Part 2/10:
Traditionally, physicists have held onto a realist viewpoint—that there exists an objective reality that is wholly independent of our perception of it. This perspective has served science well, presenting the scientist as a detached observer who can investigate and model the world without altering it. However, this notion hit a snag in the 20th century with the advent of quantum mechanics.
Quantum mechanics introduced a revolutionary idea: the act of measurement affects the object being measured, suggesting that physicality cannot even be assigned to the universe until observation occurs. Renowned physicist Niels Bohr argued that “no phenomenon is a phenomenon until it is an observed phenomenon,” challenging the traditional notions of reality.