The concept of time travel is a fascinating topic and has been explored in various ways in science fiction. However, according to our current scientific understanding, time travel, particularly backward time travel, is not considered possible.
The idea of traveling back in time often leads to paradoxes, such as the famous "grandfather paradox." This paradox suggests that if you were to travel back in time and prevent your own birth or cause harm to your ancestors, it would create a contradiction. If you were never born, how could you travel back in time in the first place? These types of paradoxes violate the principle of causality, which is a fundamental concept in our understanding of cause and effect.
Furthermore, reversing time, as depicted in movies or literature, is not supported by our current scientific understanding. Time is generally considered to be a unidirectional dimension, flowing forward from the past to the future. While we can measure the passage of time and observe its effects, reversing or manipulating time in a practical sense is not within our capabilities at present.
As for building a time machine, it is currently beyond our technological capabilities based on our understanding of physics. Theoretical concepts like wormholes or manipulating black holes have been proposed in scientific theories, but they remain highly speculative and require advanced knowledge and technologies that we have yet to develop.
It's important to note that scientific understanding evolves over time, and what may be considered impossible today could be reevaluated in the future. However, as of now, time travel remains in the realm of science fiction rather than a practical scientific possibility.