If someone traveled through space-time and met their past self, proving their identity could be a complex and challenging task. Here are a few potential approaches they could consider:
Personal knowledge: The time traveler could demonstrate detailed knowledge about the past self's personal life, experiences, memories, and events that only they would know. This could include specific conversations, significant life events, or even private information that only the past self would be aware of.
Future knowledge: The time traveler could share specific information about future events or technological advancements that have not yet occurred from the perspective of the past self. By accurately predicting or describing these future events, they could establish their credibility as a legitimate time traveler.
Physical evidence: The time traveler might possess or provide physical evidence that only they could have, such as personal belongings, photographs, or documents from the future that are not accessible to anyone else in the present time. This evidence would need to be verifiable and convincingly demonstrate a connection to the future.
Verification through trusted individuals: If the time traveler had personal relationships with individuals who knew both their past self and their future self, they could involve those trusted individuals to vouch for their identity. These individuals could confirm the time traveler's existence and validate their claims.
Authentication through advanced technology: Depending on the capabilities of the time travel method or the technology available to the time traveler, they might have access to advanced devices or technologies that could provide proof of their identity. For example, they could possess a device capable of analyzing their DNA or biometric data, which would match the information of their past self.
It's important to note that time travel is purely speculative at this point, and we don't have any confirmed scientific evidence or methods to support it. The concept of meeting one's past self raises numerous paradoxes and challenges, making it difficult to provide definitive answers.