Temporal paradox
A temporal paradox, is a time paradox, or time travel paradox. It is a paradox, or logical contradiction, of time and time travel.
Temporal paradoxes fall into two broad groups. Consistency paradoxes (example: the grandfather paradox) and causal loops.[1]
A causal loop is a paradox of time travel. It occurs when a future event is the cause of a past event, which in turn is the cause of the future event. Both events then exist in spacetime, but their origin cannot be known.[1][2][3][4]
Other paradoxes of time travel are a variation of the Fermi paradox,[5] and paradoxes of free will that stem from causal loops such as Newcomb's paradox.[6]
Not a paradox
Fermi's so-called paradox is not a paradox, just a question. It does not involve logic, just the practical (empirical) fact that stellar distances are so great, and our ability to collect data from other bodies is limited.
Temporal Paradox Media
Top: original billiard ball trajectory. Middle: the billiard ball emerges from the future, and delivers its past self a strike that averts the past ball from entering the time machine. Bottom: The billiard ball never enters the time machine, giving rise to the paradox, putting into question how its older self could ever emerge from the time machine and divert its course.
References
- ↑ 1.0 1.1 Francisco Lobo (2003). "Time, closed timelike curves and causality". Nato Sci.ser.ii. 95: 289–296. arXiv:gr-qc/0206078. Bibcode:2003ntgp.conf..289L.
- ↑ Nicholas J.J. Smith (2013). "Time Travel". Stanford Encyclopedia of Philosophy.
- ↑ Leora Morgenstern (2010), Foundations of a formal theory of time travel (PDF), p. 6, retrieved November 2, 2015
- ↑ Klosterman, Chuck (2009). Eating the Dinosaur (1st Scribner hardcover ed.). New York: Scribner. p. 60. ISBN 9781439168486. Retrieved 2 February 2013.
- ↑ Fermi paradox: not really a paradox, just a question: see link.
- ↑ Jan Faye (2015), "Backward causation", Stanford Encyclopedia of Philosophy, retrieved May 25, 2019