Supermarkets are a part of everyday life for the people of the developed nations of planet Earth. They have a similar form the world over: long aisles, harsh fluorescent lighting, day-glo specials stickers, prices that end in .99, lame trolleys (note that this is not the trendy US use of the word "lame." This is lame as in "having only one foot.") and awful music (in fact the term "supermarket music" now rivals "elevator music" as the most appropriate characterization of bland easy-listening covers (of what in some cases were once good songs) featuring trombones and sounding like a high-school big-band on Valium).
The uniformity of Supermarkets the world over doubtlessly appeals to proponents of "morphic field" theories. According to these theories, the "morphic field" of a physical body is what causes it to have the shape that it does. (From the Ancient Greek root "morph-" meaning "form," though in this particular case it may have been the little-known second meaning - "utter crap" - that was used.) Such theories would claim that the uniformity of supermarkets arises from some sort of "morphic resonance" - the morphic fields of Supermarkets the world over somehow affecting each other and causing themselves to become uniform.
This may be so. The author suspects that the fact that they are mostly owned by the same multinational conglomerates has something to do with it as well.
What is certain, however, is this: the Earth, in addition to the well-known gravitational and magnetic ones, has a Murphic field. (Named, according to convention, after the law to which it is related, i.e. the Law of Gravity, the Law of Magnetism (well, Maxwell's equations), Murphy's Law, etc.). The Earth's Murphic field covers the entire planet, and, like the other fields, has local variations in intensity. Supermarkets occur at those points at which the Earth's Murphic field is strongest.
At this point it is worth digressing a little to discuss Murphy's Law, which is traditionally stated as: "If something can go wrong, it will." This is clearly not a physical law in the usual sense, because it is not always true (as the occasional correct spelling of words in this article, for instance, demonstrates). Why, then, call it a law? I direct the reader to another well-known example: the speed limit. Here is an example of a law that is only occasionally obeyed.
I suspect that a probabilistic interpretation is the most appropriate one for Murphy's Law. Just as the amplitude of the wave function of an electron in Quantum Mechanics indicates the probability of finding the electron at a given point, so the amplitude of the Murphic field indicates the probability of Murphy's Law holding at that point.
In Supermarkets the amplitude of the Murphic field is 1.
(Keen observers, and those who have studied Quantum Mechanics, may spot a problem here. How can the probability amplitude be one in more than one place? Perhaps we need to renormalize Supermarkets? I boldly conjecture an alternative explanation: all Supermarkets are in fact the SAME Supermarket! This, like all good scientific theories, makes a new prediction: all Supermarkets should thus look the same. But this is just what is observed! Thus, in a bold stroke, I solve two Supermarket paradoxes, though admittedly causing some as-yet-unsolved problems for the topology of the planet. Even keener observers will have spotted that I am talking absolute nonsense. Fun isn't it?)
The consequence of the amplitude of the Murphic field being 1 is obvious. Everything will go wrong if it can. That's the Law.
I have already described some of the things that go wrong in supermarkets: the lighting, the music, and the trolleys. Here is a brief list of some of the others: the meat (especially the steak), the no-brand "cheese," the bags that are not strong enough, and the fish. Especially the fish. For a long time I assumed that it must be true of the fish. I was recently foolish enough to confirm it by experiment.
There are also grave problems with the tomatoes.
The point in a Supermarket at which the Murphic field is strongest is the check-out (no correspondence will be entered into on just what sort of probability is greater than 1). The vigilance with which Murphy's Law is enforced at the check-out would have pleased Mussolini (had he been Irish - Murpholini?). All people who have frequented Supermarkets will be familiar with what I shall refer to as the "queue game." You know what I mean. You arrive with your selection of "goods" and try to work out which queue will get you to the cash register fastest. It is possible to lose this game, and, according to Murphy's Law, you will. (This is also true at banks with automatic teller machines).
What is seldom realized, however, is that Supermarket queues are perhaps the only macroscopic version of the famous "Schrodinger's Cat" experiment. This is how it works. Before you join a queue, the shoppers and cash registers in all the queues exist in a superposition of states. When you make an observation of the system (by joining a queue), you cause the queue wave function to collapse. The system is now in a definite state. And the state in which it is now in is this: in your queue is someone whose milk carton is leaking and will need a replacement ("Service 9 on 10"), another guy who is only buying a chocolate bar but wants to pay using electronic funds transfer to debit his bank account directly, a person in front of you who is going to have his bag of flour break right on the scanner so that it stops working, and a mother with a child with chocolate on its hands that is soon going to be on your shirt. The roll of paper in the cash register is going to run out too.
The fact that there was a superposition of states prior to your joining a queue can be seen from the fact that the above is true independent of the queue you join. As soon as you make the observation the wave function collapses. And it collapses on you.
The Supermarket check-out is not only an example of the rare phenomenon of a macroscopically observable quantum effect (here interacting with a Murphic effect). This example, in fact, provides strong evidence for the Everett "Many-Worlds" interpretation of Quantum Mechanics. Briefly stated, in this interpretation an observation causes a multifurcation of the universe. A universe exists for each possible outcome of the observation. This is perhaps the only interpretation that can explain the data observed in Supermarkets. Squire's Check-Out Law (a corollary of Murphy's Law, stated above) must hold for every person in every queue. The only way this can be true is if the act of joining a queue for each person creates a universe in which that person loses the queue game. In your universe, the other queues move faster. Everyone else thinks this too. (Perhaps there is some sort of relativistic explanation here? Maybe the speed of a supermarket queue in which you are in is an invariant, but looks faster from any other frame/queue. The "Many-Worlds" interpretation may not be necessary after all.)
So we see that Supermarkets have their own special Physics.
And their own "special" fish.