well, there is no theorizing required - for the sun/moon/stars are observed to be traversing over the face of the earth - that is what everyone observes in the first place -
the only theorizing required is to attempt to negate what we all observe/sense in the first place.
heliocentrism "inverts" observable & sensible to unobservable & nonsensible.
there is old saying from the so-called "age of enlightenment" -
"Newton gained his fame & the people Lost their Senses"
you do realize that is a theoretical explanation - furthermore, inside a train & outside a train are 2 different things - we are outside on the "train/earth" - not inside a sealed container.
Just because we're on the outside of the pod doesn't mean we can magically see the movement, how about we switch to the perspective of a person riding the pod, they're on the outside and observe the pod to be unmoving, with everything moving around the pod.