EXCERPTED FROM HERE.

«When we try to translate mathematics and quantum facts into human language, we create an interpretation. The point is that currently there are different interpretations that are incompatible with each other and yet all are compatible with the quantum facts! In other words, there is no consensus among physicists about what quantum reality is. We still can not build a definite mental picture of what’s really going on «down there.»

A novelty that quantum theory brings in relation to classical theories is the existence of a process of observation. Trying to translate mathematics, it works something like this: as free, we describe quantum entities as (hold on to keep from falling out of the chair) doing all that is possible at the same time. Yes, being in all positions, saying yes and not at the same time. But this is very strange and we strive to try to watch this bizarre cabin. However, when we interfere with the quantum system, when we make an observation, something curious happens. The quantum entities when ascertained about what they are doing at a certain time will behave in a classical way. They are in one place, doing only one thing. When observed, the behavior of quantum entities changes abruptly! But what exactly characterizes an observation? What, or who is responsible?

One strand of interpretation that was discussed at the beginning of the twentieth century is that quantum physics represents the fantastic historical moment in which we learn that it is not possible to describe the universe without without reference to the inner experience. That is, somehow consciousness must enter into the equations of physics for a complete description of reality. The observer is us! This view was defended by physicists such as John Von Neumann and Eugene Wigner (and more recently by Bernard d’Espagnat, Evan Harris Walker, Henry Stapp), which became known as a subjectivist interpretation .

With the unfolding of World War II, governments realized the importance of technologies developed by physicists: radar, atomic bomb, etc. To form as many numbers as possible in the shortest possible time, all metaphysical questions were excluded from the process of physicist training (I recommend the book » How the hippies saved physics » by MIT historian David Kaiser). As a result of the process of pragmatization of natural knowledge, subjectivist interpretations have gone out of fashion, giving way to other strictly material views. It is now preferred to believe in the existence of infinite parallel realities than to introduce the uncomfortable subjective ingredient into physics.»