High School Another doubt I had while reading Feynman Lectures

[Rishabh Narula]

"The “stage” on which the universe goes is
the three-dimensional space of geometry, as
described by Euclid, and things change in a
medium called time."
-Feynman Lectures
Do the 1st two lines mean that the thing
in which everything moves around is
the 3 dimensional space...am i interpreting
it right?

 

[HallsofIvy]

Yes, that is exactly what it says.