@tsarstepan,
Oh one more question who are “they” in they believed this or that?
Somewhere like three thousands years ago in the city of Alexandria the earth circular was measure within a very small margin of error.
The story that in 1491 Columbia needed to convicted anyone that the earth was round is nonsense, in fact he was of the opinion that the earth was a great deal smaller then the Greek measurements had shown it was and therefore his propose journey to Indian by sailing West was possible and he was in fact wrong in that regard.
The earth was the center of the universe was question far and wide for thousands of years and it took all the religion community power to keep the earth in the center as long as it was kept in Europe.
The speed of light is the universal constant to this day and never been question as such by the scientific community no matter how badly you misunderstand theories of wormholes and that the universe in it first birth moments have space expanding faster then light.