On our little world, light travels, for all practical purposes, instantaneously. If a lightbulb is glowing, then of course it's physically where we see it, shining away. We reach out our hand and touch it: It's there all right, and unpleasantly hot. If the filament fails, then the light goes out. We don't see it in the same place, glowing, illuminating the room years after the bulb breaks and it's removed from its socket. The very notion seems nonsensical. But if we're far enough away, an entire sun can go out and we'll continue to see it shining brightly; we won't learn of its death, it may be, for ages to come ― in fact, for how long it takes light, which travels fast but not infinitely fast, to cross the intervening vastness. The immense distances to the stars and the galaxies mean that we see everything in space in the past.

Financial markets do more than take capital from the rich and lend it to everyone else. They enable each of us to smooth consumption over our lifetimes, which is a fancy way of saying that we don't have to spend income at the same time we earn it. Shakespeare may have admonished us to be neither borrowers nor lenders; the fact is that most of us will be both at some point. If we lived in an agrarian society, we would have to eat our crops reasonably soon after the harvest or find some way to store them. Financial markets are a more sophisticated way of managing the harvest. We can spend income now that we have not yet earned ―as by borrowing for college or a home ―or we can earn income now and spend it later, as by saving for retirement. The important point is that earning income has been divorced from spending it, allowing us much more flexibility in life.

Many things spark envy : ownership, status, health, youth, talent, popularity, beauty. It is often confused with jealousy because the physical reactions are identical. The difference: the subject of envy is a thing (status, money, health etc.). The subject of jealousy is the behaviour of a third person. Envy needs two people. Jealousy, on the other hand, requires three: Peter is jealous of Sam because the beautiful girl next door rings him instead. Paradoxically, with envy we direct resentments toward those who are most similar to us in age, career and residence. We don't envy businesspeople from the century before last. We don't envy millionaires on the other side of the globe. As a writer, I don't envy musicians, managers or dentists, but other writers. As a CEO you envy other, bigger CEOs. As a supermodel you envy more successful supermodels. Aristotle knew this: ‘Potters envy potters.'

A computational algorithm that takes input data and generates some output from it doesn't really embody any notion of meaning. Certainly, such a computation does not generally have as its purpose its own survival and well-being. It does not, in general, assign value to the inputs. Compare, for example, a computer algorithm with the waggle dance of the honeybee, by which means a foraging bee conveys to others in the hive information about the source of food (such as nectar) it has located. The "dance" ― a series of stylized movements on the comb ― shows the bees how far away the food is and in which direction. But this input does not simply program other bees to go out and look for it. Rather, they evaluate this information, comparing it with their own knowledge of the surroundings. Some bees might not bother to make the journey, considering it not worthwhile. The input, such as it is, is processed in the light of the organism's own internal states and history; there is nothing prescriptive about its effects.