Comparing the Prague Calendar-Clock to MONAD

For thousands of years people used Sun dials to tell the time of day, to help them know when to go to market, meet their friends or attend religious services. The shadow cast by the gnomen of a sun dial is like the rotating hand of a clock, but the experience of using a sun dial is much different from using a mechanical clock. On a sun dial, the day time period between sunrise and sunset is divided into 12 hours, and an hour is longer in the summer than it is in the winter.

Mechanical clocks were invented early in the 14th century; they literally ‘ticked’ and ‘tocked’ as the hands moved clockwise in circles around a numbered dial to indicate what ‘time’ it was. These new devices divided time into short, equal units that were easy to use and remember. With a mechanical clock all you need to know is that an hour is the time it takes for the hour hand to move from one number to the next, and an hour is always the same length, no matter what time of year.

Also for thousands of years people would determine what constellations were visible in the night sky in order to tell the time of year or date, to help them know when to plant seeds or start harvesting their crops. Ancient astronomers developed elaborate, Earth-centered celestial spheres and precisely mapped the paths of the Sun and the Moon, the planets and the constellations, and they could predict eclipses, equinoxes and solstices with amazing accuracy. Displaying all this knowledge of the time and date was a matter of great pride to the people who understood it and some cities competed to see who could create the most elaborate celestial calendar-clocks, which were often installed in town squares where everyone could see them and benefit from their information, which was extremely useful for an agrarian or agricultural society where the vast majority of people were involved in farming or gardening, and highly dependent on the rhythms of nature which these calendar-clocks measure–the solar day, lunar month & seasonal year.

Telling the time & date in an Agrarian Society.
Left side: 610 year old Astronomical Calendar-Clock in Prague.
Right side: Brand new MONAD Calendar-Clock app, in your pocket.

One of the most amazing mechanical calendar-clocks that still exists today was constructed in Prague, the capital of what is now the Czeck Republic, in 1410. Our understanding of physics, astronomy and the solar system has advanced incredibly since then and the MONAD Calendar-Clock app presents a modern and much more sophisticated version of the Prague Calendar-Clock, incorporating all of this new scientific information. Before I compare PRAGUE vs. MONAD, let’s take a look back at some of the important discoveries in the past 600 years that have made MONAD possible.

Historical Development Leading To MONAD

Back when The Prague Calendar-Clock was installed (1410), almost everyone still believed that the Earth was fixed at the center of the universe, and the Sun, Moon and Stars rotated at different rates around the fixed Earth. It wasn’t until the year 1543, when Nicolaus Copernicus published On the Revolution of Heavenly Bodies, that Earth was recognized as a spinning planet orbiting a central Sun, which all the other planets also orbited, while only the Moon orbited the Earth. Copernicus replaced Earth at the center with the Sun at the center.

In 1582 the Gregorian calendar was adopted, reducing the average year from 365.25 days to 365.2425 days. In 1584 Giordano Bruno published Of Infinity, The Universe and The World, advocating a Copernican view of the Cosmos, suggesting that all stars have planetary systems. The year 1600, Bruno was burned at the stake for heresy.

In 1609 Johannes Kepler published New Astronomy, where he first describes elliptical orbits and introduced his first two Laws of Planetary Motion. Ten years later he published Harmonies of the World which included his 3rd Law of Planetary Motion, and in 1621 he published Introduction to Copernican Astronomy.

In 1641 Galileo Galilei designed the first pendulum-regulated clock. He died the next year, the same year Isaac Newton was born. By 1660 pendulum-driven clocks were accurate enough to include minute hands. In 1665 Newton invented calculus, and 22 years later he published the most influential physics book ever: Mathematical Principles of Natural Philosophy, which made possible the Industrial Revolution which began 1781 when James Watt improved the steam engine, the first prime mover. Uranus was discovered by William Herschel the same year.

In 1714 Gottfried Leibniz, who invented calculus independently of Newton, wrote The Monadology. In 1780 mean time was made standard in Geneva, and in 1846 Neptune was discovered. In 1884 the Prime Meridian Conference established 24 time zones all around the Earth, and in 1918 the U.S. Government passed the Daylight Savings Act, which still annoys me a bit as it seriously complicated the development of MONAD.

