We are spoilt with technology today. Thanks to Google and other digital devices, we are constantly reminded of the time. Calendars also help to remind us when equinoxes occur (equal days and nights as the sun crosses the celestial equator) or summer and winter solstices (the longest and shortest days of the year). Measuring time has always been a challenge, hence the recalculation of the leap year with the Gregorian calendar. Any year divisible by 4 is considered a leap year. The exception to this rule is if the year is also divisible by 100 – so century years skip the leap year. Further challenges arise when the century year is divisible by 400, such as the year 2000 (which was a leap year). Thanks to the Earth year being 11 minutes short of exactly 365.25 days such challenges occur, which also explains why astronomical events such as equinoxes and solstices were relevant to ancient cultures. Astronomical phenomena reliably marked seasons and were a significant part of ancient civilisation’s religious and cultural practices.
Do seasons mean as much to us today? Well it certainly did to many ancient civilisations around the world, when agricultural societies were predominant. Our ancestors left behind this evidence in various building structures. As we approached the longest day of the year in New Zealand, I’ve decided to go on a trip around the world and to revisit some of my travels to ancient sites that celebrate both astronomy and architecture.
Stonehenge is one of the world’s most famous prehistoric monuments, particularly for those wanting to celebrate equinox and solstice events. The sun alights the 26 large stones as it rises in southern England’s countryside. Such large stones were strategically placed to mark different seasons throughout the year as the Earth travels around the sun. As the sun rises, it aligns perfectly to this day with the giant heel stone, indicating the summer solstice – the longest day of the year in England.
Europe also has many splendours of combining architecture and astronomy. I didn’t have long to visit Malta, but I do recall the Mnajdra temples in Malta; three structures built over a relatively long period beginning around 3600 BC (they even predate the ancient pyramids of Egypt). It is thought the lowest temple may have been used as an astronomical site for equinoxes and solstices, although very little is known about the original design motivations. What observers can see is where light travels – the spring equinox sunrise enters the entrance to the lower temple, shining light into the passageway and onto a small shrine.
The pyramids and temples in Egypt are also a continual fascination for many. Not only did I visit Cairo and the ancient Giza pyramids but I also made time to travel to Karnak, following the Nile River south. The ancient Egyptians built Karnak Temple in Luxor around 2000 BC. It is considered one of the most sacred places in Egypt as it’s dedicated their supreme creator of the world, Amun. During the solstices, the sun’s rays light up the length of Karnak temple and into a room dedicated to Amun.
I have visited many temples throughout Asia, but I couldn’t miss the opportunity to visit Angkor Wat in Cambodia, built with a focus on astronomical events around the early 12th century (1150 AD). The Cambodians based their calendar on lunar and solar cycles. Sunrises celebrate the equinoxes as the light aligns to the central and tallest tower in Angkor Wat (standing in front of the western gate). For the Cambodians, it marked another annual journey of the sun, regardless of the exact timing of the lunar-solar New Year.
The Americas have also been a cultural wonder for their beliefs in the universe and creation of calendars. Visiting Machu Picchu in Peru was a long awaited journey – the picture postcards did not deter from the sense of awe and appreciation from seeing such an architectural wonder. Built by the Incas, their understanding of construction both below and above ground was remarkable. Perched on a hilltop, Machu Picchu has even survived earthquakes. During the equinoxes, the sun aligns with the Intihuatana Stone at midday. At this time the orb above the stone creates no shadow.
Another treat was seeing El Castillo at Chichen Itza in Mexico. It is also known as the Pyramid of Kuklukán, and was built around 1000AD in the centre of the ancient Mayan site. During the spring and autumn equinox sunsets, the light strikes an angle to create a visual illusion (shadow) of what appears to be a snake slithering down the pyramid steps to a carved head of Kuklukán. It’s debatable, but imagination can’t help but acknowledge the many sculptures, representing their snake god. Although I didn’t see such fantasies of shadowed creatures, what I did appreciate was the number of temple steps, which added up to 365 – the number of days we have in a year. Each side of the temple has 91 steps, with the 365th step positioned on top. Quite a remarkable achievement of Mayan science to create a 365-day calendar!