One of the most wonderful aspects of football is that with a ball, everyone plays. The goals can be defined with stones, shirts, or anything that stays still. In fact, the "ball" only needs to be an object sufficiently spherical or round to accompany the action. However, imagine for a moment that the ball is actually a wave function trapped in a quantum system, and that "goals" are scored purely by probability. Welcome to Quantum Soccer.
With the introduction of VAR, football rules are being analyzed as never before. One of the most controversial points remains the offside: the natural margin of interpretation in these plays clashes head-on with the absolute profile of VAR, leading to goals disallowed by a shoulder or half a knee. The solution? Change the rules: The new "Wenger variant" suggests marking an offside only when the attacker's entire body exceeds the last defender.
But what happens when the rule changes don't stop there? Well, we could say that other forms of football are born. Football with bicycles (radball), football with motorcycles (motoball), paddle football (jorkeyball), football with skates (roller soccer)... and quantum football. At least, that's what what science fiction writer Greg Egan proposes. Needless to say, quantum football doesn't have a real-life version, and only exists on the writer's personal page, but it's still something very curious.
How to (try to) play quantum soccer
The official description of quantum football indicates that the objective of the external player (that is, us) is to modify the wave function of a "quantum ball" until its probability of entering one of the goals rises above an arbitrary threshold. How is this achieved? Using the movement of the players on the field to alter the energy spectrum of the wave function. When one of those players moves across the field, the energy of that action provides or absorbs transitions between different modes of the wave function.
Believe it or not, "that" is the basic explanation, a humble translation of what I found on the site. Egan published the necessary instructions to control the players that modify the wave function, and a series of mathematical details with formulas that unfortunately completely surpass me, but there is something more: A story. As I mentioned above, Egan is a writer, and his story "Border Guards" explores the development of a quantum football game. There is no Spanish translation, but you can find it here.
Official site: Click here.
