Time only moves forward… or does it?
Scientists in Russia have managed to turn back time! It was for a very very short duration of time, but they did it!
It is widely believed in the world of physics that time, despite being relative, only moves forward. Einstein already showed us that time can be slowed down, based on his theory of relativity, which has been observed and is important for all our GPS devices to work! However slow time is though, it was always believed to move in one direction – forward. This notion is one of the foundations of the second law of thermodynamics, which is integral to many areas of physics. Besides even physics, this notion is a part of our everyday lives! The Arrow of Time dictates that as each moment passes, things change, and once these changes have happened, they are never undone. In the life of the universe, just as in our lives, everything is irreversibly changing.
Physicists in Russia, in collaboration with physicists from the USA, managed to bend this widely held notion. Researchers from the Moscow Institute of Physics and Technology (MIPT) teamed up with colleagues from the US and Switzerland and returned the state of a quantum computer a fraction of a second into the past. To test their hypothesis, they decided to observe a single, solitary electron, in empty, uninterrupted space.
The team observed many such electrons, and calculated the definite probability of an electron going back in time. In modern physics, probability is everything, and calculating a definitive probability for an event taking place is as good as observing it!
The universe is estimated to be 13.7 billion years old. The scientists found that even across the entire lifetime of the universe, observing 10 billion freshly localized electrons every second, the reverse evolution of the particle's state would only happen once. Yes, that’s how low it is, BUT it still does exist. This means that in the history of the universe, this has happened once before.
If you’re wondering how far back in time the electron travelled, it was less than one billionth of a second.
These results may not be impressive, but the fact that such an event could even happen is revolutionary! It has questioned one of the most fundamental pillars of our knowledge, and, with future advances in technology, science fiction could become a reality and time travel could be possible !