Let’s continue the line of reflection we have been involved in – the infinitely small. Let’s focus on ourselves, more specifically on our bodies. Look at your body – your apparently “real,” reliable, stable, predictable body… This is a meditation on process and flux.
Let’s start by thinking of the water droplet. Imagine a drop of rain falling consisting of lots of H₂O molecules. Follow its path in imagination: perhaps into the ground, absorbed by the roots of a tree, contributing to sap, absorbed by the cell, turned into steam when the wet wood is burned….; perhaps into the sewer, into the creek, the river, over the waterfall, into the lake… the ocean, back into the sky. Note that it doesn’t matter what happens to the droplet. It continues to exist even as its state changes radically over time.
Cells in each kind of tissue in our body have their own turnover time, related at least partially to the workload endured by its cells. Epidermal cells, forming the skin of the body, are replaced every two weeks or so. Red blood cells, in constant motion on their journey through the circulatory system, last about 4 months. As for the adult liver, its cells have a turnover time of 300 to 500 days.
Cells lining the surface of the gut are among the shortest-lived in the whole body. The story is very different inside the intestines, however. The average age of intestinal cells is 15.9 years. You see the point. We could multiply the examples.
Think about this for a moment: There’s not one cell in your body that was there when you were born… Our science tells us that matter is neither created nor destroyed. The matter of which our current cells consist has been around since the beginning of time and will be here long after we have gone. Our cells may die, but their atoms merely go on to take on other forms. They get recycled again and again. We are not the matter of our bodies; somehow we “borrow” the matter; we are the shape matter takes for a while before it takes on some other shape; we are temporary structures of matter; everything around us is temporary shapes of matter – here today, gone in a hundred years. So, what is permanence? what is “me”?
We live with our experience of “permanence.” Things simply “are.” We like stability and permanence. We really don’t appreciate change. And we are confronted here—in our very own bodies—with nothing but flux. First we learn that “stuff” is made of almost entirely of emptiness. Then we learn that there is literally nothing in our bodies that have remained constant. So we are forced to ask ourselves what remains? What is constant? Is permanence an illusion and one that we had better overcome? Who am I? What is “me”?
How do these reflections make you feel? Are they reassuring or distressing? What is providing you with the most challenge?