Solar System in a Watch: Why the Casio cosmophase is an important milestone in horology

In need of a perspective shift and a reconnection back into where we really sit in the cosmos?

Want access to millennia of accumulated human knowledge on celestial movements previously only available to the highest of high horology within an 80s casio digital watch?

Just want to impress your friends with a cool demo of planets whizzing round on your retro watch?

Wherever you are on this spectrum - the Casio Cosmophase has got you covered.

This post will show some history behind how we began to mechanise our understanding of the cosmos into instruments over time and how things evolved such that in 1989 casio were able to provide us with this beauty of a watch - now so sought after amongst collectors alongside its cousin the moon graph - and perhaps the twin graph.

First phase of our journey reminds us how ingrained the observation of the skies has been back to our earliest civilisation:

Cataloguing of celestial movements by ancient civilisations

There was cataloguing of the sun, moon and stars by ancient civilisations. The Sumerian and Babylonians have artefacts showing this was the case from at least 6000BC and there are records of mammoth tusks that have astrological inscriptions. The Egyptian pyramids are believed to be linked to the Sun god through their alignment, with the use of monuments that have a relationship to celestial bodies also being likely with Stone Henge - perhaps in a similar way to todays Manhattan-henge phenomenon.

The solstices - that is the shortest and longest days, and the equinoxes - i.e. when the sun is directly above the equator and the days and night are equal - are obvious events within the year that had meaning for many civilisations even before we had a proper framework for time. In many ways this stuff predates horology - which is saying something!

Within the Indian sub continent Lagadha Maharishi of Mehrgarh made texts documenting the sun and moon movements, as well as Aryabhata - the inspiration behind the naming of Indias first satellite into space. Ancient China had many astronomical observations too with the first known record of a solar eclipse in 1217 BC being on a bone inscription, as well as a likely sighting of what would be Halley’s Comet in 611 BC. The Mayans in AD 250-900 apparently wrote extensively about the sun and planets and stars - as well as their famous prediction about the end of the world on 21st December 2012. And the Aztecs and Incas were also keen observers of the skies with their Sun God - with the Aztecs also being interested in Venus - seen as being the god quetzacotl.

I say all this - as its important to understand that it is not just in the western tradition that such things were being considered. But of course, where would we be without the Greeks and Romans?

Greeks and Romans

Geocentric and ptolomeic representations of the cosmos with the earth at the centre of things go way back. These typically include the so-called wandering stars i.e. the planets sun and moon being in concentric spheres around the earth , with the fixed stars i.e. with the signs of the zodiac and the firmament - being one of the outer layers - with the primo mobile being the master layer beyond that to which everything is fixed moving in nice circular orbits - with some fancy additional crystalline spheres being added by some and empyreal heavens added by Christians.

There were a few folks that posited the possibility that planets may revolve around the sun - like Aristarchus of Samos according to the work of Archimedes - but Geocentrism would be the order of the day for quite a while. There was a decent amount of flat earthism from the Greeks pre-Pyhthagorus - but to be fair to them, one of them - Anaxagoras - has been credited with identifying the mechanisms behind solar and lunar eclipses i.e. that the moons light is light reflected from the sun .

Mercury the closest of the so-called terrestrial planets is obviously the Romanisation of the god Hermes - which is what the Greeks called Mercury due to it being fleet footed like the messenger god with its short time to make a complete revolution - seemingly around the earth - although they did mix up with Apollo - god of the sun when it was more proximate to the sun.

Because of its brightness in the sky the Greeks would call what is now Venus - Aphrodite - due to its bright beauty - a notion I think they would have been disabused of if they actually knew the hell like landscape of the real Venus!

Mars had red colouration like blood so was named Ares by the Greeks after their god of war

Jupiter - the first of the gas giants as you move out from earth was named Zeus by the Greeks- obviously boss of the Gods and godfather of the planets. Did you know that it had blue poles as well as the yellow and orange image we all had as kids?

Saturn was named Cronus a named linked with chrono with obvious time connotations with chronograph, chronometer and such. Saturn - the romanisation is more linked to be saturated due to eating his children - and a sense perhaps that time feasts upon the ages. An interesting way of looking at things right!

Initial Mechanical Portrayals

But what about translating all this into mechanical objects that could predict such movements? Well the truly unbelievable 150-100 BC Antikythera mechanism is believed to be an analogue computer used to calculate the position of the sun and moon and perhaps the planets. It has signs of the zodiac on the dials and apparently takes leap years into account as well as prediction of lunar and solar eclipses. Pretty mad!