In 1929 the quartz clock was invented, which is accurate (regular) to one millionth of a second. In 1946 the first electronic computer, ENIAC, was completed, and in 1947 John Bardeen, Walter Brattain, and William Shockley invented the transistor, which lead to the modern Computer Revolution. In 1958, Jack Kilby and Robert Noyce, working independently, developed the integrated circuit. The year 1969 was marked by the invention of the internet. The year 1975 the first microchip was invented, and one year later Steve Wozniak and Steve Jobs launched the Apple I, the world’s first personal home computer.

August 27, 2006 was when I first had the idea for the Calendar-Clock. (This was one year before Apple introduced the first touchscreen cellphone (2007) called the iPhone.) At the time I was in the process of writing and illustrating a book: Owner’s Manual, Human Vehicle, which was privately printed December 2012. Even after working on it for 6 years, the Calendar-Clock was not yet fully realized in this book. I had a “Day-Light Provider” (separate from the Sun) illuminating the Earth, which moved back and forth, north and south, on a meridian track fixed at noon. But I still had the background of the stars fixed in my mind with the 24 hour number dial, with the Sun slowly rotating once per year relative to the fixed stars. It wasn’t easy to “fix the Sun at noon,” and most people still don’t really see it when they look at MONAD.

After Owner’s Manual was printed, I decided to focus exclusively on the Calendar-Clock, and shortly after that I realized how to fix the Sun at noon. The year 2014 I published a second book explaining how and why the Calendar-Clock works, called Monadic Space-Time and the Calendar-Clock. The year 2015 I completed the first prototype of a 2 dimensional Calendar-Clock that didn’t yet account for elliptical orbits, and also a 72 second animation showing two years of astronomical activity, with the Sun moving back and forth on a Solar Meridian which also serves as the Date Indicator pointing at the date on the calendar band.

I spent most of 2016 trying to figure out how to build a calendar band reflecting elliptical orbits. After many discussions with my father, Wesley, we were able to work out the basic interaction, which is based on Kepler’s second law of planetary motion which describes the speed of a planet traveling in an elliptical orbit around the Sun. Kepler’s second law states that a line between the Sun and a planet sweeps equal areas in equal times. There are exactly 365.24219 twenty four-hour days in a seasonal year, so if you mark a line on the calendar band indicating the location of the Earth at each midnight, then you generate a series of Day Blocks that form the Calendar-Band for any particular seasonal year.

I started working with my Programmer in 2017 and the first version of the MONAD App, featuring only a 3D Calendar-Clock and two Modes, Helio and Geo, was uploaded to the App Store September 21, 2018. Further programming led to MONAD Stage 2, the Prototype, which was uploaded to the App Store September 31, 2019 and is currently available for download. It features both 2D & 3D Planetary Calendar-Clocks, with four main Modes: Helio, Geo, Astro & Event.

Comparing PRAGUE vs. MONAD.

Now let’s compare some of the features of the Prague Calendar-Clock vs. MONAD. On PRAGUE, the Sun is attached to the hour hand which rotates once per day around the fixed Earth. This is very much like a Sun dial. Facing south in the North hemisphere, you see the Sun rise in the east, slowly move clockwise across the sky; at Noon (marked with Roman numeral XII on the PRAGUE Dial) the Sun is directly overhead, where the planetary meridian your sundial’s gnomen is located on intersects a line connecting the center of Earth with the center of the Sun. After noon, the Sun continues to move clockwise across the sky and sets in the west.

On PRAGUE, the Sun also circles (in a counter clockwise direction) a ring-structure (marked with the 12 signs of the zodiac) representing the celestial sphere, indicating the location of the Sun as it slowly circles the ecliptic, passing through all 12 signs of the zodiac over the course of a seasonal year. (The 12 signs of the zodiac are really just the 12 months of a seasonal year.) The eccentric nature of this ring structure functionally represents the 23.5º tilt of the ecliptic relative to the celestial equator. The curved, radial lines marked on the background of the Dial represent the unequal hours measured by a Sun dial, which are longer in the Summer and shorter in the Winter. Draw a straight line from the center of Earth to where the Sun (in its daily orbit around the Dial) intersects the Twilight Line (separating blue from brown) and this line, extended to the outside Dial, will indicate where to place the number 24, indicating the time of Sunrise at that time of year. Those are the basic features of the Prague Calendar-Clock; state of the art and pure genius 600 years ago.

