I've never seen a glass sphere this large - it's almost surreal: https://en.wikipedia.org/wiki/Campbell%E2%80%93Stokes_record...

I keep looking at it, my brain confused why I can't see through what is clearly a transparent object. It doesn't feel like I'm looking through it, though inverted; it feels like I'm seeing a weird depiction of the nature scene around me plastered on its surface.