What would happen if the energy from the sun was not reflected back

well, It would have an effect very much like over inflating a balloon. The space inside the Dyson Sphere would be overfilled with energy and the Sphere would be assaulted by energy that exceeds it's capacity to reflect it.

Explanation:

qualitative observation deals with data that can be observed with our senses: sight, smell, touch, taste, and hearing. they do not involve measurements or numbers. for instance, colors, shapes, and textures of objects are all qualitative observations.

alchemy hadn't scientific methods of study, appeal to mysticism and fantasy, the knowledge of chemistry and physics were modest at that time.

alchemy was - but as new rules were discovered it either changed into chemistry or it became "unscientific".