This is a guest post with detailed notes by my friend, Sean Legler.
Scale: The Universal Laws of Life, Growth, and Death in Organisms, Cities, and Companies was a book fascinating at times but which really ought to have been scaled down to about one-fifth the length. Moreover, Mr. West hits you over the head about 100 times with the thesis of applying math to biology as a transformative 'new' idea, which really isn't new, but that's okay. Alas, to scale down your time commitment needed to benefit from this thought-provoking book though, here are some notes I made:
SUPERLINEAR AND SUBLINEAR SCALING
- There can be increasing returns to scale, which is called superlinear scaling. Bigger cities will have superlinear increases in economic activity, patents, salaries and culture. If you double the city size, you get more than double back. There is simply more opportunity in a large city, which arises from the benefits of density. This can be seen in distributing resources and energy more efficiently and from increasing potential person-to-person interactions. Unfortunately though, there are also superlinear increases in crime, garbage, AIDS and other inconveniences. As an editorial aside: it seems perhaps the ideal is to live part-time in a city and part-time in a smaller community to get the benefits of both.
- Next, the other scaling type is sublinear scaling, in which less and less of something is needed with greater scale. For example, cities will have sublinear scaling of gas stations (i.e. you need fewer gas stations per person due to density benefits). On the biological side, there is more efficiency to larger mammals in terms of their basal metabolic rate, which is a sublinear scaling of energy use. An elephant uses a calorie better than us puny humans through their gains in efficiency from their scale. However, you eventually run into other scaling law counterbalances that check the size of what is possible for an organism. For example, bones of a certain type could not support ever-increasing weight. Your food consumption also could not keep up with the energy needed for an ever larger superorganism. Many large mammals alraedy spend a great portion of their waking hours just eating to keep up with their calorie needs.
- Life 'speeds up' in cities with more interactions and things to do and places to go. Literally, people apparently have been measured to walk faster in larger cities. Liverpool has even made fast walking lanes because 47% of the UK finds slow walking the most annoying aspect of street shopping.
- The larger the city we live in, the less close attention we pay to others. Our attention is diluted and it is simply not sustainable to say hi to everyone you walk by in NYC.- Interestingly, social network sizes are not all that different amongst different city sizes. Yet in a larger city, your ~150 meaningful contacts might know fewer of your other contacts. In a smaller town you might actually have the same number of folks in your circle that you interact with on a regular basis, but more of your small town folks-not surprisingly-know each other. To me, this makes it seem like there is more opportunity for creativity in a larger city with more unique second-hand connections. Yet this creativity likely may come at a loss of a sense of community. Again, a mix of small town life and city life sounds great.
- Importantly, social networks still need physicality and cities provide this. If they are to thrive, cities need to enhance and facilitate social interactions because that is where a lot of their magic comes from. Moreover, we are physical beings and we still need to get from place to place (this book was written before the pandemic but overall still true), and so cities are better for this where things are literally closer together and you can see more potential people and places more easily.- Of practical significance on a warming planet, it is arguably more environmentally friendly to live in a city and in an apartment building in which superlinear and sublinear scaling benefits can help you use less energy. You share resources and infrastructure with others versus everyone having their own McMansion, their own long driveway, their own pipes and plumbing, their own cars, their own exercise equipment, etc.
- Human bodies use 2000 calories a day which powers 90 watts. 90 watts is like a standard light bulb. That's incredibly efficient. Whales meanwhile need a million calories a day (400 times more than us, or 400 light bulbs) and are even more efficient on a per calorie basis.
- However, while we use 90 watts or 2000 calories of internal energy within our bodies, externally (via modern technology and our consumption of resources) we may use 11,000 watts on a given day as average Americans. This is 100x our natural energy consumption and the equivalent of a dozen elephants' daily energy needs. So for every person you see on the street (at least in America), you can imagine a dozen elephants trailing them and eating up resources on the planet.- Larger mammals tend to have lower rates of cancer, perhaps from more efficient use of energy
- End to end, our circulatory system encompasses 100,000 km.
- Almost all mammals have approximately the same number of heart beats in their lifetimes. This is because the longer a mammalian species tends to live, the slower their heart beats. As a result, most of us mammals get about 1.5 billion heartbeats during our time alive on Earth. Unfortunately for the smallest shrew though, they use up a 1000 of their heart beats in a minute.
- Blood pressure is approximately the same across mammals too- We love the idea of Godzilla, but he is impossible, at least under current biological structures that have evolved, and so you would need to change many of the foundational biology that has evolved first (protein types, mitochondria etc.). You can't just scale up lizards (thankfully!).
- A company half life is 10 years. Unlike cities, many companies do not last that long. We overestimate their longevity and permanence.
- Of ~1000 companies over 200 years old in the world, half are Japanese. The oldest company known (over a 1000 years old) went out of business recently. It was a Japanese Buddhist temple building company.
- Fractals: how you measure coastlines and borders matter; the smaller the unit of measurement you use between points, the longer the coastline or border will be.
- One principle of many scaling systems is that they are inherently space filling. You need to have arteries physically going to every physical component space to each terminal unit. A second principle is that you have often have similar terminal units (e.g. electrical outlets, faucets, cells, or employees) that all need to be communicated with. A third principle is that you need to pump substances through space to get things to the terminal units. You need to distribute energy and communications through space and you need to distribute them in such a way so that the least amount of energy is wasted along the way. Your goal is that you need to ensure that this distribution system and your use of space is used in the most efficient way possible (at least if you want to outcompete other evolving systems and not go extinct).
- Cars look more alike now due to aerodynamics for fuel efficiency. Back in the day, car manufacturers didn't have the demand for fuel efficiency like they do today and so you had more unique designs out there. They didn't have aerodynamic scaling pressures in mind to the same extent and they weren't all sharing the same math equations to minimize drag forces like they do now. As a result, we have a more homogenous-but at least fuel efficient-set of cars to buy.
- Ultimately, to battle the indefatigable process of entropy you need a constant supply of energy. Mr. West argues that how you distribute and use your energy matters much more than we realize and that how we do so depends on scaling laws. Scale affects how we utilize energy, and energy is the great currency of physics and life. Whether there is infinite energy for us to battle entropy forever is another conversation (and why you should read poetry in addition to physics books).
- Lastly, I did appreciate that Mr. West frequently complimented all his colleagues and interns that he works with around the world and at the Santa Fe Institute throughout the book.
May the scaling laws be ever in your favor.