While social media attention is potentially an instrument to achieve ends like elite celebrity, some content creators desire ordinary fame as a social end in itself. Not unlike reality television stars, social media celebrities are often criticized for not having skills and talents associated with traditional, elite celebrity, such as acting or singing ability. This criticism highlights the fact that digital content creators face real barriers to crossing over to the sphere of elite celebrity. However, the criticism also misses the point that the phenomenon of ordinary celebrity reconstructs the meaning of fame. The elite celebrity is symbolized by the metaphor of the star, characterized by mystery and hierarchical distance and associated with naturalized qualities of talent and class. The ordinary celebrity attracts attention through regular and frequent interactions with other ordinary people. Achieving ordinary fame as a social media celebrity is like doing well at a game, because in this sphere, fame is nothing more nor less than relatively high scores on attention scales, the metrics of subscribers, followers, Likes, or clicks built into social media applications.

Why do we have the illusion that cramming for an exam is the best learning strategy? Because we are unable to differentiate between the various sections of our memory. Immediately after reading our textbook or our class notes, information is fully present in our mind. It sits in our conscious working memory, in an active form. We feel as if we know it, because it is present in our short-term storage space ... but this short-term section has nothing to do with the long-term memory that we will need in order to recall the same information a few days later. After a few seconds or minutes, working memory already starts disappearing, and after a few days, the effect becomes enormous: unless you retest your knowledge, memory vanishes. To get information into long-term memory, it is essential to study the material, then test yourself, rather than spend all your time studying.

Biologists distinguish two kinds of similarity. "Analogous" traits are ones that have a common function but arose on different branches of the evolutionary tree and are in an important sense not "the same" organ. The wings of birds and the wings of bees are both used for flight and are similar in some ways because anything used for flight has to be built in those ways, but they arose independently in evolution and have nothing in common beyond their use in flight. "Homologous" traits, in contrast, may or may not have a common function, but they descended from a common ancestor and hence have some common structure that indicates their being "the same" organ. The wing of a bat and the front leg of a horse have very different functions, but they are all modifications of the forelimb of the ancestor of all mammals. As a result, they share nonfunctional traits like the number of bones and the ways they are connected. To distinguish analogy from homology, biologists usually look at the overall architecture of the organs and focus on their most useless properties.

Seawater contains an abundance of dissolved oxygen that all marine animals breathe to stay alive. It has long been established in physics that cold water holds more dissolved oxygen than warm water does ― this is one reason that cold polar seas are full of life while tropical oceans are blue, clear, and relatively poorly populated with living creatures. Thus, as global warming raises the temperature of marine waters, it is self-evident that the amount of dissolved oxygen will decrease. This is a worrisome and potentially disastrous consequence if allowed to continue to an ecosystem-threatening level. Now scientists have analyzed data indicating that the amount of dissolved oxygen in the oceans has been declining for more than a half century. The data show that the ocean oxygen level has been falling more rapidly than the corresponding rise in water temperature. Falling oxygen levels in water have the potential to impact the habitat of marine organisms worldwide and in recent years this has led to more frequent anoxic events that killed or displaced populations of fish, crabs, and many other organisms.

Capuchins ― New World Monkeys that live in large social groups ― will, in captivity, trade with people all day long, especially if food is involved. I give you this rock and you give me a treat to eat. If you put two monkeys in cages next to each other, and offer them both slices of cucumber for the rocks they already have, they will happily eat the cucumbers. If, however, you give one monkey grapes instead ― grapes being universally preferred to cucumbers ― the monkey that is still receiving cucumbers will begin to throw them back at the experimenter. Even though she is still getting "paid" the same amount for her effort of sourcing rocks, and so her particular situation has not changed, the comparison to another makes the situation unfair. Furthermore, she is now willing to abandon all gains ― the cucumbers themselves ― to communicate her displeasure to the experimenter.