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Public Transit Commuter Repulsion Theory
Feb 2, 2008 | Lucas
It is always intriguing to see how fundamental concepts in physics and chemistry can scale up from a sub-microscopic level all the way up past human size. As an example, let's take the Valence Shell Electron Pair Repulsion (VSEPR) Theory.
First a very brief, oversimplified overview of the VSEPR Theory that will make any chemist twitch and cringe with frustration: An atom has a nucleus around which electrons orbit. The electrons are attracted to the nucleus but they are repelled by each other. Thus, each electron will try and get as far away as it can from every other electron in order to reach its lowest energy state.
I have been taking the bus and SkyTrain to UBC nearly every weekday since September, and it has always fascinated me how people choose which seat to sit in. This past Friday in particular was a clear example of the Public Transit Commuter Repulsion (PTCR) Theory in action.
I was on the old boxy-looking Expo train where the seats in the middle faced each other. The train was fairly packed but despite people standing, there were free seats scattered throughout the train. My assumption is that the repulsive force exerted by the two people sitting on either side of the empty seat was too great for someone else to be able to sit down in between, thus their lowest energy state would be to remain standing.
However that's not the strangest part of it all. As the SkyTrain pulled up to Commercial Drive where the majority of the people got off, something absolutely phenomenal happened. Two people remained on each side of the seats facing each other, and each person was sitting at one extremity of the bench. The remainder of the people were sitting one person per row (on opposite sides) on the benches facing the front and back. How is that for PTCR repulsion!
Of course, the PTCR theory will not always be so clairvoyantly visible, however it is still present in each SkyTrain ride you take. Here's a more common example. You have a bench on the old expo line as such (where the [ ] denote the domain of the bench, the | denote the metal poles, the letters W, X, Y, Z denote people and _ denote empty seats):
[W_|_X|_Y] Z
Despite there being an empty seat between person X and Y, person Z will continue to stand. However, as soon as Y gets off, Z takes his spot:
[W_|_X|_Z]
So next time you take the SkyTrain, take note of these natural forces at work.