by James Morris
For George Buckley, who first introduced me to the word Syzygy.
Now there’s a word you don’t hear everyday. Apart from its usefulness in Scrabble and perhaps crossword puzzles, you might wonder what else it’s good for, or even what it means.
It turns out that “syzygy” is used in many different fields. In astronomy, it describes three planets lined up in a row. This occurs, for example, during solar and lunar eclipses, when the sun, Earth, and moon are all aligned. In biology, it describes pairing of chromosomes that occurs, for example, in a specialized type of cell division called meiosis that produces gametes (eggs and sperm).
The term also describes two closely paired joints in the arm of a crinoid, which is a marine organism more commonly known as a sea lily. Evidently, “Syzygy” is also the name of a Japanese band and an episode of The X-files, according to Wikipedia. And it has other meanings in fields as diverse as poetry and mathematics.
I’ve been a biologist for over 20 years, and I’ve never heard the term before. I guess I don’t know that much about crinoids, and I have always called the pairing of chromosomes, well, pairing. Sometimes synapsis, usually pairing, never syzygy.
But I think this is why some students struggle with science. Everyone tells you that science is a way to understand the world. No one tells you that it’s also a language, with its own vocabulary and style of writing. But it is. Other than quantum mechanics, relativity, and string theory, there are really not a lot of difficult concepts in science. It’s just that there are so many unfamiliar terms, like syzygy, describing unfamiliar things, like chromosomes or crinoids.
No wonder it’s so difficult.
In teaching, I often find that if you break down these words, you can find clues to their meanings. Take photosynthesis. This is the process that occurs in plants, algae, and certain bacteria in which the energy of sunlight is used to build sugars. The meaning of the term photosynthesis, then, is right there in front of you – “photo” for light and “synthesis” for build.
But there are terms for which this trick doesn’t work so well. “Syzygy,” in Greek, evidently means “union” or “pair” or “coupling,” but most people don’t know Greek, so that’s not very helpful.
Sometimes, definitions don’t even help that much. Alan Alda, well known as the actor who played Hawkeye Pierce in the television series M*A*S*H, tells the story of how, at age 11, he asked his science teacher what a flame is. After some thought, the teacher replied, “combustion.” As Alda explains, this was simply replacing one term he didn’t understand with another.
Sometimes we use analogies to make complicated words or processes simpler. Mitochondria, which are structures within cells involved in energy metabolism, are often called the “powerhouse” of the cell. ATP, which is the form of energy that cells use for everyday tasks, is often referred to as the “currency” of the cell. And DNA, the genetic material that stores, encodes, and transmits information, is sometimes called the “blueprint” of life.
These are useful, but only somewhat. Today’s students might ask – “What’s a blueprint?” And some students don’t realize that currency is money, or what this has to do with ATP. The mitochondria-as-powerhouse analogy is so overused that we start to forget what it means.
What makes some words in science even more difficult is that the same word can have different meanings. Take the term “fixed.” In genetics, a form of a gene (allele) or a trait is fixed when everyone in the population has it. In cell biology, you fix or preserve a cell for microscopy. And in chemistry, a molecule is fixed when it becomes biologically available. Nitrogen in the air is plentiful, for example, but it cannot be used by most organisms. It has to be fixed – converted to some other molecule, like ammonia – to be available to plants and animals.
What’s particularly confusing is that these definitions have nothing to do with the two common, everyday meanings of the word – either unchanging (“He is fixed in his views”) or repaired (“The car is fixed”).
Differences between scientific and everyday definitions have led to all manner of difficulty and misunderstanding. A well-known example is the word “theory.” To a scientist, a theory is as good as it gets. It’s a well-tested set of explanations that can explain a diverse set of phenomena. It’s essentially what the rest of the world calls a fact. But, in everyday usage, a theory sounds tentative, like a hunch or guess.
This difference of meaning is played out in debates about evolution – “It’s only a theory” can be taken in different ways, depending on your particular views. The phrase sounds negative if you go with the everyday definition – after all, it’s only a theory – or it’s comforting, knowing that evolution is in the same company as gravity, germs, and, yes, chromosomes.
When terms are problematic, scientists sometimes try to find better ones to convey their meaning. Consider “natural selection.” Darwin introduces the phrase in his classic work, On the Origin of Species. In fact, he places it right in the title, which continues, by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life.
But Darwin had reservations about the phrase. Perhaps it sounded too much like nature is a conscious agent doing the selecting, which is not what Darwin intended. In a letter to geologist and friend Charles Lyell, Darwin suggested the term “natural preservation” as better conveying what he meant.
The philosopher Herbert Spencer coined the phrase “survival of the fittest” as another alternative to “natural selection.” At first, Darwin was reluctant to use that phrase. However, he eventually agreed, and it first appears in the fifth edition of the Origin, published in 1869, ten years after the first edition.
But, as many have noted, the phrase may not be quite right to explain Darwin’s theory. It’s not survival that’s key – it’s reproduction. And “fittest”, like “fixed” and “theory”, has different meanings in everyday use and in biology. To many, fittest is what happens when you spend lots of time working out in a gym: it means strongest or biggest. But, to a biologist, it has nothing to do with being physically fit; instead it refers to reproductive success. There are other problems with the phrase, which is why most scientists shy away from using it.
Science, after all, is about being precise, so it requires terms and vocabulary that accurately describe what’s out there. This is why there are so many terms in science. Like any language, these words become easier with practice, lots of practice. But when you start to use them, you begin to notice eloquence in scientific language. At the same time, scientists need to learn to be better interpreters, so that the language of science is translated into everyday language in clear and meaningful ways.
Perhaps what’s required is a closer pairing of scientists and the public. A syzygy, if you will.
© James Morris and Science Whys, 2014.