Path Functions

When with a routine set, one’s copin’, /
With mind for surprise of sort, hopin’, /
The morning’s affected 
By sight unexpected: 
A road that was closed now is open!  

The next few Bluesky limericks from April 2026 simply describe occasions set in Spring 2026.  In lieu of “translating” those verses, I am sharing this week a new poem inspired by an early-fall-semester walk near my home, celebrating the benefits of a newly open path.  

“When with a routine set, one’s copin’, /
With mind for surprise of sort, hopin’…“

After several years of teaching, the autumn term is very much a “routine set”; I can predict much of the shape of a given week from what I’ve seen before in terms of teaching and service work.  Similarly, taking a weekend walk is useful, but all the nearby paths are quite well trodden at this point. 

I know enough not to devalue a useful, familiar pattern of any type, but in terms of the scenery, it can be nice to see something new, to notice “surprise[s] of sort[s]” as they arise.   

“The morning’s affected /
By sight unexpected… “

A few weeks ago, I was thus pleased to notice a “sight unexpected,” noticing that a new path had been completed over the summer.  The contrast is most evident from comparing two photos, the first from a previous walk, when the “road closed” sign barred any future progress, and the second from a late-August 2026 weekend, as the road now goes (seemingly) ever on.  

“A road that was closed now is open!”   

It was a welcome surprise to note the new route.  

***

The poem itself likely needs no more context, but it links to the post title via yet another unintentionally poetic phrase from chemistry.  

As I’ve written about previously, in thermodynamics, chemists and physicists use  the descriptors of state functions or path functions to categorize important concepts and calculations.  State functions depend only on initial and final state (e.g., altitude); path functions depend on the path itself (e.g., distance).  The concepts themselves are part of my own “stock of metaphors,” and I’ve written about them here multiple times before.    

Even a simple consideration of the words themselves can turn intriguingly layered. I have often noticed that “state functions” could be read as a sentence, as an imperative that seeks a list of duties from a reader.  (“OK, I’ll state them: I teach; I write…”)  Seeing the now-open trail, I thought this past morning of a parallel simple statement, newly evident: now, the “path functions.”