NOTE: Today’s excerpt from World After Capital dives deeper into human knowledge and why it is so powerful.

Have you watched television recently? Eaten food that had been stored in a refrigerator? Accessed the Internet? Played games on your smartphone? Driven in a car? These are all things that billions of people around the world have access to and often use daily (there are over 2 billion smartphone users). Many of us take these capabilities for granted and rarely do we ask where they come from. And while these are produced by different companies using a wide range of technologies, none of them would be possible without the existence of knowledge.

Knowledge, as I use the term, is the sum total of all information humanity has recorded in a medium and improved over time. There are two crucial parts to this definition. The first is “recorded in a medium” which allows information to be shared across time and space. For instance, stone tablets were some of our earliest ways of recording information. The second is “improved over time” which separates knowledge from mere information, provided that the process of critical inquiry is allowed to operate (we first encountered this process in the chapter on Humanism).

A conversation I had years ago but didn’t record cannot be knowledge. However, if I write down an insight from that conversation, or even the conversation verbatim, and publish it on my blog, I’ve potentially contributed to human knowledge. The conversation isn’t accessible to anyone who wasn’t there at the moment it happened. Even my own recollection of the conversation will fade. The blog post, by contrast, is available to others across space and time. Some blog posts will turn out to be important and become part of human knowledge. As another example, the DNA we carry in our cells isn’t knowledge by my definition, whereas a sequenced and recorded genome can be. Every person’s DNA sequence is ephemeral, i.e. disappears with our bodies. Recorded sequences though can be maintained over time, shared and analyzed. Ones that turns out to be medically relevant, such as the BRCA mutation that increases breast cancer risk, become part of human knowledge.

This definition of knowledge is intentionally broad and includes not just technical and scientific knowledge but also art, music, literature. But the definition is also narrow in that it excludes anything that is either ephemeral or not subject to improvement. Computers these days produce tons of recorded information, such as logs of activity on a system, that are mere information, unless they are subsequently analysed.

I started this section with examples of everyday technologies that would not exist without the power of knowledge. An even stronger illustration of its power is that without knowledge many of us would not be here today. As we saw in the chapter on population, Malthus was right about population growth but wrong about its most dire consequences because he did not foresee technological progress powered by knowledge. It is useful to go through one specific example to show just how powerful knowledge is and how it improves over time.

Humans breath air. But for the longest time we did not know what air consists of. Both oxygen and nitrogen, the two primary components of air, were not identified and isolated as elements until late in the 18th century (around 1770). Separately the systematic study of manure as a fertilizer, which had been used in agricultural practice dating back to Egyptian and Roman times, didn’t start until the early 19th century. That study led us to understand that ammonia, which consists of nitrogen and hydrogen, is a powerful fertilizer. Progress in chemistry and industrial processes eventually resulted in the so-called Haber process for nitrogen fixation, which means converting atmospheric nitrogen into a form that can be available to plants. The Haber process, which was invented in the early 20th century, became a crucial ingredient in raising agricultural yields globally and thus averting the Malthusian dystopia.

How successful has this been? For most humans today, about half the nitrogen in our bodies has been touched by the Haber process on its way into plants and animals that we subsequently ingest. Put differently: knowledge is so powerful that we are now made from knowledge.

What my much compressed history of nitrogen fixation doesn’t capture are the many false starts along the way. It seems hilarious to us now, but at one point a leading theory as to why some materials can burn had nothing to do with oxygen but was attributed to the material containing “phlogiston” which was thought to be the part of the material that “disappears” into the air when burning. Without the improvement of knowledge over time, we might have remained stuck at that theory.

When thinking about the power of knowledge, we must remember that a year, or a decade, or even a hundred years are all trivial in the time scale of humanity, and in turn, humanity’s time scale is trivial compared to that of the universe. When considering longer time frames, we should regard as possible all speculative propositions that don’t explicitly contravene the laws of physics—a line of thinking inspired by a new theoretical foundation for science called Constructor Theory [57].

Consider for a moment what knowledge might allow humanity to do in the future. We might, through further discovery, rid ourselves of fossil fuels, cure any disease, take care of every human’s basic needs, and travel to other planets in our solar system (organizations like SpaceX and NASA are already working toward this goal [55]). Eventually we might even travel to the stars. We could, of course, also blow our own planet to bits before any of that can happen or be struck by a massive asteroid (this is why allocating our collective attention properly is so crucial). Now, you might say: “Travel to the stars? That’s impossible.” Actually, it isn’t. Extremely difficult? Yes. Requiring technology that doesn’t yet exist? Yes. But impossible? No. Interstellar travel is definitely not imminent, but with the further accretion of knowledge, it will become possible.

Knowledge is the essential human project. We are the only species on planet earth that has created knowledge. This is also why I include art and music in my definition of knowledge. Art has allowed humans to express our hopes and fears, and its accretion into culture has helped motivate the large scale coordination and mobilization of human effort. We can broadly think of technical component of knowledge as underpinning the “how” of our lives and the artistic component the “why” And if you have ever doubted the power of the art portion of knowledge, just think of the many times throughout history and the present when dictators and authoritarian regimes have banned and destroyed works of art.