Seven people have considered sitting here -

before noticing this coffee cup and moving on.

I know this, becuase I was one of them.

There are 40 benches in this particular train coach. 20 of them seat three and 20 seat two. That's 100 potential seats on one carriage of five.

Presented with such an abundance of choice at the beginning of the line, how does one decide where to sit?

This should be an ideal seat on a day like this.

Sometimes, taking a two-seat bench is risky. The train starts to fill as it approaches the city, and on a busy day, the two-seat-bench passenger is likely to be cheek to cheek with a neighbor well before the end of the line.

Safer, then, to take one of the triple-seat benches, which are hardly ever fully utilized. On the triple-wide side of the train, you're guaranteed to share your seat before the end of the ride, but you'll always have a comfortable ass-margin between you and your companion.

This, however, is the Friday before Memorial Day weekend. A beautiful sunny one at that. If the state of the commuter rail parking lot is any indication, lots of regular travellers have chosen to make an even longer weekend of it and stay home today. (I got a choice parking space: No. 18, right next to the platform. But the over-analysis of that selection can be left for another post.)

So, even compensating for the fact that the transportation authority has sent us five single-story coaches, effectively cutting the seating selections in half, the chances of arriving comfortably in the city with a double seat to oneself are pretty good.

Making this seat even more desirable is the location on the west-facing side of the northbound train. This guarantees shady, comfortable views, no glare on the laptop screen, and a well-balanced body temperature without the springtime sun roasting one side of the face through the window, or the production of one sweaty armpit.

The seat's also in pristine condition. No tears or cuts. Only the slightest of gluttial grooves. Why, then, should it remain unoccupied?

People clearly want to sit there.

But there is the matter of that coffee cup.

People unshoulder their bags and take a single step towards the seat. They notice it, and they step away, coats half-off and bags now hand-carried.

It's almost a subliminal reaction. I doubt many will remember the impact of this shell of plastic and cardboard, which possibly contains no coffee at all. In fact, as they settle in and the train starts rolling, they have surely forgotten about it already.

There are lots of reasons to avoid this seat, and this cup.

There is no easy place to dispose of it, and doing so would involve going to one end of the car or the other, against the flow of subsequent boarders.

It would also involve physical contact and the possibility of disease transmission. Nothing is more unpleasant to the sterility obsessed American mind than touching something that may have been in other hands - and touched other lips! - without rubber gloves and a bottle of hand sanitizer at the ready.

So the sitting traveller would be left to observe the cup for the entirety of the trip, in a state of low-grade anxiety, wondering if at any moment it might topple and roll, and if it did, would it be full, and if it were, would the contents spill, and if they did, would they land on their nice city clothes, and if they did, would they stain?

There's a whole universe of day-altering misfortune, right there.

There are social implications to sitting next to someone else's garbage.

Whether the cup fell during the inbound voyage or not, any nearby passenger would take on some guilt by association. Proximity suggests ownership. Another passenger, seeing you sitting next to this cup, might assume you had brought it on board yourself.

No shame in that, of course - until the end of the voyage. At that point you'd be obligated to take it with you - risking the same possibility of disease transmission that discouraged you at the beginning of the voyage.

Worse, if the cup did fall and roll and spill on other passengers, or discharge a stream of fluid that spread below several seats, octopus-like, with glistening tendrils pointing back to the spill's epicenter beneath your seat, why - this could lead to the sort of condemnation and ostracism it's better not to think about - even if it would be held in other passengers' heads, unexpressed until forgotten.

People wax philosophical about the butterfly effect.

But I say we can affect even more world-altering change with a piece of litter that's just sitting there.

UPDATE:

A woman took the seat. She's African-American, with these fabulous tight braids, half of which are dyed lime green and the other half left black. She's got earbuds in, and is bopping her head around in a state of indulgent pleasure I only wish I could get from music.

But I notice she is sitting on the right hand seat of the bench, rather than next to the window.

Who does that?

The Coffee Cup is all-powerful. All respect and praise to the Coffee Cup.