The scenario you describe involves a time loop or a "bootstrap paradox," a concept frequently explored in science fiction. In a bootstrap paradox, an object or information exists without having a clear origin or cause, creating a loop where it appears to be self-created and independent of any initial source. Let's break down the situation you described:
Person from the future (Future Person) comes back in time: Future Person arrives in the past and shares information about a person from their past who traveled back in time to inform them about people from their future.
Person from the past (Past Person) comes back in time: As per Future Person's information, Past Person now comes back in time to tell the people from the past (who include Future Person) about people from their future.
A loop is created: This creates an infinite loop where information about people from the future keeps getting passed back and forth through time without a clear beginning or end.
In such a situation, there is no clear origin for the information about people from the future, and it appears to be self-generating. This concept challenges traditional ideas of cause and effect and raises intriguing questions about the nature of time and its continuity.
However, it's important to note that time travel remains a theoretical concept, and no scientific evidence supports the possibility of traveling back in time. The idea of time loops, while fascinating, falls within the realm of speculative fiction and theoretical physics. As our understanding of physics and the universe advances, time travel might remain a captivating concept, but its realization, if possible at all, would likely be governed by complex and unknown principles.