1. time travel - Noun
2. time travel - Verb
(chiefly science fiction) Hypothetical or fictional travel to the past or the future, typically by means of a machine (a time machine) or a wormhole.
(databases) The ability to access previous states of a database.
time-travel (uncountable)
Alternative spelling of time travel
(intransitive) To travel through time.
(slang) To sleep.
Source: en.wiktionary.orgtime-travel
If time travel is possible, where are the tourists from the future? Stephen Hawking
Time travel may be achieved one day, or it may not. But if it is, it should not require any fundamental change in world-view, at least for those who broadly share the world view I am presenting in this book. David Deutsch
The bottom line is that time travel is allowed by the laws of physics. Brian Greene
One must stand stiller than still. On reverse time travel. James Jeans
Time travel destabilizes history. History is a child of contingency; so many events depend on critical misunderstandings or transient encounters that even the apocryphal butterfly's wing is apt to stir up a storm in short order. Charles Stross
I myself believe that there will one day be time travel because when we find that something isn't forbidden by the over-arching laws of physics we usually eventually find a technological way of doing it. David Deutsch