i·so·chor, i·so·chore (ī′sō kôr′, -sə-) n. [<iso-; + Gr. Chora, a place], in thermodynamics, a line on a graph representing the parallel changes in pressure and temperature of something whose volume remains constant.
Isochor, isochore, isochoric: these are all about the process of transformation and sameness. When undergoing an isochoric process, the volume of a given material remains the same even as it undergoes changes in temperature, in pressure. The isochor line reveals the jagged ups and downs of these changes while the material’s volume is constant. How much does this resemble the process of our bodies and our lives? The content, the core of who we are remains constant in many ways, and yet as we endure stresses, fracture, swelling joy, calming neutrality, we are also transformed. Over the course of even one day, our skin flakes off, our hair is falling out and emerging new from follicles, water evaporates from our bodies until we drink to hydrate again, our cells change and adapt and yet our body still maintains a sense of solidity and of consistency so that we can feel our skin, look in a mirror and say, “yes, this is still me.”
Summer Solstice is tomorrow, and so we enter the season of fire. The earth is warmer, our bodies are warmer. Heat is not something to contemplate but a reality. Something that requires us to pay attention to our bodies in a way we might not always pay attention. Last Saturday, I attended a three-hour yoga class to celebrate the solstice. Our teacher asked us: What patterns no longer serve you? What insecurities in your life do you want to burn off? And what, in your life, do you want to set ablaze? As we moved through deep yin yoga poses, strenuous vinyasa, 108 push-ups to serve as prostrations, I could definitely feel the shifts of energy in my body and in my heart and mind, a consistent burning and also a flickering of change. I thought of the constant and yet frenetic nature of a flame, of something on fire. The fire continual, the flame existing as both the same and changing.
For weeks, fires have burned across southern Arizona. The landscape set ablaze, flames consuming all they meet. In the desert, we always pray for rain, but prayers have become more insistent. One place affected is Sierra Vista, a town where I teach. I have been praying for the safety and wellbeing of former students, hoping their homes remain untouched by the fire. Over coffee with a friend, we mentioned our mutual sadness about the fires. She had read the definition of crown fire, the way in which flames leap across the air from crown to crown, treetop to treetop, using gases for fuel until they reach the next branch. The fire is doing exactly what it’s meant to do, she said. Burn. The trouble is when fire burning directly clashes with our health and that of our loved ones, with the place we have chosen to make our home. When fire burning transforms matter in ways that destroy what we have painstakingly built.
Sol + stice derives from Latin words meaning “sun” and “to stand still.” Summer solstice celebrates the longest day and shortest night of the year. When days grow longer, the sun rises higher in the sky until it has the appearance of staticity, of standing still. My yoga teachers say there is no such thing as “balance,” that stillness is an illusion. When we do tree or dancer pose, we are “balancing.” Even as we hold a pose, blood pumps through our vessels, energy courses up and down our bodies, toes clench and release, hips tilt. Druids’ celebrated solstice as the wedding of Heaven and Earth. Ancient Germanic, Slav and Celtic tribes started bonfires, jumping through luck-giving flames. The Tohono O’odham mark solstice as the beginning of the new year, harvesting saguaro fruit into wine named nawait that they drink at vi:gida to bring annual rains. We are moving and motionless. We hold heat and coolness as our earth holds fire and water.
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