What is permeability? What does it mean when something is permeable? What do we mean when we say something has permeated something else? In class we discuss the semi-permeable cell membrane in detail, but we never really discuss the concept of permeability. It seems that the idea of permeability has to do with the movement of one substance across a boundary, but that is a very general and perhaps incomplete concept. What is a boundary? What is the substance? Does permeability have only to do with size? Porosity? Chemistry? Can we think of permeability in other ways? In common language we use the term permeable in many contexts. For example, we say that people in love are permeated with attraction for one another. Can permeability also relate to vulnerability? In another context we may say that a product has "permeated" the market. Does this imply strength?
As a scientist and an artist I think there are many ways to look at concepts we might otherwise take for granted. We can learn a lot this way. And by exploring "scientific" concepts from different angles, perhaps we can understand more about the properties, propensities, and possibilities of our world.
Here's an example. In this experiment with ceramics I made large balls of newspaper, then covered them with ceramic slip impregnated with salt. I "glued" the balls together with more goopy clay. Once my sculpture was dry I stuck it in the kiln and baked it for a couple of days. Fortunately or unfortunately, depending on how you look at it, the thing broke apart as I pulled it out of the kiln. But I got to learn a lot about the behavior of my materials.
Look closely at the mess I made and you can see that this is actually an experiment in permeability! How effectively did the slip permeate the newspaper? The thin paper-like formations are actually ceramic "paper," so you can say the permeability of clay slip into paper was pretty effective. Now look at the purple-blue color. That's the salt, vaporized in the heat of the kiln and able to then permeate the almost-molten clay. What do we see here? The salt did not penetrate the whole structure. Reasons unknown. But we have learned more about permeability. To be a bit more "scientific" we have learned something of how a vapor permeates a semi-solid substance in the oxidizing environment of a high temperature kiln.
My next example is from a store window in the incredible Centro Historico of Mexico City. I took this picture when I was preparing for an art residency there, which was supposed to focus on movement and materials of this vibrant market district. Pictured here are bags of plastic objects. The objects themselves are permeated with color. The plastic bags block some of that color and the window glass blocks it more. The lens of my camera blocked more of the color, as did the air between the window and my camera. We could go on. But here the question of permeability arises again. How "permeated" with color is this photo? And how "permeated" with color were the original plastic objects? You can see that in this example we are discussing permeability in a context that is different from my ceramics experiment.
I think we could go on about questions of permeability all day. Probably there have been lots of books written about it. From philosophy to thermodynamics, permeability is a huge question. I like to stay somewhere in between, in the world of biology. I also like to keep my blog posts short. So take a look (or should I say take a sniff) at the photo below. Lilacs. Beautiful luscious harbingers of spring, fragrant, delicious, rich appealing aroma. They permeate the atmosphere with their visual and olfactory generosity. Who says science and art are miles apart?