To elaborate, by looking
at the properties of those dots on the
surface and how curved lines and
angles behave as the balloon expands, we can distinguish its
surface from that of a flat piece of paper, without needing to think about any
higher dimensions.
Light waves can be reflected / scattered, absorbed, refracted, or transmitted to pass through matter unchanged and different materials will have different effects in these encounters;
high energy light waves get scattered in our atmosphere from encounters with dust, water vapour, molecules, etc. as the white light hits the rough
surface composed of these, so we have a blue sky for example, while the longer IR gets absorbed by water and earth, on a smooth
surface such as glass or still water these
high energy lights get reflected,
angle of incidence equal to, and some pass through to get reflected or scattered
at the next
surface, think rainbow.