Ok here is my last minute submission... I hope it is not too late! I took this image just an hour ago, fighting the vanishing light before dawn...
You may call it 'conceptual photography' - but I call it showing a sculpture which I set up (within the 'Salzburg International Summer Academy of Fine Arts' 2003, class of Günter Unterburger) to explain the nanometer for public outreach in our physics department.
It is based on - of course - salt! and explained as follows:
You look at this small grain of salt in the loupe - a cube with about 0.5 mm edge length (you can compare the scale paper).
Then you imagine it enlarged so much that the chlorine (or sodium) atoms (which have a distance of 0.4 nm) get the size of pinheads (about 3 mm in distance) which is shown with this cube-corner of plaster made in a replica technique. (One can 'touch' these pinhead-atoms.) - This is an enlargement by a factor of 7,500,000.
How large will then be the grain of salt?
I leave the calculation up to you... But it is no accident that the view goes out into the landscape with a few km distance...
Equipment Used: Linhof Kardan Color, Schneider Super-Angulon 75mm f5.6, a lot of lens and back tilt; Exposure: 5 sec at f32 (the loupe got some additional ilumination with a torch light); Film and Developer: Polaroid T-54, 100 ASA instant b/w film (I also made an exposure on 4x5 TriX film - but for this last minute submission the Polaroid has to be sufficient...)