>>10825950the only sort of multiverse one might be able to travel through is the multiverse of chaotic inflation or string theory. in the string multiverse, the bubble universe we live in is surrounded by something called a "domain wall" and crossing that would typically imply all the standard model particles we are made of spontaneously getting destroyed into something else. so you would need to nucleate a bubble of our string vacuum state until you passed through the domain wall and the noncompact regions beyond it, until you could find your way again through a domain wall into another more hospitable universe. nucleating a standard model vacuum would require some sort of hypothetical technology which would need to cause a macroscopic coherent excitation in the string vacuum that could induce tunneling from one string vacuum state to another, namely our QFT vacuum. this would allow the trans-domain wall travel for some sort of rocket or space ship. however, it is probable that the boundary domain wall of our bubble universe is moving away from us faster than the speed of light, which would mean we need superluminal travel in addition, which would require something like an alcubierre drive, another hypothetical technology that would require bizarre forms of matter that can attain a high density of negative-energy matter, meaning it would have tachyonic properties, which may be allowed in the string spectrum. however, confinement of this sort of stuff might run you into the fact that you'd need such a large hunk of technology that you'd cause a collapse into a black hole, so the engineering might require additional sources of antigravity in addition to the alcubierre drive.
all in all even if all these assumptions were true it would be practically impossible, without tipler-level thinking
