Storm in a Teacup: The Physics of Everyday Life(38)

These days, controlling the natural frequency of buildings is taken very seriously by architects. Management of shaking is even sometimes celebrated. In the Taipei 101, a 1670-foot monster in Taiwan that from 2004 to 2010 was the largest building in the world, the place to visit is the viewing galleries on the 87th–92nd floors. This section of the building is hollow, and suspended inside it is a 660-ton spherical pendulum, painted gold. It’s beautiful and weird—and practical. It’s there not just as an aesthetic quirk, but to make the building more earthquake-resistant. The technical name for it is a tuned mass damper, and the idea is that when there’s an earthquake (a common occurrence in Taiwan), the building and the sphere swing independently. When an earthquake starts, the building sways one way and pulls the spherical pendulum sideways too. But by the time the sphere has moved in that direction, the building has swayed back the other way, and is now tugging the sphere back. So the sphere is always pulling in the opposite direction to the movement of the building, reducing its sway. The sphere can move 5 feet in any direction and it reduces the overall oscillation of the whole building by about 40 percent.# The humans inside would be far more comfortable if the building never moved. But earthquakes shove the building out of equilibrium so that it has to move. The architects can’t stop that happening, but they can tweak what happens on the return journey. The occupants of the building have no choice but to sit tight as the huge tower sways past the equilibrium position and back again, until the energy is lost and serene stasis is restored.


THE PHYSICAL WORLD is always ticking along toward equilibrium. This is a fundamental physical law, known as the Second Law of Thermodynamics. But there’s nothing in the rules to say how quickly it has to get there. Every injection of energy kicks things away from equilibrium, moves the goalposts, and the winding down has to start all over again. Life itself can exist because it exploits this system, using it to shunt energy around by controlling the speed of flow toward equilibrium.

Plants still sneak into my life, even though I live in a big city. From my office, I can see bright sunlight falling on the lettuce seedlings, strawberry plants, and herbs on the balcony. The light falling on the wooden decking is absorbed by the wood, which heats up, and that heat is eventually dispersed through the air and the building. Equilibrium is reached quite quickly, but nothing very exciting happens along the way. But the sunlight that falls on those coriander leaves is entering a factory. Instead of being converted straight into heat, it’s diverted to serve the needs of photosynthesis. The plant uses the light to boot molecules out of equilibrium, and so keeps the energy for itself. By controlling the easiest path back toward equilibrium, the machinery of the plant uses that energy in stages, to make molecules that act as chemical batteries, and then uses those to convert carbon dioxide and water into sugars. It’s like a fantastically complex system of canals carrying energy, complete with lock gates, bypass sections, waterfalls, and waterwheels, and the flow of energy is controlled by changing the speed at which it passes through each section. Instead of streaming straight to the bottom, the energy is forced to build complex molecules on the way. These aren’t in equilibrium, but the plant can store them until it needs their energy, and then it places them somewhere where they can take the next step down toward equilibrium, and then the next step after that. As long as light is falling on to that coriander plant, it’s supplying the energy to keep the factory on the hop, continually chasing after equilibrium as the injection of energy moves the goalposts. Eventually, I’ll eat the coriander, and that will provide an injection of energy to my system. I’ll use that energy to keep my own body from equilibrium, and as long as I keep eating, the system won’t be able to keep up. Equilibrium won’t be reached. But I choose when to eat, and my body chooses when to use that energy, all by controlling the floodgates.

Considering how common life is on this planet, it’s surprising that no one can come up with a single definition of what it is. We know it when we see it, but the living world can usually provide an exception to any simple rule. One definition has to do with maintaining a non-equilibrium situation, and using that situation to build complex molecular factories that can reproduce themselves and evolve. Life is something that can control the speed at which energy flows through its system, manipulating the stream to maintain itself. Nothing that is in equilibrium can be alive. And this means that the concept of disequilibrium is fundamental to two of the great mysteries of our time. How did life start? And is there life anywhere else in the universe?

Scientists currently think that life may have started in deep-sea vents, 3.7 billion years ago. Inside the vents was warm alkaline water. Outside was cooler, slightly acid ocean water. As they mixed, at the surface of the vent, equilibrium was reached. It seems that early life may have started by standing in the middle of that path to equilibrium, and acting as a gatekeeper. The flow toward equilibrium was diverted to build the first biological molecules. That first tollgate may then have evolved into a cell membrane, the city wall around each cell that separates inside, where there is life, from outside, where there isn’t. The first cell was successful because it could hold back equilibrium, and that was the gateway to the beautiful complexity of our living world. The same is probably true for other worlds.

It seems highly likely that life does exist elsewhere in the universe. There are so many stars, with so many planets, and so many different conditions, that however freaky the conditions needed to form life are, they will have happened in other places. But the chances of that life telling us that it’s there by sending us a radio signal are small. Quite apart from anything else, space is so large that by the time any signal reaches us, the civilization that created it would probably be long extinct. However, it may be that the mere existence of life could be broadcasting signals out into the cosmos, completely unintentionally. On the summit of Mauna Kea in Hawaii there is a pair of telescope domes, matching giant white spheres parked next to each other on a ridge. My first thought when I saw them was that they were like giant frog’s eyes peering out into the cosmos. This is the Keck Observatory, and it may be these giant eyeballs that see the first hints of life outside our solar system. As alien worlds pass across the front of the distant stars that they orbit, starlight shines through the atmosphere, and those gases leave a fingerprint on the light. The Keck telescopes are starting to pick up those fingerprints, and soon they may be able to detect atmospheres that are not in equilibrium. Too much oxygen to be sustainable, too much methane . . . these could betray the existence of life down on the planet, altering the balance of its world as it strains away from the jaws of equilibrium. We may never know for certain. But that may be the closest we ever come to knowing that there are other organisms out there: the evidence of something controlling the speed of the march to equilibrium, as it builds living complexities that we will never see.