It’s a hypothetical concept which has fascinated mankind throughout history in both the world of science and fiction, but could we be closer than ever to discovering the existence of time travel?
Well no, not exactly.
However, scientists have released a new study which might just change our understanding of what could be theoretically possible regarding time travel.
In essence, the new research basically rules out the concept of every being able to head back in time.
A new study has stated that time in the universe can only go one way – and it’s all thanks to a new study into light and its relationship with other objects.
However, because time as a concept is now being framed in this way, of only being able to move forward in the universe in a linear fashion, the new research points to going backwards in time being an impossibility.
The speed of light often changes when it passes through an interface, but the actual breakdown of what happens at the interface has never been known for certain.
Assistant professor Matias Koivurova from the University of Eastern Finland is the lead author of the study published in the journal Optica, which has come up with a new answer which relies on arguing that the universe has one space dimension and one time dimension.
Essentially, they posited a solution to the question of what happens to the momentum of light around an interface – and that solution relies entirely on time moving exclusively forwards in the universe.
Koivurova said: “Basically, I found a very neat way to derive the standard wave equation in 1+1 dimensions. The only assumption I needed was that the speed of the wave is constant. Then I thought to myself: what if it’s not always constant? This turned out to be a really good question.”
Study lead Professor Marco Ornigotti also said: “There is this very famous debate in physics, which is called the Abraham-Minkowski controversy. The controversy is that when light enters a medium, what happens to its momentum? Minkowski said that the momentum increases, while Abraham insisted that it decreases.
“We found that we can ascribe a ‘proper time’ to the wave, which is entirely analogous to the proper time in the general theory of relativity.”
If time is only moving forwards in the universe, then those dreams we have of revisiting the past may well remain the stuff of fiction.
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Dr. Thomas Hughes is a UK-based scientist and science communicator who makes complex topics accessible to readers. His articles explore breakthroughs in various scientific disciplines, from space exploration to cutting-edge research.
