By, Arizona New Times
Time travel has been a popular topic in science fiction and fantasy for decades, but is it really possible to go back in time and change the past? According to a new study by physicists from the University of Eastern Finland, the answer is no.
The study, published in the journal Optica, explores the behavior of light at the interface between two media, such as air and water. Light usually changes its speed when it passes through an interface, but what happens to its momentum is not well understood. This is known as the Abraham-Minkowski controversy, which dates back to the early 20th century.
The researchers found a novel way to solve this problem by using the concept of proper time, which is a measure of time that depends on the observer’s frame of reference. They showed that light has a proper time that is always increasing, regardless of the medium it travels through. This implies that time in the universe can only go one way: forward.
The study’s lead author, assistant professor Matias 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.”
The study’s co-author, professor Marco Ornigotti, added: “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.”
The implications of this finding are profound, as it suggests that time travel to the past is impossible, at least according to the laws of physics. This means that we cannot alter the course of history, or visit our ancestors, or prevent our mistakes. We can only move forward in time, and face the consequences of our actions.
This may sound disappointing to some, but it also means that we have more responsibility and freedom to shape our future. We cannot rely on a hypothetical time machine to fix our problems, but we can use our creativity and intelligence to find solutions. We cannot escape from the present, but we can make it better.
What do you think about this study? Do you believe that time travel is impossible, or do you still hope that one day we will find a way to break the rules of physics? Let us know in the comments below.