by Team Physics-Astronomy
Scientists from the University of Queensland
photons (single particles of light)
The research is
and the results
could be dramatic!
The research is cutting edge and the results could be dramatic!
Their research, entitled
"Experimental Simulation of Closed
is published in a issue of
The grandfather paradox states that if a time traveler were to go
back in time, he could accidentally prevent his grandparents from
meeting, and thus prevent his own birth.
However, if he had never
been born, he could never have traveled back in time, in the first
The paradoxes are
largely caused by Einstein's theory of relativity,
and the solution to it, the
How relativity works
Einstein's theory of relativity is made up of two parts:
and special relativity.
posits that space and time are aspects of the same thing, known
as the space-time continuum, and that time can slow down
or speed up, depending on how fast you are moving, relative to
Gravity can also bend
time, and Einstein's theory of general relativity suggests that it
would be possible to travel backwards in time by following a
space-time path, i.e.,
a closed time-line
curve that returns to the starting point in space, but arrives
at an earlier time.
It was predicted in 1991
quantum mechanics could avoid some
of the paradoxes caused by Einstein's theory of relativity,
as quantum particles behave almost outside the realm of physics.
"The question of
time travel features at the
interface between two of our most successful yet incompatible
physical theories - Einstein's general relativity and quantum
describes the world at the very large scale of stars and
mechanics is an excellent description of the world at the
very small scale of atoms and molecules",
Ringbauer, a PhD student at UQ's School of Mathematics and
Physics and a lead author of the paper.
The scientists simulated
the behavior of two photons interacting with each other in two
In the first
case, one photon passed through a wormhole and then
interacted with its older self.
In the second
case, when a photon travels through normal space-time and
interacts with another photon trapped inside a closed
time-line curve forever.
"The properties of
quantum particles are 'fuzzy' or uncertain to start with, so
this gives them enough wiggle room to avoid inconsistent time
travel situations," said co-author Professor Timothy Ralph.
"Our study provides
insights into where and how nature might behave differently from
what our theories predict."
Although it has been
possible to simulate time travel with tiny quantum particles,
the same might not be possible for larger particles or atoms, which
are groups of particles.