Regarding the time travel part...
Right now macroscopical quantities of negative energy matter are not available (and in fact are unlikely to exist). Therefore no macroscopic wormholes, rotating cosmic strings and similar.
To have some chance of time travel (apart from the trivial one in the future, time dilatation due to gravity included) you should focus on very small scales, therefore high energy. Apart from the experimental costs (the cheapest thing is probably renting the LHC or looking at cosmic rays!), you will first need a working theory of quantum gravity. And for that it will take a loooong time. String theory is the most mature candidate, and we are only at the beginning.
Still it would be nice to have more research in this field. Good luck!
(Phd in theoretical physics)
Hi!
I'm Sherm77, Minister of Research & Science of WLC & a Transpotimer - I would like to invite you to our slack group:
https://sprnt.slack.com - please visit the 21_tickets channel and also direct message me (sherm77 on slack too) so we can talk about your experience and desire to find the answer to time travel.
Since you are a Phd in Theoretical Physics, I would like to talk and get some guidance on where we should start and ideas that you may have concerning solving the puzzle of time travel. There is much to discover, but we believe that we will solve the puzzle and with the backing of the WLC, we will have everything we need to demonstrate and use time travel in our lifetime. It will be quite a bus ride!
Thanks for your interest and I hope to talk to you very soon!
Sherm77
Minister of Research & Science - WLC
*** Terminator of Impossibilities ***
I'll be back