Lab Girl

by Hope Jahren

Science has taught me that everything is more complicated than we first assume, and that being able to derive happiness from discovery is a recipe for a beautiful life. It has also convinced me that carefully writing everything down is the only real defense we have against forgetting something important that once was and is no more, including the spruce tree that should have outlived me but did not.

Each beginning is the end of a waiting. We are each given exactly one chance to be. Each of us is both impossible and inevitable. Every replete tree was first a seed that waited.

The leaves of the world comprise countless billion elaborations of a single, simple machine designed for one job only—a job upon which hinges humankind. Leaves make sugar. Plants are the only things in the universe that can make sugar out of nonliving inorganic matter. All the sugar that you have ever eaten was first made within a leaf. Without a constant supply of glucose to your brain, you will die. Period. Under duress, your liver can make glucose out of protein or fat—but that protein or fat was originally constructed from a plant sugar within some other animal. It’s inescapable: at this very moment, within the synapses of your brain, leaves are fueling thoughts of leaves.

One new idea allowed the plant to see a new world and draw sweetness out of a whole new sky.

But how to see the shape of these tiny crystals? After an ocean wave hits a lighthouse, a ripple bounces back across the ocean. The size and shape of this reflective ripple carry information about both the wave and the lighthouse. If we are anchored in a rowboat far away, we can distinguish a lighthouse with a square base from one that is rounded by the way the ripple hits us, provided that we have a very good idea of the size of the wave, its energy and timing, and the direction it has traveled. This is similar to how we work out the tiny shapes within mineral powder, using the ripples that bounce back, or diffract, from very small electromagnetic waves known as x-rays. A piece of film catches the ripples at their peaks, and their spacing and intensity allow us to reconstruct the shape off which they bounced.