Sorry guyz my question was not clear. In other movies like Star Wars, Star Trek and similar movies where they travel at light speed or more than that, those movies never showed any kind of force exerted on the astronauts. They just jump to hyperspeed/warpspeed and come to halt their ships easily without any affects on their bodies. In Expanse, light speed technology was not mentioned but those ships did have some high speed technology, may be lesser than light speed. While the ships move at such speeds a force was applied on the people traveling in it and a white liquid was injected in their bodies to keep them awake. My question is If there is no gravity in space then how come humans felt a force which made them to pass out like Chrisjen Avasarala passed out when she traveled in Razorback ship. Does fast moving space ships in space affect humans and hence a liquid was used to keep them awake. I need this theory to be answered. Hope you are able to understand me now.
My original question for reference: In The Expanse series it was shown that the people inside Rosinate and Razorback had to be injected with some liquid in order to stay awake during the ship travelled at a higher speed than usual. Why was that liquid needed if space doesn't exert any force on human body. Please can you explain what kind of force was affecting the people travelling in space in these series. I also want to know if that was due to the artificial gravity that the ships produced.