The biggest difference between MONAD and PRAGUE is that with MONAD, the Earth is spinning and makes a complete rotation every day relative to the Sun, which is fixed at noon at the top of the 24 hour dial which is located just inside the celestial ring, in the plane of the celestial equator, where clock time is measured. The ecliptic is present, tilted 23.5º relative to the celestial equator, and the Sun still travels along the ecliptic, but a celestial meridian passing through the Sun is fixed at noon at the top of the dial, making it appear that the Sun slides back and forth on this solar meridian over the course of a seasonal year.

MONAD automatically places a time zone-spanning hour hand at your location on the Earth. (Note that you are looking at the Earth from the axial perspective, which makes it easy to follow the progression of the hour hand as it rotates from one number to the next on the 24 hour Dial.) Because the hour hand is 15º wide at the base,where it emerges from the Earth globe, MONAD tells mean solar time instead of local solar time, which sun dials and the Prague Calendar-Clock tell. The User of MONAD can move the hour hand to any longitude or latitude, north or south of the equator, and tell the time at that location. PRAGUE only works for Prague, Czechoslovakia, whereas MONAD works anywhere around the globe. Plus it’s a heck of lot easier to haul around, since MONAD fits in your purse or pocket, inside your cell phone.

MONAD, like PRAGUE, has a Dial to indicate the time of Sun rise but it also shows the time of Sun set. See where it changes from black to white on the inside of the 24 hour number dial; that indicates the time of sunrise and sunset. You can adjust the latitude of the Hour Hand (use the slider marked: Lat) and see how this changes the time of sunrise and sunset, especially around the time of the solstices. Also, If you look closely, there is a little green sphere at the base of the hour hand which more precisely marks your location on the globe, and in the time zone. If this little green sphere is located at either end of the time zone (close to either edge of the hour hand), then this will impact the symmetry of sunrise and sunset displayed on the Dial because you are dealing with mean solar time instead of local solar time.

Probably the most impressive difference between PRAGUE and MONAD is that MONAD is three dimensional, featuring a three dimensional celestial ring, showing both the signs of the zodiac (on the outside of the celestial ring) and the constellations (on the inside of the celestial ring) the signs were originally named after almost 2000 years ago. Like PRAGUE, MONAD shows the location and phase of the Moon, but it also shows the location of all the other planets in the solar system. All of this astronomical activity is extremely accurately displayed, including when the planets move retrograde, all driven by the Astronomical Algorithms of Jean Meeus. Also, the constellations account for precession of the equinoxes, so the stars and planets are just where MONAD says they are, at any time and date.

Because computers can store huge amounts of information and calculate positions far faster than mechanical clocks, MONAD can rapidly shift backwards and forward in time, all while accurately representing the changing configuration of the solar system, the Sun, Moon, planets & stars. MONAD features planet Earth at the center of a time and date-telling celestial ring, but you can also observe all of this activity from the more modern, Sun-centered perspective in Helio Mode.

All 4 Modes of MONAD: Helio, Geo, Astro & Event.

Then there’s Astro Mode, which features a 2 dimensional Calendar-Clock face that allows you to set the time by dragging the Hour Hand, or set the date by dragging the calendar band or to go faster drag the zodiac band. Drag the date all the way back to your birthday and check out your birth chart. A Table at the top of the screen shows the precise location of the Sun, Moon and planets for any time and date. (Astro Mode will eventually feature an educational astronomy program and a scientific astrology program.)

MONAD also has an Event Manager (in Event Mode) which embodies the principles of chronobiology, and allows you to record personal events, including your personal biorhythms, in the context of planetary events (and planetary biorhythms) we all share. You can also record events “in the Now.” MONAD does so much more than just tell the time and date. MONAD is a worthy successor to the Prague calendar clock, appropriately sophisticated for our modern, industrial society, and also a timely reminder of our collective purpose here on this living planet: we are the gardeners and caretakers of the planetary biosphere.