Scale: The Universal Laws of Life and Death in Organisms, Cities and Companies

by Geoffrey West

the basic units inside mitochondria where ATP is manufactured, to show that the number of times the reaction takes place producing ATP is the same for all mammals.

incurred per cell, resulting in larger animals living longer. However, within species an individual like each of us can decrease its cellular metabolic rate simply by eating less, resulting in less metabolic damage per cell and potentially in an increase in its life span. This strategy is called caloric restriction. It has a long, somewhat

Taken at face value, the theory predicts that if you consistently decrease your food intake by 10 percent (a couple of hundred calories a day) you could live for up to 10 percent longer (up to ten years more).

Having taken two million years to reach a population of a billion, the next billion took only another 120 years, and the one after that took less than 35. Doubling that took just 25 years, reaching 4 billion in 1974, and at present, only 42 years later, we have almost doubled that again with a global population now in excess of 7.3 billion people.

our greatest invention has been the very stage upon which this panoply of socioeconomic interactions, mechanisms, and processes that drive exponential expansion has been played out, namely the city.

The Triumph of the City.

Cities are the crucible of civilization, the hubs of innovation, the engines of wealth creation and centers of power, the magnets that attract creative individuals, and the stimulant for ideas, growth, and innovation.

But they also have a dark side: they are the prime loci of crime, pollution, poverty, disease, and the consumption of energy and resources.

Rapid urbanization and accelerating socioeconomic development have generated multiple global challenges ranging from climate change and its environmental impacts to incipient crises in food, energy, and water availability...

Suppose we start the growth process at eight o’clock in the morning and have carefully calculated that there are just sufficient nutrients to ensure that the container is completely filled with bacteria by exactly twelve noon. Here’s the question: at what time between eight a.m. and noon is the container half full? Those who get the wrong answer typically suggest a time over halfway between 8:00 and 12:00, such as 10:30 or 11:15. The correct answer, which comes as a surprise to some, is 11:59, just one minute before noon. I’m sure you’ve got it: since the population doubles every minute, it must have been half of its final size just one minute before the process ends at noon, which is 11:59 a.m.

Thomas Robert Malthus is usually credited with being the first person to recognize the potential threat posed by open-ended exponential growth and connect it to the challenge of resource limitation and availability.

His argument was that the population “multiplies geometrically,” meaning that it increases at an exponential rate, whereas the ability to grow and supply food increases only “arithmetically,” meaning that it increases at a much slower linear rate, so the size of the population will eventually outstrip the food supply, leading to catastrophic collapse.

The Population Bomb,

Ultimate Resource that

endogenous growth theory, which holds that economic growth is driven primarily by investment in human capital, innovation, and knowledge creation.

every generation has underestimated the potential for finding new recipes and ideas. We consistently fail to grasp how many ideas remain to be discovered. Possibilities do not add up. They multiply.”

ideas and innovation increase multiplicatively (that is, exponentially) and not arithmetically (that is, linearly) in tandem with the exponential growth in population and that the process is open-ended and effectively limitless.

From a scientific perspective the truly revolutionary character of the Industrial Revolution was the dramatic change from an open system where energy is supplied externally by the sun to a closed system where energy is supplied internally by fossil fuel.

Second Law is the warming of the atmosphere due to the release of energy stored underground in fossil fuels onto the surface of the planet.

nothing comes from nothing.

A possible science of sustainability requires understanding global dynamics as a complex evolving adaptive system composed of many interlocking and interacting subsystems that are themselves complex adaptive systems, all evolving together potentially under energy, resource, and informational constraints.

We need to understand how the dynamics of innovation, technological advances, urbanization, financial markets, social networks, and population dynamics are interconnected and how their evolving interrelationships fuel growth and societal change—and, as manifestations of human endeavors...

every day by the sun to the Earth, there is no energy problem. To get a sense of the relative scales involved, consider the following: the total amount of energy delivered by the sun to the Earth is approximately a million trillion (1018) kilowatt-hours a year, compared with our “measly” needs (on this scale) of 150 trillion (1.5 × 1014) kilowatt-hours we collectively use each year. So on the scale of what the Earth receives from the sun, our energy use represents only about 0.015 percent of what is in principle actually available to us. To put it another way: more energy is delivered by the sun in just one hour than is used by the entire world in a single year.

