The hypothetical concept of time travel, even if it were possible, is accompanied by several theoretical and practical challenges that make it unlikely to be a means for "fixing" everything or altering events in a straightforward manner. Some of the main challenges are:
Causality and paradoxes: Time travel often involves the potential for paradoxes, such as the famous grandfather paradox. If someone were to travel back in time and change an event that led to their own existence, it would create a contradiction. Resolving these paradoxes within a consistent framework is a significant challenge.
Consistency and the "butterfly effect": Even small changes made in the past could have vast and unpredictable consequences in the future. This idea, known as the butterfly effect, suggests that minor alterations in the past could cause substantial and unintended changes in the course of history. Attempting to "fix" something could inadvertently lead to even worse outcomes.
Temporal manipulation: The ability to manipulate time could create a range of ethical and practical issues. It raises questions about who would have access to time travel, the potential for abuse or exploitation, and the preservation of the integrity of timelines and personal autonomy.
Energy and technological requirements: The energy and technology required for time travel, as currently imagined, are likely to be beyond our current capabilities. Theoretical concepts such as traversable wormholes or manipulating black holes involve enormous amounts of energy and require exotic forms of matter.
Uncertainty and multiple timelines: Time travel theories often posit the existence of multiple timelines or parallel universes, where changes in the past create separate branches of reality. This would imply that time travel does not actually change our own history but rather creates new timelines, making it challenging to "fix" specific events in our original timeline.
It's important to remember that the possibility of time travel, within the current understanding of physics, remains speculative and theoretical. While it is a fascinating topic to explore in science fiction, the practical implications and feasibility of time travel for altering events or "fixing" everything are highly uncertain and riddled with challenges and paradoxes.