The distances are too great they’re not folding space yet the spice is not been discovered. So I’m going to say they are traveling in the fourth dimension from the future of this Earth or maybe from the past.
Science fiction writers have been all over this for the last 50 years.
“Science fiction writers have been all over this for the last 50 years.”
Whistleblowers have been all over the wormhole/portal technology for a couple of decades.
If you are willing to listen to what they have to say here it is:
https://www.youtube.com/watch?v=t564HRXeS6o