepared to make a keystone argument).
> We don't have to run consciousness continuously.
Can also just run them all slower.
In neither case does this sound like an economy “growing” to me, but let’s say it is:
Still only a finite quantity of stuff in any given light cone upon which to record the state.
In the extreme case your storage is multi-AU wavelength photons on the edge of turning into a Kugelblitz black hole after all the stars have gone dark and the CMB has redshifted beyond detectability, and that’s still finite.
I’m happy to believe that in my lifetime we’ll develop the tech to begin turn Mercury into a Dyson swarm and directly colonise half the accessible universe [0], but it’s still finite, there’s still a limit.
Exponential growth hits even big numbers much faster than most people expect.
You ever played an idle game? I find them annoyingly compelling, but they all seem to show this behaviour, rapidly getting into numbers much larger than quantities of any category of stuff in the real universe.
>Yet you may have to enforce that, because subgroups that grow faster rapidly dominate.
We don't see this in developed states today. Unless increasing costs of childrearing is its own way of creating a limit.
>Still only a finite quantity of stuff in any given light cone upon which to record the state.
But we're not going to reach that limit. For each increase in population*, we can increase the suspension/decrease speed and no one will even be able to notice.
Growth is 'infinite' here inasmuch the growth function is monotonic - but it's asymptotic, and the total energy expenditure is always finite.
Also, we're talking about such a huge timescale, one wonders what people will discover that could upend our picture of the universe.
* Which again, doesn't have to happen under the definition of growth the article used.
Of course it may turn out there’s “One Weird Trick To Make More Matter And Energy In The Universe While It’s Expanding (Physicists Hate Him!)”, but that’s not something one can foresee, because if you could foresee that kind of thing reliably we’d already know about the trick.