They used to talk about the idea that space is a vacuum and that as such there is no friction to slow down an object once it is set in motion. They talked about how a person might control their flight if they were floating in space. The idea was that a person might fire what was then called a retro rocket. A little blast from a small rocket would slow a person down or alter a person’s course while they were floating in space.

It does not seem possible that a thrust from a rocket would alter a person’s flight path at all. It would if there was an atmosphere or a solid body to push against but in open space there is none. Space is a vacuum after all and even the vibrations that would cause sound in an atmosphere or on a solid body cause no sound in space.

The idea of propulsion in space can’t be thought of in terms of propulsion in an atmosphere or on a solid body. Propulsion by means of thrust can’t work in space. The idea of impulsion might work. Those teachers at that little school so long ago used to talk about that possibility as well. They used to talk about the idea of using ionic propulsion as a means of space travel. The person or the craft is not being pushed by thrust but is being pulled by the intake and the exhaust of the ions in space.

A craft could reach some incredible speeds depending on the density of the ions in the region of space. Some areas of space have more densely concentrated ions than other regions do. The idea of movement through space by means of impulsion would also lead to the theory of travel by the folding of space. The idea of folding space is included in the string theory. I don’t believe that folding space would work the way most people might think.