The 2022 Nobel Prize in Physics highlighted the challenges posed by quantum experiments for “local realism”. However, a growing number of experts are suggesting “backward causation” as a solution, suggesting that current actions can influence past events, thereby preserving both locality and realism. This concept offers a new approach to understanding causality and correlation in quantum mechanics, and despite some criticism and confusion with “superdeterminism”, it is increasingly seen as an increasingly valid explanation for groundbreaking experiments, potentially defending fundamental principles of special theory. relativity

In 2022, the Nobel Prize in Physics was awarded for experimental work showing that the quantum world should break some of our fundamental ideas about how the universe works. Many look at these experiments and conclude that they challenge “locality”—that is, the intuition that distant objects need a physical environment to interact with. Indeed, a mysterious connection between distant particles could be a way to explain these experimental results.

Others, on the other hand, believe that experiments defy “realism”—the intuition that our experience is based on an objective situation. After all, experiments are difficult to explain if our measurements are believed to correspond to something real. In any case, many physicists agree with what local realism calls “death by experiment.”

But what if both of these intuitions could be preserved at the expense of the third? A growing number of experts believe, instead, that we should abandon the assumption that current actions cannot influence past events. This option, called “backward causality”, claims to save both locality and realism.

What is causation anyway? Let’s start with a line everyone knows: correlation is not causation. Some correlations are causal, but not all. Is it important?

Let’s consider two examples. (1) There is a relationship between the barometer needle and the weather – so we know the weather by looking at the barometer. But no one thinks that the barometer needle is the cause of the weather. (2) Drinking strong coffee is associated with increased heart rate. Here it seems correct to say that the first causes the second.

The difference is that if we “move” the barometer needle, we won’t be changing the weather. Air and the barometer needle are controlled by a third thing, atmospheric pressure, so they are linked. When we control the arrow ourselves, we break the connection with the air pressure and the correlation disappears.

But if we intervene to change someone’s coffee intake, we often change their heart rate as well. Causal correlations are correlations that are still valid when we change one of the variables. These days, the science of finding these reliable correlations is called “causal discovery.” A big name for a simple idea: figuring out what else changes when we move things around us.

In ordinary life, we generally accept that the effects of the movement will appear after the movement itself. It’s such a natural assumption that we don’t realize we’re making it.

But nothing in the scientific method requires that to happen, and it’s easy to give up on that in fiction. Likewise, in some religions, we pray to be among loved ones who survived yesterday’s shipwreck, for example. We imagine that what we do now can affect something in the past. This is retro-causation.