The annoying thing about hammocks is that they obey the second law of thermodynamics. However big an initial shove you give them, they always come to a standstill. The swing’s energy is dissipated through air resistance and friction in the ropes.
That’s irritating if, like me, you enjoy a nap in a gently rocking hammock. But it’s also instructive: the hammock is a perfect metaphor for the second law.
The law says that a system will naturally move to its lowest free energy state. You already know this from the hammock: it comes to rest when all the energy available to keep it moving has been used up. If there were energy left, it would still be swinging.
Since this law is the way the universe goes, it is helpful to try to design with it rather than against it.
Three modes of design from the second law of thermodynamics
1 – Design for resting equilibrium — no energy cost
- Design the system’s natural resting state so that it is also the useful one.
- For example, put the pond at the bottom of the hill so that it fills itself.
2 – Intercept the flows — medium energy cost
- Catch free energy while it’s on the move. This takes some organisational effort but can be minimal.
- For example, run the water through a turbine on its way downhill to the pond. The water is heading that way anyway, so can we use it?
3 – Fight the flow — high energy cost
- Push the system in the opposite direction of free energy dispersal. This takes work to create and maintain, creating fragility.
- For example, pumping the water uphill, and storing it there for later use.
The further down this list we go, the more energy we need.
Life as the free energy interceptor
In the living world, physical processes, powered by the sun, the motion of the planet and moon, and heat from the earth, put the work into raise the energy level of the systems that surround us: evaporating water to create rain, driving tides in and out of our shores, heating the air to drive winds and raining radiation on the Earth’s surface.
Life intercepts this free energy on its way down hill; on its journey from concentrated to spread out. This is the principle upon which whole cascade of life depend, from the processes driven by ion imbalances across cell membranes, to the multitude of species supported on a wooded slope as the intercepted water slowly makes its way downhill.
Where is regenerative design in all of this?
The goal of regenerative design for is for humans and the living world to survive, thrive and co-evolve. The living world thrives by catching energy as flows downhill, cycling it through a multitude of interlocking systems and lifeforms. To co-evolve and thrive we need to get involved with this dance. Rather than burning energy to fight the flow, we should be looking for where we can lean into, and even strengthen this life-giving process of harnessing these energy gradients.
Where to hang the hammock
All of that thus resolved, the only remaining question is where to hang the hammock.
I would say, halfway down the hill, where the sound of the waterfall would send me to sleep. And I could dream about creating an ingenious mechanism for rocking the hammock powered by the falling water.
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This post was inspired in part by a working diagram Chris Wise showed me how should be designing for equilibrium. I’ll share more when Chris publishes it. And also by lectures on thermodynamics from Peter Atkins, many lunar cycles ago.