Armillary spheres - a representation of the principal celestial spheres - were likely used by the Ancient Greeks - Eratosthenes being thought to have likely used one - Chinese, Islamic and even renaissance scholars to try and coordinate the positions of different celestial bodies.

Astrolabes are a flat model of the stars and planets which Theon of Alexandria wrote about and we have surviving examples from AD 927 - with Islamic scholars also writing on this topic , as well as Chaucer of Canterbury Tales fame.

The earliest escapement clock - which also amazingly has significant astronomical elements - is the Richard of Wallingford clock of St Albans abbey. This is a replica of this clock that you can go and see in St Albans cathedral today.

Giovanni de dondi’s astrarium clock is another really complex clock that indicates movements of celestial objects and events with 7 dials.

Cathedral astronomical clocks were amongst the earliest mechanical clocks with many examples in England and this example from Prague

The astronomical clock of Hampton court is an example of a clock that also included sun position, sign of the zodiac and moon phase. Note that this is heliocentric with the earth at the middle.

This of course brings up the critical topic of the evolution of earth centric view of the solar system to a sun centric or heliocentric view.

Geocentrism -> Heliocentrism

Some of the original Greek thinking that was almost entirely geocentric apart from a few exceptions would come back to the fore in the west in 1472 after being preserved in places like Constantinople and by Islamic scholars, with one of the first printed scientific books - De Sphaera - which would be fundamental reading for the first english astronomer royal John Flamsteed - and another influential polish or Prussian guy Nicholas Copernicus. However, going against this view of things, he would publish his De Revolutionibus Orbium Celestium (on the revolutions of the heavenly spheres) in 1543 which heavily implied that heliocentrism made more sense, although it would take a long time before these would become accepted due to suppression on religious grounds so the dominant view would continue to be geocentric.

Tycho Brae in 1577 realised that the idea of fixed heavenly spheres was sketchy when he observed a comet that was beyond the moon. Such things had been explained away before because they were sub-lunar and not part of the heavens. He arrived at a slightly weird view of things though called a geoheliocentric view where the sun, moon and fixed stars revolved around the earth, but all the other planets revolved around the sun .

Johannes Keppler was the next important step in evolving the view of the cosmos in 1609 Astronomia Nova’s conclusion that the planets had elliptical orbits rather than perfect circular ones with the sun in one half of the centre of the inner elipse.

This creates a situation where on one half of the orbit you are at a point where there is a particular closeness to the sun, and one half of the orbit where you are furthest away - the perihelion and aphelion respectively. You’d think this would have related to the seasons but all that is actually related to the tilt of the hemispheres of the planet and the focus of the sun - i.e. where it is directly overheard - moving between the Tropic of Cancer in the north and Tropic of Capricorn in the south.

The transit of Venus is when Venus is between the sun and a planet on the outside of it - a superior planet - when all sorts of tilting factors line up - which from earth can be seen as a black disc going across the sun.

Keppler would be one of the first confirmed people to predict a transit of Venus, but it was Jeremiah HOrrocks in 1639 who actually observed one.

Of course - Galileo Galileo started using his telescope - also in 1609 - with his discovery of Jupiters moons showing that objects in the heavens revolved around things other just the sun and the earth and that there are more celestial bodies out there that we didn’t know about. He published about this in his book siderius nuncius - the starry messenger.

The “naked eye” wandering stars of Sun, Moon, Mercury, Venus, Mars, Jupiter and Saturn were known about from ancient times although they were just lights in the sky. But Galileos work uncovered 4 of jupiters moons - io , Europa, Ganymede , and Callisto.

If you want your mind to be blown look in to the current understanding of Jupiters hypothesised mission towards the sun during the early formation of the solar system that caused all sorts of destruction, but is also credited with likely causing the conditions that made it possible for Earth to be how it is - before moving back again and being somewhat of a protector of the inner solar system with its ridiculous gravity keeping the keiper belt in check, with the occasional lapse allowing the odd apolcyptic celestial body to charge towards the sun - as they think was the case with the dinosaur stuff.

In 1655 Christian Huygens solved part of the riddle of Saturn - that is that it had rings after this had confused Galileo and others - as well as its largest moon titan. We obviously know that Saturn has a whole bunch of moons, as well as one that is currently one of the leading candidates for the possibility of alien life - Enceladus - after insights from the amazing Cassini mission.

In 1705 Edmund Halley published his work which included a comet that would reappear around every 76 years - which would later bare his name but had been seen by others before him.

