Great Scott! Could time travel soon become a reality? Physicists simulate sending quantum light particles into the past
- University of Queensland scientists simulate photons moving through time
- They showed how two wormhole-travelling photons might behave
- Time-travel in the quantum world seems to avoid famous paradoxes
- The experiment shows bizarre behaviour of such quantum particles
- But on larger scales time travel still remains implausible, say researchers
If a time traveller went back in time and stopped their own grandparents from meeting, would they prevent their own birth?
That’s the crux of an infamous theory known as the 'grandfather paradox', which is often said to mean time travel is impossible - but some researchers think otherwise.
In the simulation, the researchers examined two possible outcomes for a time-travelling photon.
In the simulation, the researchers examined the behaviour of a photon traveling through time and interacting with its older self.
In their experiment they made use of the closely related, fictitious, case where the photon travels through normal space-time and interacts with another photon that is stuck in a time-travelling loop through a wormhole, known as a closed timelike curve (CTC).
Simulating the behaviour of this second photon, they were able to study the behaviour of the first - and the results show that consistent evolutions can be achieved when preparing the second photon in just the right way.
By definition ‘quantum’ refers to the smallest possible particles that can independently exist - such as photons.
However, for macroscopic systems time-travel still faces problematic paradoxes.
In 1991 it was first predicted that time travel would be possible in the ‘quantum world’ because quantum particles behave almost outside the realms of physics.http://www.dailymail.co.uk/sciencetech/article-2665781/Could-time-t...