The possibility of time travel, especially to the past, remains a topic of speculation and debate in the scientific community. While it is challenging to predict the future advancements of science and technology, it is important to understand the current understanding and limitations.
As of now, there is no scientific evidence or widely accepted theory that supports the existence of practical time travel. The concept of time travel to the past is particularly problematic due to the inherent paradoxes and logical inconsistencies it raises, such as the grandfather paradox mentioned earlier.
The idea of needing a machine at both ends of the time spectrum, commonly referred to as a "time machine," is often explored in science fiction. However, constructing a practical and functioning time machine is purely speculative and not supported by our current understanding of physics.
It is worth noting that scientific knowledge and technological advancements can evolve over time. Theories may be revised, and new discoveries may change our understanding of the universe. As science progresses, it is possible that our understanding of time and the possibilities surrounding it may also evolve. However, at present, time travel beyond the realm of speculation and science fiction remains highly uncertain.