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time travel. introduction. External time is the ordering of events as given by an objective historian. Personal time is the ordering of events as experienced by a particular individual. A time traveler is someone whose personal time diverges from external time . definitions.
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time travel introduction
External time is the ordering of events as given by an objective historian. • Personal time is the ordering of events as experienced by a particular individual. • A time traveleris someone whose personal time diverges from external time. definitions
A state of affairs is practically possibleiff it is consistent with our abilities. • A state of affairs is physically possible iff it is consistent with the laws of pyhsics. • A state of affairs is metaphysically possibleiff it is consistent with the laws of metaphysics. • A state of affairs is logically possibleiff it is consistent with the laws of logic. definitions
In one minute, we will have traveled into the future. • If (1), then time travel is possible. • [So] Time travel is possible. the simple argument
It is possible to travel from eastern Kentucky to western Kentucky in under an hour. • If (1), then time travel is possible. • [So] Time travel is possible. the time zone argument
We know that humans (homo sapiens) first appeared about 2 million years ago. • If (1), then we know that no humans appeared in the Jurassic period. • If we know that no humans appeared in the Jurassic period, then we know that time travel is impossible. • [So] [We know that] Time travel is impossible. the anthropogenisis argument
There have never been any reports of time travelers appearing throughout human history. • If (1) then time travel is probably impossible. • [So] Time travel is probably impossible. the “noseeum” argument