People need to crack open their bible. There are no aliens from far away. The maneuvers they make would kill them. It would take generations just to get here.
Not unless they’re multidimensional.
Wormholes. Or The spice (Melange) is vital to space travel. The Spacing Guild and its navigators, who the spice has mutated over 4000 years, use the orange spice gas, which gives them the ability to fold space. That is, travel to any part of the universe without moving. Because the Guild controls all interplanetary travel, they are the highest power in the Universe.
The maneuvers they make would kill them. It would take generations just to get here.
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With our current technology, yes. We can’t reasonably travel interstellar distances.
But consider how far our technology has advanced from say 500 years ago. Imagine showing someone from 1500 A.D. a mobile phone or an airplane. They would consider these things to be impossible. Now imagine some alien world where their tech is 500, a 1000 or 10,000 years more advanced than our own. To us it would look impossible.