Scientists from the University of Queensland have simulated photons or quantum light particles that can move through time and demonstrated how they behave while travelling in wormholes. According to scientists, the experiment shows strange behaviour from the quantum particles, but on a larger scale, time travel continues to be inconceivable.
The group of scientists suggests that at least at the quantum level, the "grandfather paradox" of time travel can be resolved. They discovered that two photons travelling together can interact. In the simulation, the particle stuck in a closed time-like curve is capable of interacting with another photon travelling through regular time and space.
The study was published in the journal Nature Communications and revealed the possible but "bizarre" aspects of modern physics when analysing the behavior of single light particles traveling back through time.
Researchers examined the behaviour of a photon travelling through time and how it interacts with its older self. By simulating the behaviour of the second photon, scientists were able to study the behaviour of the first photon. The results of the study showed how "consistent evolutions" are possible when preparing the second photon in the proper way.
However, time travel for macroscopic systems or larger objects still face "problematic paradoxes."
According to reports, it was predicted in 1991 that time travel was possible in the "quantum world" because small particles behave almost outside the realms of physics. Timothy Ralph, one of the researchers of the latest study, said the properties of quantum particles are "uncertain" to begin with. This gives the photons enough time to move around to avoid inconsistencies in time travel.
PhD student Martin Ringbauer from the University of Queensland said the question of time travel features at the common ground between the physical theories of Albert Einstein's general relativity theory and quantum mechanics.
In Einstein's theory, he suggests it was possible to go back in time by following a space-time pathway that returns to the starting point in space but in an earlier time. This is known as the closed timelike curve (CTC).
The possibility of having a CTC has long baffled physicists and philosophers since it was discovered in 1949 by Kurt Godel, an Austrian-American scientist. The theory of time travel has caused paradoxes in the classical world like the "grandparents paradox" in which a time traveler can stop their grandparents from meeting each other and therefore preventing his birth in the future. If the time traveler was not born, it would make it impossible for him to go back in time in the first place.
However, the new study suggests that at least in the quantum level, the same interaction or behaviour is possible.