Tomorrows

[Boydstun]

Daybreak

J – Grüß Gott, Izzy!

I – Good Morning, Joey!

J – Kaffee?

I – Danke! The garden in this light is something else.

J – You in that easy satin robe are something else.

I – But that our reach exceed our grasp, or what’s a heaven for?*

J – Annie said the sun comes up tomorrow. That was only a metaphor for the human lot, of course. But literally, how would she know the sun would come up again?

I – An invariant run. But Melancholia, you know.

J – And you?

I – Spin of the earth is long as earth, but for arrival of external torque. Radiation out sun is long as its fusion. Shade of earth by a celestial body is not in prospect tomorrow.

J – May I kiss you?

I – So many days have not yet broken.*

*R. Browning, Rig Veda

[Boydstun]

Garden Light

J – Welcome to my after-garden, Izzy! I’ve gotten daffodil bulbs to add, but I’m savoring summer a few minutes more. Admiring the brown of my feet, before boots.

I – How can I help?

J – Use the digger to make fifty holes in this part, six inches deep and about eight inches apart. Do not tumble down the hill.

I – What are you going to do?

J – Attend to your every position. Then issue your next instruction.

I – There are other wonders of the world. Why do your bare feet on a step-stone today feel cooler than your feet on the soil? After all, we know perfectly well the stone and soil are in thermal equilibrium. They have the same temperature.

J – You are very educational. And when you speak of such things, I imagine all the more positions, bed and floor.

I – Spring eternal?

J – Whichever comes first: either as long as it takes or as long as it takes. By the way, I do know how the stone and soil heat-thing works. Awaken to me.

I –  Speak the science of the stone and soil paradox.

J – We have skin receptors responsive to rate of heat flow into or out of the body when contacting materials with a different temperature than body temperature. Flow rate is slower into or from insulators such as air. And the dry soil is more insulating than the stone. So heat from my feet flows at a higher rate into stone than into the dry soil. Useful in philosophy? Stone floor? With rug?

I – I raise an eyelid. Let’s do the bulbs, Joey.

J – Tomorrow is another day.

[Boydstun]

Chambered

J – I’ve blazed up the fire in the fireplace. Come sit by me, Izzy. Yes, here. Speak again the science of the living chambers. I’ll play my part.

I – Typically, each macromolecule, such as a protein or a nucleic acid, inside a living cell tends to carry many excess negative charges. These charges get balanced by positive ions, especially potassium, dissolved in the water within the cell. But the presence of these ions means that water tends to be drawn into the cell by osmosis. This osmosis is not on account of electrical charge on the potassium ions, but merely because potassium is not water and nature abhors concentration gradients among species of chemicals.

J – What keeps the cell from swelling and finally bursting as more and more water is taken in?

I – The walls of plant cells are made pretty strong. The pressure inside the cells can therefore be higher than outside, and this higher pressure inside opposes the osmotic flow of water into the plant’s cells. Notice the passivity of this solution for the problem. That is one stable solution to the problem that began with the fact that the molecules of life have excess negative charge. It is a rather simple-minded solution, however, and this is why to this day plants do so poorly on IQ tests (J. Enright, personal communication).

The membrane forming the boundary of an animal cell is hardly a wall. It is usually not called a wall, but a membrane. The membrane is so thin it cannot withstand any pressure difference across it. Such a cell must live a bit more dynamically with its surround. It will be surrounded by water molecules just teeming to get inside and dilute the concentrations of dissolved chemical species (especially ions of potassium, but also sodium and chlorine).

J – What to do?

I – First, take stock: the cell membrane is permeable to water, to potassium, to sodium, . . . and not permeable to chlorine. The membrane is more permeable to the potassium than to the sodium. 

J – Hummm.

I – Try this: pump sodium ions out. As it happens, doing that will simultaneously pump more potassium ions in from the outside. Then the pump—if it reaches a steady state before burning up—will be able to maintain a higher concentration of sodium ions outside than inside. Then the sodium ions outside will be diffusing across the membrane, trying to sneak back in, and the potassium ions on the inside will be diffusing across the membrane, trying to get out to the suburbs. Voila! Since the membrane allows potassium to get out more freely than it allows sodium to get in, the net effect of the pump will be to increase the concentration of particles that are not water on the outside, thereby making the water molecules content to just stay out there.

J – Don’t start the pump! Check all angles, engineer Izzy!

I – Consider the electrical situation. Both the potassium ions and the sodium ions carry an excess positive charge. Since the pump will be decreasing the overall concentration of these on the inside of the cell, the excess negative charge on the inside (macromolecules and chlorine) will not be entirely cancelled out by the dissolved positive ions inside. Then the cell membrane will have an electrical potential difference across it. The cell can live with that provided the pump speed is restricted to a certain range implicated by the membrane’s electrical conductance with respect to sodium ions relative to its electrical conductance with respect to potassium ions.

J – Glory be. Start the pump.

I – The momentous spin-off in evolutionary history was that this membrane potential, in some animal cells, could be briefly changed by adjustments in the membrane conductances with respect to sodium ions and with respect to potassium ions. Thus the animal-cell solution to the problem that the molecules of life (the macros inside the cell) carry excess electrical charge made possible the essential signaling mechanism (brief change in membrane potential) for muscle cells and for nerve cells (neurons). And that is how it came about that some animals today can talk and write and study, say, science and philosophy. (1994, 121–23)

J – Amen.

I – Want to pump, Joey?

J – Let us now Hobbes-farewell our companions.

I – But whatever shall be the method you will like, I would very fain commend philosophy to you, that is to say, the study of wisdom, for want of which we have all suffered much damage lately. For even they, that study wealth, do it out of love of wisdom; for their treasures serve them but for a looking-glass, wherein to behold and contemplate their own wisdom. Nor do they, that love to be employed in public business, aim at anything but place wherein to show their wisdom. Neither do voluptuous men neglect philosophy, but only because they know not how great a pleasure it is to the mind of man to be ravished in the vigorous and perpetual embraces of the most beauteous world. Lastly, though for nothing else, yet because the mind of man is no less impatient of empty time than nature is of empty place, to the end you be not forced for want of what to do, to be troublesome to men that have business, or take hurt by falling into idle company, but have somewhat of your own wherewith to fill up your time, I recommend unto you to study philosophy. Farewell.

Edited April 10, 2024 by Boydstun