The technical reason is that light loses some of its energy each time it bounces (i.e., some of the light gets absorbed by the mirror and the air in the box).
(it; bounces; T:each time) (some of the light; gets; absorbed by the mirror and the air in the box; T:each time it bounces) (The technical reason; is; that light loses some of its energy each time it bounces (i.e., some of the light gets absorbed by the mirror and the air in the box)) Context(The technical reason is,List([0, 23))):(light; loses; some of its energy; T:each time it bounces)
The technical reason is,List([0, 23))
it some of the light The technical reason light
bounces gets is loses
T:each time
absorbed by the mirror and the air in the box T:each time it bounces
that light loses some of its energy each time it bounces (i.e., some of the light gets absorbed by the mirror and the air in the box)
some of its energy T:each time it bounces