Images by Chris Supranowitz of an LP groove (top) and the surface of a CD (bottom), as seen through an electron microsope:
If nothing else, a sure reminder of the various physical realities and resulting metaphors that distinguish the two media: vertical versus horizontal, linear versus random, analog versus digital, gritty versus clinical.
Original post at synthgear.com, found via noiseforairports.com and aaronmeyers.tumblr.com.
Wow, those are beautiful. They really set my imagination going.