Here are a few sentences that help to create an everyday image for the speed of the F-22:
At top speed, the F-22 Raptor would circle the Earth in sixteen-and-a-half hours. For perspective, if the Raptor took off on the same journey at the same time as a Boeing 737, the Raptor pilot could land, get a full night’s sleep, and spend another entire 24 hours waiting for the passenger jet to finally arrive. Compared to fighter planes of earlier eras, like the 1934 Boeing Stearman 75, the Raptor would make the flight and then collect a week’s worth of dust in the hangar before the older plane finally arrived.
Numbers like 2,414 km/h are very difficult to conceptualize without adding context to help your audience. Using comparative calculations, especially ones that make use of easily visualized benchmarks will help your audience to appreciate these difficult to comprehend figures.
Here are a couple example sentences without and then with their comparative benchmarks for comparison:
“The world’s largest tree, the giant sequoia General Sherman, is estimated to weigh an incredible 2 million kilograms.”
Now, the same sentence with a benchmark for comparison:
“The world’s largest tree, the giant sequoia General Sherman, is estimated to weigh an incredible 2 million kilograms, roughly the equivalent of sixty fully-loaded cement trucks.”
Here’s a different example:
“The thickest of the ultra-thin second-generation solar cells are about 10μm thick.”
Now, the same sentence with a benchmark:
“The thickest of the ultra-thin second-generation solar cells are about 10μm thick, which is about as thin as a single sheet of plastic wrap.”
In addition to difficult numbers, there are other description points that can benefit from visual imagery to help an audience to understand abstract or complex ideas easily. Complex processes are very common areas of confusion for an audience, often because writers often struggle to convey complex processes clearly. Fortunately, there’s a helpful tool that you can use to describe complex processes. The simile or metaphor.
As a writer, you can think of metaphor as a cognitive tool—a shortcut from one concept or situation the reader already understands to a new, similar idea you’re trying to help them learn. And just like with benchmarks, metaphors that help your audience form a visual image of the process you’re explaining are going to be extra powerful.
First, though, I’m going to explain how a solar cell works, and I’m going to do it without the aid of any metaphors. We’ll see how well that works:
A solar cell is made by adding impurities to silicon, usually (negatively charged) phosphorous and (positively charged) boron. Placing this collection of atomic elements tightly into an electric field places these atoms in an orientation that is prone to releasing electrons. Then, when this electrical field is exposed to sunlight, the energy of the photons causes electrons to be released. These electrons are then channeled into electrical wires that transport the electricity to the electrical grid.
That’s not a terrible explanation of a complex process. But it also doesn’t necessarily create a clear picture of this process in the audience’s mind. Now, I’m going to use metaphor to generate a clearer picture of the process:
A solar cell is made by adding impurities to silicon, usually (negatively charged) phosphorous and (positively charged) boron. Packing this collection of atomic elements tightly into an electric field places these atoms in an orientation that is prone to shedding electrons. It’s a bit like racking together a cluster of atomic billiard balls. Then, when this cluster gets exposed to sunlight, the light photons act like the cue ball, knocking electrons free. These freed electrons are then channeled into electrical wires that transport the electricity to the electrical grid.
The obvious metaphor in this second version uses a visual image most people will find familiar, the cue ball knocking another ball loose from a cluster of subatomic particles. Of course, as with all metaphors, it isn’t exactly analogous to what happens when photons strike a solar cell, but it’s close enough to convey the idea in a clear manner that helps the reader to better understand the process.
And that’s actually not the only metaphor in that updated explanation. Metaphors don’t always have to be as long and drawn out as the cue-ball analogy. In fact, most metaphors are embedded in words we commonly use, so much so, that lots of the metaphors we commonly use go unnoticed. Did you catch that second metaphor? It comes at the end of this sentence:
“Packing this collection of atomic elements tightly into an electric field places these atoms in an orientation that is prone to shedding electrons.”
“Shedding electrons” is a single-word metaphor that implies that these atoms releasing electrons is as natural as a dog getting rid of its winter coat, and it only takes one word to set-up that implication.
Here’s a much more overt one-word metaphor that also generates an image to help explain how sunflower plants can be used to clean up toxic soil:
The key to the soil cleanup capacity of sunflowers is their need to pull water and nutrients from the ground. Just as humans and other animals need to eat enough calcium, potassium and other essential elements and molecules to keep their biological systems running smoothly, plants also need the same sorts of materials to make the proteins, enzymes, and other cell components they need for survival. Surprisingly, though, plants will take up the ions of toxic heavy metals too—even radioactive ions that have no known biological function for the plants. This occurs because the “gatekeepers” of the root membranes of some plants aren’t very picky and will let most metal ions through as long as they have the right charge.
In this case, the word “gatekeeper” denotes one of the functions of the root membranes—to sort which molecules stay outside in the soil, and which molecules the root membranes allow into the plant. One could conjure the image of a bouncer who lets everyone into the club as long as they have the right charge, and ID, of course.
So you can see in these last two cases, metaphors don’t have to be drawn out to help convey a clear picture of a complex process.
All three of these techniques, comparative calculations, benchmarks, and descriptive metaphors are effective tools in your writer’s toolbox. And they’re particularly effective at clearly conveying difficult, abstract, or complex information in an accessible and memorable way. Using these tools as description points in places where your audience may struggle to grasp a difficult concept will help you to connect with your reader.
Now that you know what they are, look for these description points in your favorite science writing. You’ll see these three techniques at work in the articles and presentations of the best science writers all the time. And now that you know what these writers are doing, and how easy it is to learn to apply these skills at description points, you too can communicate difficult concepts vividly and easily in your own writing.