Perceived affordances: Bridging innovation and usability

Can you describe the function of the object pictured below?

Internally lit orb with ramp
From A Plunge Into Space by Robert Cromie (1890)

While viewers may differ on the specifics, they tend to arrive at roughly the same conclusion: it’s a structure that houses humans.

Now what about this one?

Large flat machine
From Tom Corbett Space Cadet: The Space Pioneers by Carey Rockwell (1953)

Giant scale? Portable stage? Simultaneous-play DDR dance pad for a 30-person troupe? It’s much more difficult to tell what this object is actually meant to do.

Both of these images depict highly fantastic, imagined objects conceived for science fiction literature over fifty years ago. Neither strongly resembles anything we use today. So why is it that one object (the older one, no less) communicates a clear function to viewers, whereas the other remains ambiguous? The answer tells us a lot about how to create designs that are both innovative yet usable.