To Infinity and Beyond

“Infinite growth in a finite world is an impossibility” goes a popular quote. It is usually rolled out to illustrate that sustainability requires humanity to impose limits. Sometimes people then point to a specific element that they argue we will run out of in relatively short order, for instance phosphorus. I believe that this view is fundamentally wrong and ultimately dangerous. Instead, I propose a different motto “A finite world requires infinite growth.”

To explain my disagreement let me go back to a pivotal early moment in my personal development. I was about 8 years old or so when I learned in school that the sun, like all stars, would eventually exhaust itself and in the process first expand and then collapse, likely destroying Earth in the process but certainly making it uninhabitable for humanity. This insight resulted in an existential crisis for me. What is the point of anything, if everything will eventually disappear?

This may strike people as comical, after all we are talking about billions of years from now and there are so many pressing problems in the here and now, so why waste one second on the ultimate fate of the planet? But just ask yourself whether anything would matter, if you knew that Earth was going to explode later tonight. Yes, you might want to spend time with loved ones for mutual comfort, but it ultimately wouldn’t matter. There would be nobody left to remember. The only difference between today and the cosmic fate of the planet is time. And seeing this clearly, I spent several sleepless nights before realizing that humanity could carry on beyond that horizon by becoming space faring.

Ever since that moment, I have been thinking about what it means for Earth to be finite. Yes, Earth’s time is finite. But humanity’s time doesn’t have to be. It is also important to realize that the sun’s death is an upper limit on Earth’s habitability for humanity. There are many ways that could go away much sooner, from self-induced ones, such as the climate crisis or global thermonuclear war to external ones, such as a massive meteorite strike.

OK so maybe becoming space faring is some hypothetical way of dealing with the Earth’s finite life span. But isn’t Earth also obviously finite in terms of its resources?  And shouldn’t we be focused on that? People who like the first quote treat the resource finiteness of Earth as a given. As something that is self-evident.

And yet, any resource finiteness of earth, is strictly a function of the knowledge available to us. Why? Because we have access to extraordinary amounts of energy. A lot of it comes to us every day from the sun. And a lot of it we can release by turning mass into energy. We simply need to get much better at both of these. For solar this is entirely a question of deployment of existing technology. For nuclear it is a combination of building more fission but also of unlocking fusion.

We can have nearly abundant energy and that will let us do all sorts of amazing things (including collect more raw material from space). We can recycle materials to a much greater extent than today. We will even be able to transmute materials, i.e. turn elements into other elements. We know this to be physically possible, just requiring energies and processes that are far beyond present day capabilities.

So there are fundamentally two mindsets about the future. A pessimistic one where we see the Earth as finite in resources and conclude that we must limit ourselves. And an optimistic one where we see the Earth as finite in time and conclude that we must grow our knowledge towards infinity. The former mindset is not only uninspiring but will ultimately bring about human demise – with certainty, given enough time. We would knowingly be like the dinosaurs. The latter mindset points to a future of ongoing discovery. An exciting future of human growth and development. It this future that I argue for in my book The World After Capital.

I had been meaning to write this post for a while, but was inspired to do so by watching this video by Cleo Abram yesterday

PS Some people may point to the universe itself being finite and either contracting back into a singularity or expanding ever out into coldness. As it turns out, unlike the death of our sun, we don’t know nearly enough yet to understand which of these two scenarios will happen and it is also still possible that neither is the case. Also the relevant time scales here are absurdly large, although I grant that billions of years is a long time also ;)

PPS I am grateful to David Deutsch for his book The Beginning of Infinity which makes the case for the optimistic mindset