The Living Force
I think this question and answer session with Ra can answer some questions, as it is plainly stated that there are some 3D entities that have learned various techniques to travel long distances. Bolding mine.
51.2 Questioner: Thank you. This next question I feel to be a transient type of question; however, it has been asked me by one whom I have communicated with who has been intensely involved in the UFO portion of the phenomenon. If you deem it too transient or unimportant we’ll skip it, but I have been asked how is it possible for the craft of, shall we say, the fourth-density to get here in that it seems that as you approach the velocity of light mass approaches infinite. We have talked about the increase of spiritual mass and it was just a question as to how this transition from very distant planets is made in craft and my question would be why craft would be necessary at all? This is not an important question.
Ra: I am Ra. You have asked several questions. We shall respond in turn.
Firstly, we agree that this material is transient.
Secondly, those for the most part coming from distant points, as you term them, do not need craft as you know them. The query itself requires understanding which you do not possess. We shall attempt to state what may be stated.
Firstly, there are a few third-density entities who have learned how to use craft to travel between star systems while experiencing the limitations you now understand. However, such entities have learned to use hydrogen in a way different from your understanding now. These entities still take quite long durations of time, as you measure it, to move about. However, these entities are able to use hypothermia to slow the physical and mental complex processes in order to withstand the duration of flight. Those such as are from Sirius are of this type. There are two other types.
One is the type which, coming from fourth, fifth, or sixth density in your own galaxy, has access to a type of energy system which uses the speed of light as a slingshot and thus arrives where it wishes without any perceptible time elapsed in your view.
The other type of experience is that of fourth, fifth, and sixth densities of other galaxies and some within your own galaxy which have learned the necessary disciplines of personality to view the universe as one being and, therefore, are able to proceed from locus to locus by thought alone, materializing the necessary craft, if you will, to enclose the light body of the entity.