Could future humans return to the past?

A serious skeptical reading argues that backward time travel is not merely technologically difficult but conceptually or physically incoherent. It emphasizes the improbable coincidences required for a single consistent past, the possibility that preserving the past while changing the present is logically inconsistent, and the absence of visitors. These arguments challenge feasibility but do not settle the physics conclusively.

• Some analyses argue that classic backward-time-travel scenarios are extremely improbable because records and dispositions would need to align through remarkable coincidences.
• One published argument claims that the assumption that zero change to the past implies zero change to the present is logically inconsistent, making past travel pseudoscientific.
• A philosophical position holds that travelers to the past cannot do otherwise than what they in fact do, limiting their ability to alter events.
• The absence of visitors could be interpreted as evidence against time travel, although another analysis attributes it to energy costs and the low value of information from our era to future civilizations.