The statement that time travel is highly improbable rather than impossible typically arises from the current scientific understanding and theories. While it is difficult to make definitive statements about the possibility of time travel, there are several reasons why it is generally considered unlikely based on our current knowledge:
Theoretical Challenges: Time travel poses significant theoretical challenges within the framework of known physics. For example, the laws of causality and paradoxes such as the grandfather paradox (going back in time and preventing your own existence) present logical and conceptual difficulties. These challenges suggest that any form of time travel would require reconciling these paradoxes or the existence of novel physics yet to be discovered.
Conservation of Energy and Entropy: The laws of physics, including conservation of energy and the increase of entropy (a measure of disorder), have implications for time travel. Time travel scenarios often involve reversing or violating these fundamental principles, making them conceptually problematic. The second law of thermodynamics, which states that entropy tends to increase over time, is particularly relevant as it implies a preferred direction of time, making backwards time travel seemingly incompatible.
Lack of Empirical Evidence: Despite significant scientific advancements and investigations, no empirical evidence or observations of time travel have been documented. The absence of such evidence further contributes to the perception that time travel is highly improbable.
However, it's important to note that our current understanding of physics is not complete, and future scientific breakthroughs could potentially unveil new principles or possibilities regarding time travel. Speculations and hypothetical scenarios within the realms of speculative physics, such as wormholes or advanced theories like general relativity and quantum mechanics, continue to be explored to understand the nature of time and its potential manipulations.
In summary, the notion that time travel is highly improbable is rooted in our current scientific understanding and the numerous conceptual and theoretical challenges associated with it. The laws of physics, particularly those related to causality, conservation, and entropy, present significant obstacles to the feasibility of time travel as commonly envisioned. However, as science progresses, our understanding may evolve, leading to new insights and potential avenues for exploring the concept of time travel.