Two bodies I have,
Though both joined in one
The stiller I stand - The faster I run
This is an old-classic riddle
From The Book of Riddle Portland: Bailey & Noyes.
Are you an:
Hourglass?
Two bodies I have Though both joined into one:
It has a top compartment and a bottom one and is connected.
The stiller I stand - The faster I run
If it is still, the sand runs faster into the other compartment and if it is not still, it is harder for the sand to get into the other side. (kind of a stretch)
Are you
the spacetime continuum?
Explanation:
Space and time are two separate concepts that are both part of the same entity, spacetime. The slower you move through space, the faster you move through time (and vice versa), because of relativity.