i heard that same thing(courtesy of tool) and it was kinda creepy because he was like what you think as angels are really energetic beings. (i could go many places with that statement) and it didnt send my bull meter off.
now i dont know about you but i believe travel is possible.
since we all on the same place (universe, multi-verse?) different levels of existence. they must be on a different frequency or vibration then us. im to outa of it to remember all of my theory but id like to discuss this more if your willing to get more radical.

on a side note another reason i think interdimensional is they send probes and supposedly* people farther and farther into space but find nothing.
if they can barely perceive psychic or thought energy which the universe is supposed to made of. how could they hope to use a pure science type gizmo, with no metaphysical/quantum science attached and hope to find something?