So we’re starting to bottom out at a recognisable view of the solar system with elliptical orbits, the naked eye planets and some moons coming into play. So how did we start mechanising all this?

Tellurium’s -> Orreries

Early examples of model makers are Richard of Cumberland who had made a planetarium in the early 1700s and Stephen Hales is also said to have made a model of the sun moon and earth around this time. But George Graham was the real master of these mechanical models with one around 1710 later referred to as a proto-orrery as it did not yet include planets beyond earth. It is likely one of his, or a similar model, that was made under the patronage of the fourth early of orrery Charles Boyle - which is why they are called orreries.

John Rowley built orreries for the earl of orrery , but also produced orreries for Charles VI , Peter the Great and the East India Company. His original orrery was restored by Rupert Thomas Gould who is the same guy who famously restored the John Harrison Marine Chronometers. The Jesse Ramsden Orrery is another famous example, as well as Benjamin Martin in 1764 and WIlliam Jones around 1800. When you combine clocks with orreries you get astronomical clocks. Such as this amazing one made by Henry Jenkins in 1778. This is the first phase of mechanical models of the solar system - but things were evolving in our understanding of the solar system.

Later solar system discoveries

The planet Uranus would come into the fray - discovered in 1781 by William Herschel - later discovered to have 7 rings and lots of moons. Neptune was the next planet that had previously not been seen with the naked eye - and was identified in 1846. Pluto would join the list in 1930 before it was sadly downgraded to a dwarf planet in 2006. This is probably fair enough once you learn how many dwarf planets are known about in the system. You’ll be waiting a while for these guys to orbit around the sun as Neptune takes 165 years and Pluto takes a nice 248 years - so even the Casio Cosmophase’s 300 year window will only get one orbit! So things are settling around our 9 planet solar heliocentric solar system model with elliptical orbits - before poor plutos demise - so how were we starting to integrate this insight into wrist watches?

Getting into watches

There are many different variants of so called astronomical complication - and these have their own histories that pre-date their use in watches, but if we stick to watches patek Phillip developed the first moon wrist phase watch in 1925 with other famous example being the 1949 Rolex 8171.

Of course, watches and pocket watches that combined consideration of the signs of the zodiac and moon phase were available pre 1900 such as this example from the British Museum

Sun and moon dials like the modern classic orient model are more straight forward and essentially are decorative.

Constellation focused watches are another category of cool watches - Citizen has had watches in this area for a while - including under one of their luxury brands and IWCs Portuguese Siderale Scafusia is very cool.

You can get very mad with astronomical complications - for example the Vacheron Constantin reference 57260 with 57 complications and the wrist watch version Celestia Astronomical Grand Complication 3600.

Patek Philippe had some incredible watches with celestial displays built into more general complication craziness like the Packard watch and the Bovet Grand recital is also very impressive.

There are even earth focused astronomical watches such as the Ulysses Nardin Tellerium Johannes Keppler.

But back to portrayal of the solar system in a watch. Christian Van Der Klaauw is one of the leading guys pushing the more recent utilisation of astronomical complications into clocks and watches. For example his 1974 astronomical clock set a path that would lead up to his 1999 CVDK plateterium - apparently the worlds smallest planetarium and would go on to continue with watches in this vein.

Ulysses Nardin had the Astrolabium in 1985 and in 1988 would release the 1988 planetarium-nicolaus-copernicus.

Van Cleef Arpels do a cool planetarium watch - worn by Matt Damon on the red carpet during his Martian phase

Geo. Graham Orrery Tourbillon links back to the history of the orrery with its name

And of course - there is the ridiculously elaborate Jacob and Co Astronomia which Producer Michael is a fan of - but gets a decent amount of abuse elsewhere.

Note that is pretty much the highest of the high horology that have been in the game of mechanical planetarium watches. How could these features be made more accessible to us normal-ish people?

Electronic data on planetary positions and the arrival of the Casio Cosmophase

There is some very precise data going backwards and projected forwards on the estimated positions of the planets which can be easily preset into a database and subsequently a watch linked to specific days and dates.

Casio had been in the business of presetting things out for a long time - Data banks had calendars going until 2099 from the early 80s.

