For every action, there is an equal and opposite reaction. » Newton’s Third Law

The theory of relativity is founded on empathy. Not empathy in the ordinary emotional sense; empathy in a rigorous scientific sense. The crucial idea is to imagine how things would appear to someone who’s moving in a different way than you are.» Steven Strogatz1

In Storm in a Teacup: The Physics of Everyday Life, Helen Czerski tells the story of the Fram, a boat designed “to work with nature instead of against it.”1 In the late 1800s there was immense curiosity about the North Pole. But the ships that were sent to try to get there would get stuck in the ice of the Arctic, freezing in place. As the ice

Reciprocity can be summed up like this: when you act on things, they act on you.

The result is a system where politicians have little incentive to think beyond the current election cycle.

All living beings require energy to perform their daily functions, including sleeping. Over time, species have developed different mechanisms to increase their energy efficiency. The tendency in organisms to conserve their energy is what ensures they will have extra to draw on in times of increased need. For humans, we have to be careful though, to

two systems of different temperatures, when exposed to each other, eventually become the same temperature.

For example, although today most birds use their feathers to fly, it would be incorrect to say that this means that feathers emerged in these birds specifically for flight. In fact, feathers first emerged in dinosaurs for the purposes of insulation or attracting mates, not flight.

Most of the time, our consumption patterns are based on habit, not new thinking.