Pondering the Residence Time of Supermarket Green Peppers – or – On The Similarities Between Environmental Chemistry, Yuppies, and Jim Henson’s Fragglerock

This weekend, like every weekend, I ran out of food to eat in my apartment. I only buy enough groceries to make as many lunches and dinners as I will eat in two days, typically from a single bout of cooking. This saves me time, while providing my taste buds a break from a potentially mundane week.

So, I headed up the street to my cozy little fruits and vegetables stand – past the leather porn shop with the burly looking man standing in the doorway and smoking, past the James Bond-looking mannequin with his crotchless pantie adorned harem in the fantasy porn shop’s window display, past the wall of brightly coloured glass bongs and some dude with dreadlocks in the pot paraphernalia shop, past all the tourists taking in large sinful eyefuls through their sideways gazes, and past one great and a few decent Greek restaurants.

Call it a personal phenomenological revolution, or maybe just “growing up”, but more and more often I find myself relating what I study to what I experience.

Standing in front of the green peppers, I pondered, “How the hell do they sell these so damned inexpensively? They are half the price of the green peppers sold at Safeway – what gives!” The answer is a simple case of economics: sell at a cheaper price, out-compete your competitors, sell more than you would otherwise, and thusly take home boxes of money.

However, this wasn’t the first explanation that came to my mind. In fact, as long as they remained as cheap as they were, I doubt I would think anything of it. Instead I thought about residence times. But, before going on, lets talk more about me first. Everyone likes talk about themselves, right? So no one should have a problem if I continue to do so? Great!

I study how chemicals are “transformed” or “move” between different “reservoirs” in the ocean. These processes involve various chemical “transformations”, including abiotic (you know, stuff sticks to other stuff, stuff sinks) and biotic (living stuff eats and poops stuff, which in turn is eaten and pooped by other stuff, interspersed with sex of sorts – rah rah biology!). Take the following profile as an example:

downtown depth profile

  • Vancouver: In the West End and Yaletown, life is carefree and near whimsical for the resident yuppies, but no one can afford to live there for long – although there’s plenty of fun and debauchery to go around, you’re bound to run out of money, unless you’re. Therefore, trendy downtown residents inevitably migrate south and east in search of cheaper rent.
  • Science: In the open ocean, single celled plant-like cells (phytoplankton) in the top 100 or so meters of the water column are usually not limited by light availability. However, as these cells take up nutrients and sink below the wind-mixed surface layer, they effectively “pump” nutrients from the surface to depth. The resulting profile reflects this “draw down” of nutrients from the top of the water column to deeper depths. Meawhile, bacteria munch away at dead organic matter, “remineralizing” or releasing the inorganic nutrients back into the surrounding water.
  • Vancouver: At Main and Terminal, the Skytrain station is abuzz with commuters. Pickpockets, ner-do-wells, no-good-nicks, shenanigans and bad motha’s are having a heyday, robbing transit patrons as they make their way around the city. It has, at times, been referred to as the cities’ “orifice where the sun don’t shine”.
  • Science: Below a few hundred meters, light is effectively attenuated, and photosynthesis can no longer occur. The sinking particulate matter is broken down by bacteria into the original organic constituents it started out as, thus gaining energy to proliferate (i.e. like humans, bacteria “eat” organic matter, “breath out” carbon dioxide).
  • Vancouver: In the Kensington area, young families quietly go about their business, oblivious to the yuppies, hipsters, and all out weirdo’s that call downtown and Mount Pleasant home sweet home.
  • Science: Deep below the surface of the ocean, things are calm and quiet. Deep currents are much slower than at the surface, and very different groups organisms have evolved to thrive in this region of the water column. In particular, the process of nitrification, or the conversion of ammonium (product of heterotrophic organisms) to nitrate by bacteria fuels a number of groups of chemoautotrophs (instead of light, they use potential chemical energy to make their own food).

The backbone of this field relies on one vital determination: whether the system is at steady state or not. For a system to be at steady sate, the rate of the element of interest going into the reservoir must be equal to the rate of it leaving the reservoir. Now, assuming this to be true (which is typically the case – depending on the time scale you’re interested in), one can determine a “residence time”, or τ:

τ = total amount of chemical A in the ocean ÷ rate of supply/removal of A

= some unit of time

= the time it takes a single atom or molecule of A to enter and leave the ocean

τ is very handy for a number of reasons, most notably how it provides the user an intuitive sense of what processes might influence chemical A over a given period of time.

Perhaps a more familiar example will help to explain this: the doozers from Jim Henson’s Muppet offshoot hit Fragglerock.

Doozers are small, communal creatures in the land of Fragglerock, and make a living building architectural masterpieces out of radish dust (and, presumably, a little doozer spit, sweat and blood). Although small in stature (6″ tall) doozers are big on work ethic: they build as long as there is space to build. However, since Fragglerock consists a series of underground, confined tunnels, space is very limited. Fraggles, on the other hand, love to eat the doozer buildings. But the thing is, Doozers dig the Fraggles – otherwise, they’d have no more space to build, cooperate, and otherwise sing songs of the working class.

[Doozers building in Fragglerock – source]

Think about Fragglerock as the ocean, and:

  • Buildings = chemicals
  • Doozers = processes that supply chemicals to the ocean
  • Fraggles = processes that remove chemicals from the ocean

As Doozers build buildings, Fraggles eat them. The more buildings that are available, the more often the Fraggles mow down (think of it in terms of “eating out of convenience”). Therefore, although the system is dynamic, the total number of buildings remains constant over a long enough time period.

Now, I wonder what Fraggles or Doozers would think about residence times if they weren’t simply metaphysical extensions of Jim Henson’s personality stuck to puppeteers’ hands?

If they’re at all like me, walking home with a bag full of peppers they’ll start asking themselves, “I wonder whether bongs or pipes are more likely to be at steady state with respect to their purpose?  Dreadlocks?  Hardly the case. What is the residence time of cigarettes in that burly man’s leather pants? Can a good restaurant be gaged by the length of the line-up outside, or does this indicate poor service and a longer residence time of patrons?”

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Dave Semeniuk spends hours locked up in his office, thinking about the role the oceans play in controlling global climate, and unique ways of studying it. He'd also like to shamelessly plug his art practice: davidsemeniuk.com