The Seiko Think The Earth WN-1 watch is easily one of the most unique watches Seiko has ever made – which says quite a lot, considering Seiko is a watch manufacturer that isn’t afraid to be adventurous (unlike some of its European colleagues, ahem).
 
The WN-1 features a large hemispherical dial, which represents the Earth, under a super-high super-domed Hardlex crystal that rotates once every 24 hours.  Instead of conventional hands, a small silver hook-shaped marker is aligned with your time zone and rotates counterclockwise (just like the Earth itself, mimicking its precise axial rotation) – indicating 24 hours against the bezel – while an orange dot index notes the minutes, giving the wearer a simultaneous sense of global and personal time.  Using the full-recessed crown, the wearer adjusts the hour marker to the correct position.
 
The idea behind the WN-1 was to give the wearer an astronaut’s view of the Earth from space, to encourage people to contemplate issues that affect the planet – like climate change – and relate to the Earth in their everyday lives.  However naive this sounds, it’s inevitable Earth comes to mind when looking, even if it’s only a glance, at the 3D planet on the wrist.
 
A joint project between Seiko and the Think the Earth Project, a Japanese non-profit organization that promotes Earth awareness and sustainability, the concept of an Earth Watch was conceived in 1994, with the first working prototype arriving in 1997.  Shortly thereafter, Seiko Instruments joined the project, and after another three years the official launch followed on February 19th, 2001 – rendering the example here one of the first made.
 
Why February 19th?  The date was chosen on purpose, the birthday of famed Polish astronomer Nicolaus Copernicus – the first to suggest the sun was at the center of the universe and the Earth revolved around it.
 
The WN-1 titanium case has two small holes on the side, at the noon and nine o’clock positions.  A similar hole is present on the bezel, which – when in the locked position – aligns with the hole at the 12 o’clock position on the case.  When the bezel is twisted counterclockwise to match up with the nine o’clock case hole, the bezel is unlocked and can be removed, allowing access to the central module to easily change the time via the now accessible crown. 
 
An interesting facet of the Think The Earth watch?  Once the central module has been removed from the case, the three, six, nine, and 12 o’clock hour indicators are readily apparent, allowing the central module to be used as a standalone clock.  
 
Another fun fact?  Seiko Think The Earth literature notes that, “the diameter of the Earth-dial is 1/580 millionth that of Earth, a scale at which arm’s length (approximately 65 cm) equals 380,000 km.” As such, if the wearer stretches their arm with the watch on, the WN-1 will look incredibly similar to the view of Earth from the Moon.
 
Setting the Think The Earth Watch
There are 24 settings according to 24 world time zones.  To set the correct time zone, one aligns the silver hook marker to their current geographic position.  Once done, the hour indicator rotates counterclockwise together with the model of the Earth.  To read the time, follow the straight line from the North Pole to the bezel and right through the hour marker.
 
Per Fratello, “Strangely enough, the orange 'minute dot' that reminds me of a ping-pong ball rotates clockwise like on an ordinary watch.  One would think that hands running in different directions would mess with your brain too much and leave you confused.  But to my greatest surprise, the \transition was smooth and easy.  After just a few turns of my head to my wrist, I was able to read the time quickly and precisely.  It’s actually so natural that after a week on the wrist, I asked myself, ‘Why isn’t it like this on all watches?’”
 
This Seiko WN-1 comes on its original Sophista strap, and with nylon strap, springbar tool, and rugged travel case.