For the last 15 months we’ve all learned much more science than most of us ever wanted to know – from microbiology (messenger RNA) to epidemiology (herd immunity) to aerodynamics (how far does your spit fly when you chat at a cocktail party?). I am grateful for the way scientists brought their knowledge to bear to meet the challenge of COVID-19. But I am also intimidated by them. How did people get so smart? How did they figure out what experiments to run, with what variables, involving what substances, to achieve what they did?

The May 10 New Yorker has an astonishing article, “Growing it Back,” about developmental biologist Michael Levin, who has been investigating how cells grow into living beings. Levin does not see us as products of a DNA blueprint akin to what a carpenter follows in building a house, but more as the end result of a process in which cells react to their environment and to each other in deciding what to become, as if by intent. By manipulating electrical fields, the environment in which the cells operate, Levin has induced them to redirect the process of growth. He has “coaxed frogs to regenerate severed legs, and tadpoles to grow new eyeballs on their stomach.” His work may lead to therapies for amputees to grow severed limbs back. It may also lead to cancer treatments in which the cells are restored to communication with other cells rather than reproducing uncontrollably.

Levin’s work is all the more impressive to me because it seems to rely principally on close observation and manipulation of small elements of the physical environment. The physical world has seemed alien territory to me. I remember when my former graduate school girlfriend (it was just a phase!) met my late partner, Peter a few months after I started dating him. Sabra warned: “I hope you’re not expecting Mark to help with anything practical. Don’t let him do anything involving a hammer.”

Now, late in life, I’ve become immersed in my physical environment and consumed with trying to manipulate it. On this farm there is no on-premises “super” (as we denizens of New York apartments call our building superintendents) to call when things go wrong. Economic necessity and practical reality dictate that when problems arise I at least have to try to understand what’s going on and address them myself.

Given the low competence level from which I start I am often dependent, the way all physical scientists are, on the knowledge developed by those who have come before me. Thank God for the internet. This winter, trying to battle an incursion of now thankfully banished rats in the chicken coop, I learned online how to fix an empty can on a stick and suspend it over a deep bucket, place a ramp to the top of the bucket, and bait the top of the can with peanut butter. When the rat jumped over to the can, the can would spin, the rat would drop into the water at the bottom of the bucket, and drown. I remember my elation the first morning when I found half a dozen drowned rats, and my disappointment days later when I realized mine was not the only intelligence at work. The rats learned to steer clear.

I don’t rely entirely on the internet. Sometimes I run unwitting experiments. Take my tomato starts. This year I decided to see what would happen if I did not buy new seeds , but used the large supply I had left over from prior years. I planted all my usual varieties. The black krims, rose de berne, Amish paste, and sungold went into three trays in which the planting compartments were about two inches deep. Because I didn’t have a similar fourth one handy, the Brandywines went into a tray with smaller compartments about half that depth. I put them all on the same grow light shelf.

All except the Brandywines sprouted within about a week. I decided the Brandywine seeds were probably too old. I discarded that hypothesis when they eventually sprouted. But still, the Brandywines seemed stunted. The ot