10/11/2025
Physicists in Copenhagen have observed a phenomenon that seems to bend time itself. Experiments show that particles can change their past state depending on how researchers measure them in the future. This paradox, known as retrocausality, suggests that cause and effect may not always flow forward.
In the experiment, a photon traveled through a set of detectors. The decision of how to measure it was made later, yet that choice influenced the photon’s earlier state. It’s as if the universe anticipates the choice and adjusts history accordingly. Scientists describe this using quantum superposition: until a decision is made, the past remains undefined. Once a choice occurs, the past seems to “fill in” to match it.
This challenges our everyday understanding of time. Particles do not separate past and future; they exist in a state where all moments are connected. If retrocausality is real, then every decision we make might be shaping history itself, not just responding to it.
Skeptics remain cautious, but the findings open the door to one of the strangest possibilities in physics: the past is not fixed until we decide what it will be.