The process of burning fossil fuels releases energy stored in chemical bonds that hold the atoms and molecules of coal, oil, or gas together. All molecules, whether they are the building blocks of your body, your brain, your house, or your computer, are held together by the forces of electromagnetism and, as such, are characterized by energies whose magnitude is in the range of electron-volts (eV), which is the unit conventionally used to measure them. An electron-volt is infinitesimal on the scale of the energies we have been considering: 1eV is equivalent to only about a three hundred trillion trillionth of a kilowatt-hour (1eV = 3 × 10-26 kWh), so in terms of these atomic units, the amount of energy we consume each year is about 5 × 1039eV.

the sun, which consists primarily of hydrogen and helium, is fueled by nuclear energy stored in the bonds that hold nuclei together. It is released as radiation when hydrogen nuclei fuse together to form helium nuclei. This is called nuclear fusion and is the fundamental physical mechanism for how the sun shines, providing us energy in the form of the light and heat that gave rise to all life on the planet. It remains the sole source of energy for all life on Earth, except for us over the past few thousand years since we discovered its power stored in fossil fuels.

networks that transport energy and resources in their bodies. Cities are sustained by similar network systems such as roads, railways, and electrical lines that transport people, energy, and resources and whose flow is therefore a manifestation of the metabolism of the city.

These flows are the physical lifeblood of all cities and, as with organisms, their structure and dynamics have tended to evolve by the continuous feedback mechanisms inherent in a selective process toward an approximate optimization by minimizing costs and time:

book, The Death and Life of Great American Cities, had an enormous influence across the globe on how we think about cities and how we approach “urban planning.”

The Death and Life of Great American Cities,

Cities have an organic quality. They evolve and physically grow out of interactions between people.

The great metropolises of the world facilitate human interaction, creating that indefinable buzz and soul that is the well-spring of its innovation and excitement and a major contributor to its resilience and success, economically and socially.

Science at its best is the search for commonalities, regularities, principles, and universalities that transcend and underlie the structure and behavior of any particular individual constituent, whether it be a quark, a galaxy, an electron, a cell, an airplane, a computer, a person, or a city.

with each doubling of population size, a city needs only about 85 percent more gas stations—and not twice as many as might naively be expected—so there is a systematic savings of about 15 percent with each doubling.

other infrastructural quantities associated with transport and supply networks, such as the total length of electrical lines, roads, water and gas lines, all scale in much the same way with approximately the same value of the exponent, namely about 0.85.

Thus the larger the city the more innovative “social capital” is created, and consequently, the more the average citizen owns, produces, and consumes, whether it’s goods, resources, or ideas.

doubling the size of a city not only increases wages, wealth, and innovation by approximately 15 percent per capita but also increases the amount of crime, pollution, and disease to the same degree.

Cities provide a natural mechanism for reaping the benefits of high social connectivity between people conceiving and solving problems in a diversity of ways. The resulting positive feedback loops act as drivers of continuous multiplicative innovation and wealth creation, leading to superlinear scaling and increasing returns to scale.

the generic geometric and dynamical properties of biological networks that underlie quarter-power allometric scaling are: (1) they are space filling (so every cell of an organism, for instance, must be serviced by the network); (2) the terminal units, such as capillaries or cells, are invariant within a given design (so, for instance, our cells and capillaries are approximately the same as those of mice and whales); and (3) the networks have evolved to be approximately optimal (so, for instance, the energy our hearts have to use to circulate blood and support our cells is minimized in order to maximize the energy available for reproduction and the rearing of offspring).

For example, our road and transport networks have to be space filling so that every local region of the city is serviced, just as all of the various utility lines have to supply water, gas, and electricity to all of its houses and buildings.

Hunter-gatherers were significantly less hierarchical, more egalitarian and community oriented than we are. The struggle and tension between unbridled individual self-enhancement and the care and concern for the less fortunate has been a major thread running throughout human history, especially over the past two hundred years.

Nevertheless, it seems that without the motive of self-interest our entrepreneurial free market economy would collapse.

infrastructural networks the flows in utility lines systematically decrease from central supply units, such as power stations and waterworks, through the pipes and electrical lines of their respective networks to supply individual houses in much the same way that blood flow in the circulatory system decreases in approximately regular geometric proportion from the heart down through the aorta to the capillaries to supply cells.

Christaller posited that urban systems, and by implication individual cities, can be represented as idealized two-dimensional crystalline geometric structures based on a highly symmetric hexagonal lattice pattern that repeats itself at smaller and smaller rescaled granularities,

Hexagons were chosen as the simplest nontrivial shape that could fit together edge to edge so as to completely fill the geographical extent of the city or urban system without gaps in between.

The city is not a top-down engineered machine dominated by straight lines and classic Euclidean geometry, but rather is much more akin to an organism with its crinkly lines and fractal-like shapes typical of a complex adaptive system—which it

fractal dimensions are a measure of an object’s degree of crinkliness, which some interpret as a measure of its complexity.

The New Science of Cities, which

number of links connecting any two people is approximately just six. Hence the phrase “six degrees of separation”—that’s it, we are separated from each other by just six links, so despite appearances we are surprisingly closely connected.

shortest path between nodes is on average a relatively small number and that this number is essentially independent of the size of the population, so that the six degrees of separation is approximately the same across all communities.

suggests that the conundrum as to why good people can do very bad things originates in peer pressure situations, fear of rejection, and a desire to be part of a group where power and control are conferred on individuals by authority.