Have you noticed the light changing?

March 25, 2021

Life moves faster in spring than at any other time of the year. We can feel it. We can measure it. 

When my daughter Madison was 5, we did a terrific experiment that I recommend to just about everyone with young kids: In the very early spring, we found a tulip that had just poked its tip out of the ground. Every day, we measured it with a ruler and plotted the results on a simple graph like the one to the right, showing the day number on the X axis and the height of the tulip on the Y axis. We also showed on the graph the days that it was rainy or sunny. You can do this with any kind of plant or flower, but tulips are especially gratifying because they grow fast, they grow tall, and they're satisfyingly showy at the end.

What did Madison learn from this experiment? That the world changes, that sometimes change is fast and sometimes it's slow, and that there are reasons for it that she can understand. She also learned that numbers and graphs are our friends: They're tools that make what had been invisible and mysterious suddenly visible and clear. She saw that the rate of change can itself change—which primed her perfectly for grasping calculus a decade later. And she had a beautiful and personal and mathematical experience of the miracle of spring.

Have you noticed the light changing? Here in the Northern Hemisphere, the amount of light in our day increases faster around the spring equinox than at any other time of year as the sun rises earlier in the morning and sets later in the evening. We also get more light during the day as it progressively arcs higher in the sky.

The metaphorical light in our lives is increasing even faster than the sunlight these days, and that's measurable, too. As more of us get vaccinated, as we see those graphs of Covid incidence taper down, more of our world is suddenly visible and accessible to us again. This miracle, though, wasn't generated by the awesome and cyclical power of Nature, but by the perhaps-even-more-awesome force of human ingenuity and determination.

Spring always brings hope. I can feel it, I can measure it...this year, more than ever.

—Deb