1/2 Notes on #UAP Discussions : From the standpoint of #Physics #Interstellar travel via physical craft with reasonable transit times for both craft and passengers invokes a relativistic firewall involving craft mass and required energy densities at significant fractions of the speed of light.Advanced knowledge of #Spacetime dynamics and topologies are one way through that firewall. Two stages of development invoke what are locally or globally #Interdimensional technologies for warping-