Things Not Seen: Reflections on Life and Science in the Pandemic
In the first summer of the pandemic, I was only able to take my kids to the beach the week before school. While the older two rode boogie boards, my younger daughter dug holes near the waterline, afraid of the waves farther out. I kept her company there, making footprints in the sand around her.
On the smooth wet sand near the edge, a footprint lasts about one wave. After that, all that remains is a subtle water-filled depression. In other situations, a footprint can last much longer. Paleontologists have found fossilized tracks from many animals including dinosaurs and ancient mammals. Our local museum even has one from a Paleozoic spider. Each such track is a small miracle of geological circumstance. An animal must walk on an impressionable surface. Then that surface must lie undisturbed long enough to harden and be covered over by new layers of sediment. Finally, millions of years later, it must erode out and be found by someone. The scientific interest in these imprints is not so much the tracks themselves, as what they reveal about things we can’t see directly — about how an animal moved, how it made a living, how it died.
In the pandemic, there are many things unseen. The major outbreaks in China, Europe and the United States became established following undetected community transmission. The virus was present and passing from person to person before public health officials recognized what was happening. Individual cases also frequently have aspects unobserved. Some infected people are asymptomatic and never know they have it. Others know they have it all too well, but are condemned to suffer in isolation, out of the sight of others.
From my apartment every morning I hear horns from the nearby commuter rail, sounds which remind me of the last time I lived alone in an apartment. That was a different city and many years ago. But somehow the similarity of sound and circumstance is not lost on the deep parts of my brain. Memories are really just connections. Each of our neurons communicates with many others, and when a new memory forms it involves adjustments to the strength of these connections. Our entire selves are embedded in this cryptic network, including what we feel, and what we know about the past. Things can easily lie buried there, like a plastic toy under the sand.
Sometimes, a sound, a gesture or a glint of something can unlock these hidden things. My mom has a story about a woman whose young son died years ago. Months later, she found the boy’s fingerprints still on a window, triggering a flood of memory and grief.
Science, of course, is also about unlocking hidden things. The coronavirus is thought to have jumped into humans from another species, an event which explains the absence of preexisting immunity in the human population. This cross-species transfer was not directly observed by anyone. We know it happened based on comparisons with the genome of other coronaviruses.
Sometimes, the evidence for such inferences is concrete, like fossils or the beautiful hand stencils archaeologists have found in prehistoric caves. In other cases, it is much more subtle. In the 1960s early radio astronomers were plagued by what seemed to be noise in their telescope. It persisted no matter what they did or which way they pointed the instrument. Later referred to as the cosmic microwave background, this noise turned out to be leftovers from the big bang. We now study it to learn about the universe in its infancy.
Divining such truths is not easy. Some things can only be seen at the right angle, in the right light. Like a fingerprint on a window, or a child’s feelings during a divorce.
One of the more lyrical passages in the Bible says, “faith is the assurance of things hoped for, the conviction of things not seen.” While science is a discipline built on observation and logic, it also requires faith. The cosmic microwave background arose when the universe had cooled enough to become transparent. It thus represents the first light, coming to us from almost 14 billion years in the past. Because detecting it requires expertise of many kinds, a researcher studying this phenomenon must rely on others with different skills and knowledge. The same is true for the study of fossil trackways or the pandemic coronavirus. All these depend on faith in people and institutions, faith in each other.
While afraid of the waves, my younger daughter was also drawn to them. For a time, we played paddle ball and explored nearby tide pools. But at some point, we ended up back in the water, this time farther out, clinging to each other as the waves broke past us.
