The Habits of Light: A Celebration of Pioneering Astronomer Henrietta Leavitt, Whose Calculations Proved That the Universe Is Expanding
By Maria Popova
“Nothing is fixed. All is in flux,” physicist Alan Lightman wrote in his soaring meditation on how to live with our longing for absolutes in a relative universe, reminding us that all the physical evidence gleaned through millennia of scientific inquiry indicates the inherent inconstancy of the cosmos.
This awareness, so unnerving against the backdrop of our irrepressible yearning for constancy and permanence, was first unlatched when the ancients began suspecting that the Earth, rather than being the static center of the heavens it was long thought to be, is in motion, right beneath our feet. But it took millennia for the most disorienting evidence of inconstancy to dawn — the discovery that the universe itself is in flux, constantly expanding, growing thinner and thinner as stars grow farther and farther apart. In 1929, the astronomer Edwin Hubble built on the work of other scientists and formalized this in what is now known as Hubble’s Law — the first observational evidence for the ongoing expansion of the universe, which in turn furnished foundational evidence for the Big Bang model: If the universe is constantly expanding, to trace it backward along the arrow of time is to imagine it smaller and smaller, all the way down to the seeming nothingness that banged into the somethingness within which everything exists.
At the mathematical center of Hubble’s Law were the calculations of Henrietta Swan Leavitt (July 4, 1868–December 12, 1921) — one of the unheralded women astronomers, known as “the Harvard Computers,” who shaped our understanding of the universe long before they could vote. Leavitt’s particular work at the Harvard College Observatory was deemed so valuable that she was paid 20% more than the standard salary of the other computers: 25 cents per hour.
At the inaugural edition of The Universe in Verse, artist Ann Hamilton brought Leavitt’s legacy to life in her lovely reading of the “The Habits of Light” from Aperture (public library) — a collection of poems by Anna Leahy, celebrating science and many of its unsung heroines. In her wonderful prefatory meditation, Hamilton builds on her animating ethos of not-knowing as a creative act to consider the common impulse driving poetry and science, and the vital role of embracing the unknown as we regard the universe within and without — please enjoy:
THE HABITS OF LIGHT
by Anna Leahy
After Henrietta Leavitt, astronomer
The difference between luminosity and brightness
is the difference between being
and being perceived, between the energy emitted
and the apparent magnitude. O, to be
significant! To have some scope and scale!
Size and heat. Why not make that obvious,
ostensible, stretch it out for all the world to see?
Distance makes a world of difference.
The universe is made of distance and of dust.
More dust than star out there,
more crimson than cobalt from here, looking,
our eyes telling the truth slant
through the almost-nothing
of the universe’s finely grained mattering.
The Universe in Verse — a celebration of science through poetry — returns in April of 2018. For more highlights from the 2017 edition, hear Amanda Palmer’s reading of Neil Gaiman’s feminist poem about science, Janna Levin’s reading of Adrienne Rich’s tribute to women in astronomy, Tracy K. Smith’s ode to the Hubble Space Telescope, Rosanne Cash’s reading of Adrienne Rich’s homage to Marie Curie, Diane Ackerman’s poem about our search for extraterrestrial life, playwright Sarah Jones’s chorus-of-humanity tribute to Jane Goodall, Iron & Wine’s reading of Edna St. Vincent Millay’s ode to Euclid, and my reading of Wisława Szymborska’s ode to the number pi, then watch the complete show for a two-hour poetic serenade to science.
Published April 3, 2018