While we're talking about how fiction messes up space travel.

I did the math a couple hours ago on the current Marvel Comics Timeline. Currently, it was only a few weeks between the Absolute Carnage Event, which ended with Knull, God of the Symbiotes, being from his prison at the core of planet Klyntar and King in Black, which begins with Knull and his armies arriving at on Earth.

Klyntar was located in the Andromeda galaxy, which is over 2,500,000 lightyears away from Earth. Not even counting the distance from Klyntar to the edge of Andromeda and giving a very generous four-week time span, this means that Knull and his forces would have to be able to fly through the vacuum of space at 32,589,285.725 times the speed of light.

This is, of course, the bare minimum. It was probably less time, and we know he took at least one detour.

This honestly wouldn't be so bad by comic book standards... Except they don't use ships. They flap their wings, becuase they're dragons.