Presetting backward and forward dates could be seen with the universal calendar model where a monthly calendar could be displayed from 1901 to 2099

A go to source for planetary positions is NASA;s Jet propulsion laboratory or JPL at the California Institute of Technology’s Solar System Dynamics group via its Horizons service which launched in October 1996. This data feeds a lot of the online resources you see today regarding the position of the planets. The Parisian Bureau of Longitudes is also another group focused on very precise understanding of the positionings of objects within the solar system with this work being done now by the The Institute of Celestial Mechanics and Ephemeris Calculation. The US Naval Observatory has its own very detailed data on solar system objects. The go to guide for computer modellers of the solar system would come out in 1991 - two years after the launch of the cosmo-phase Jean Meeus’s Astronomical Algorithms - which is the base for other methods still used today like PyEphem. Of course Japan has its own Ephemeris computation office within the National Astronimcal Observatory of Japan which publishes the calendar and ephemeris almanac. From digging it looks like the Japanese ephemeris calculations going way back were very similar to those in the British Alamanac in 1948.

Annoyingly the casio manual doesn’t list its source for planetary positions used in the cosmophase module so it could be almanacs of any of the above, or previous iterations of Jean Meeus’s work that was less modernised. But there are multiple different sources that they could have used.

Around April 1989 Casio Launched the Cosmo Phase CGW-50 with module 830 within its wrist instruments range along side the moon graph, fish en time with tidal display , map meter , thermometer, tri graph, digi graph and barometer. The other models would be pre-programmed to 2029 with their calendars , but the Cosmophase would go a little further and go to 2200!

Using the same module in the range we would see CGW-500, the CGW-501, the CGW-91 and the DW3400. I’ve seen it in casio catalogs up to to 1994 and they aren’t there in 1997 so unsure as to their status in 95 and 96 if you have those catalogs - send me me pictures and comment below!

The positions of the planets can be interacted with in four cool ways:

1. Of course you can see where the current position of the planets are as per the current date and time

2. You can start a demo of the planets moving by pressing the top left button to activate rapid simulation mode where the sun flashes

3. You can scroll forward or backward between 1901 and 2200

4. Or set a specific date you are interested in

Referencing the Hydrographic department of the Japan Maritime Safety Agency (now the Japan Coast Guard), the key events of Halley;s comet were programmed which are 20th May 1910 ; 27th November 1985 ; 10th April 1986 ; 29th July 2061 ; 7th May 2134 (with the last of these estimated by casio).

For solar eclipses - these were taken from Canon of solar eclipses - Pergamon Press. -first published in 1966. This built on from an original work from 1887 by Theodor von Oppolzer called Canon der Finsternisse (canon of eclipses). The method used originally was an IBM 1620 data processing system located in Ghent Netherlands. Casio have preloaded 200 different solar eclipse dates.

Some fun animations are when the alarm goes of there is a shooting star animation that traverses across both the solar system display and time display - and this also happens on the hour.

For the 4 alarms you can choose to deploy as a daily alarm, monthly alarm, daily alarm for one month period or date alarm for birthdays and such. For the 24hr stopwatch with split lap function - all the planets whiz round in a straight line. For the 24 hr timer alarm - all the planets expand out from the sun. Interestingly there is a feature I’ve not seen featured on other videos which is this auto repeat mode where the timer keeps restarting once its run down. They also do an alarm clock version too - along side their broader series of interesting desk clocks

So what are my thoughts on this watch:

Pros on the rational level:

• Love the dimensions as a member of the small wrist club

• I’m particularly chuffed by owning a stainless steel version in the condition that it is in. Feel like I’m somewhat a custodian of the watch!

• The functionality of the basic features is great - nice day/date and time on the front page with acceptable water resistance and good alarm / hourly chime , stop watch and timer features

• The advanced features are very eccentric and entertaining with fun use of the graphical display on the LCD screen - and inventive use of the display within the other modes.

• Obscurity of the watch within the digital watch sphere - Casio have not re-issued the watch and I’ve not seen any other digital watches with the function. Let me know in the comments if you know any

Cons on the rational level:

• Expensive to get a hold of - particularly for rare iterations and particularly hard to get hold of one in any reasonable condition

• The solar system display is very very small and to be used reasonably I end up using the magnifier on my iphone

On the more emotive level - wearing this watch for a couple of months now on and off - its something that triggers me into thinking about our broader position in the solar system and of course more broadly and I’ve been “looking up” more within the current “don’t look up” global climate which provides a much needed perspective shift. It also brought to mind scenes in Men in Black and Rick and Morty where i started thinking that perhaps there is a whole cosmos actually in there! As you can tell - thinking astronomically can cause a chain reaction into thinking about all sorts of stuff - as we‘ve seen in this post - so its a dose of medicine that I think would be of value to all considering it.