[JumpCrisscross]

> We absolutely need a world changing type of locomotion one that isn't medieval like the one we use and pride in

We had cryogenic rocket engines in the 60s [1].

[1] https://en.m.wikipedia.org/wiki/Cryogenic_rocket_engine

[klabb3]

I guess liquid is better than gas but any propellant is quite limiting on large spacetime scales.

[Dylan16807]

Let's consider the other options:

Climbing a very good rope. I think this option is the most medieval.

Using a huge launcher brings to mind trebuchets.

An electric plane can give you a higher platform but I'm skeptical of that getting fast enough to be the bulk of a launch.

Antigravity magic? I guess that's not medieval, but I'd argue that magic is in some ways quasi-medieval.

Rockets are likely the least medieval option.

[marcosdumay]

> Rockets are likely the least medieval option.

You mean big explosions targeted at the right side? If the Dark Ages had that, they would be lit!