Any ideas on how to create a time travel device?
I embrace the notion that a higher level, way more advanced civilization, could accomplish, "Perceived Time Travel" on local scales. Like a Kardashev level 3, 4, 5+. Simply, it would resemble rewinding a VHS, or dvd, and replaying it forward. ***Warning*** I have non mainstream thoughts often, this response is one of them.
Two things are essential to do this:
1) The complete information of a local system. Every atom, down to the quantum level (or further), every neuron...all information as it relates to the system.
2) The ability to arrange every atom...every neuron at will. In today's society IBM has managed to re-position individual atoms. We are far from doing all that is needed but a high level Kardashev may not be...somewhere in the universe.
Having all the system information and ability to manipulate could allow a system to be re-arranged to an earlier time. A system could be our local solar system, our galaxy, our super cluster, etc. It would be like reversing a movie and playing it forward again...rearward time travel as perceived, locally, to those observers.
Similar to Einstein's Equivalence Principle (gravity/ acceleration being indistinguishable from eachother), the reversed system would be indistinguishable from the system that was reversed to that point...again, at least locally to all internal observers of that system.
I understand the idea is almost psuedo science. It does require believing in an advanced entity or civilization who is super advanced. The OP did not have limitations set in the question (like, "How could mankind create a time travel device, etc) so I respectfully request that my answer not be, "kicked to the curb" to hastily. I am just "thinking outside the box", lol...way outside:)