20/01/2026
Physicists have conducted a series of experiments that suggest our choices in the present can influence what happened in the past - at least on a quantum level. In one version of the “delayed-choice” experiment, a single photon goes through a double-slit and gets paired with another photon. Scientists can decide after it passes through whether to find out which slit it went through or to erase that information.
Strangely, the results change depending on that later choice.
Later experiments made sure this wasn’t just a trick of timing. Researchers placed the detectors far enough apart that no signal could travel between them in time to influence the result, yet the pattern still depended on the delayed decision.
In 2023, scientists in South Korea went even further and found that whether light showed an interference pattern or not depended entirely on a measurement made after the photon was already on its way.
All of this points to the fact that the past isn’t fixed until we observe it. Reality seems to exist in a kind of “maybe” state until our observation locks it into place. It challenges how we think about time, cause and effect, and even our role in the universe. Maybe we’re not just watching reality unfold - we’re helping to create it.