Making comparison and distinctions

In the following paragraph, Brian Greene does not state that his intention is to compare Newton and Einstein. His use of parallel sentences make the comparison clear all the same.

In Newton’s theory, gravity arises solely from an object’s mass. The bigger the mass, the bigger the object’s gravitational pull. In Einstein’s theory, gravity arises from an object’s mass (and energy) but also from its pressure. Weigh a sealed bag of potato chips. Weigh it again, but this time squeeze the bag so that the air inside is under higher pressure. According to Newton, the weight will be the same, because there’s no change in mass. According to Einstein, the squeezed bag will weigh slightly more, because although the mass is the same there’s been an increase in pressure. In everyday circumstances we’re not aware of it, because for ordinary objects the effect is fantastically tiny. Even so, general relativity, and the experiments that have shown it to be correct, makes it perfectly clear that pressure contributes to gravity.

(Greene, 2011, p.53)

Conveying distinctions in the natural world is not always an easy task. Getting a distinction across in an entertaining way comes from a real desire to communicate:

Two of the most familiar members of the thrush family are robins and bluebirds, and those two species are readily distinguishable from one another. But there are also several species of “spotted-breasted” thrushes, and they can be tricky to identify. All of these birds are brown on the back with various amounts of spotting in the front; this includes the aforementioned Hermit Thrush. But when it comes to identifying this particular thrush, there is one piece of information that is very helpful to know…the date. All of our other spotted thrushes leave North America for the winter, but like the Pine Warblers we discussed last week, Hermit Thrushes are short-distance migrants. They are quite happy to spend the non-breeding season in the Southern states, with a few hardy souls riding it out here on Cape Cod. Therefore, if you see a thrush in your Sandwich birdbath in January, you don’t even have to look in your bird book, just write down Hermit Thrush. It’s that easy. You can worry about identifying all of the other spotted thrushes in the summer, which is coming up, if our officials don’t cancel that, too.

(O'Connor, 2020)

Note: The choice of these two authors was inspired by talks given a few years ago by Professor Steven Pinker in connection with the release of his book, The sense of style. The talks can be seen on Youtube. If you wish to borrow the book from the university library, the full reference is:

Pinker, S. (2015). The sense of style: The thinking person's guide to writing in the 21st century. Penguin.