What have we Discovered and Learned?
From early man until today, we have been staring at the same stars, wondering about the heavens above. The ancients studied the moon & sun to learn when to sow their crops and when to harvest. We still use this method to this day.
- c30,000BC – Bone carvings keep track of phases of Moon. Early people engraved patterns of lines on animal bones to keep track of the phases of the Moon.
- c15,000 BC – Ice Age people start to track the number of moons by scratching marks into bones.
- 1500 BC – Stonehenge was built outside of Salisbury, England. It was used to track the movement of the sun and mark the solstice. Only seven stones still stand today. This photo shows as it would have stood when it was built.
- 1200-1000 BC- Babylonians study ‘astrology’ – the belief that people’s lives were influenced by the stars. They invented the 12 signs that are still used today. Around the same time, the Greeks name most of the stars and the constellations (Hercules, Perseus, Cassiopea and Cygnus). They also name the “the wandering stars.” We now know these wandering stars as planets. The Greeks named these after their gods, Mercury, Venus, Mars & Jupiter.
- 332 BC- Alexander the Great builds a great museum-library-observatory at the mouth of the Nile in Alexandra.
- 280 BC- Aristarchus (Greek) stated that the Sun was the center of the ‘solar system’. It was almost 1800 yrs later that his theory would be widely accepted.
- 240 BC- Eratosthenes figured out the size of the Earth.
- Year O – At the time of Christ, Egyptians & Chinese were also heavily into the study of the stars.
- 120 AD- Egyptian astronomer Ptolemy (a.d. 90-168) is credited with the creation of the elaborate mechanism by which he (and later astronomers) calculated the movements of the stars and planets and the moon around the earth. Ptolemy’s most important work was completed early in his career, Almagest. Written originally in Greek, this work on astronomy was translated into Arabic in the ninth century, and in 1410 it was translated into Latin. While never completely unknown, its reappearance during the Renaissance buttressed Catholic doctrine on the centrality of human creation.
- 1054- Oriental astronomers recorded a brief flaring star, now known as a supernova.
- 1200 AD- the mariner’s compass with a magnetic needle comes into use.
- 1510 AD – Nicolaus Copernicus (1473-1543) Polish astronomer & mathemetician posumously publishs his theories that opposes common Christian beliefs of the time. The book stated that the sun was the center of our solar system. His book was banned by the Roman Catholic Church until 1835.
- 1610 AD – Galileo Galilei discovered the four largest moons of Jupiter. Io, Calista, Europa and Ganymede.
- 1618- Johannes Kepler stated that the Earth moved around the Sun in an ellipse ( a squashed circle.)
- 1905- Albert Einstein published his Theory of Relativity. This led to the famous E=MC squared (energy is equal to mass times the speed of light squared). This formula helped us understand the atom and the fact that gravity can bend light.
- 1924- Edwin Hubble (1889-1953) discovered that our Milky Way was not the center of the universe, but rather only one galaxy in among billions. He calulates the distance to the Andromeda and Triangulum ‘nebulas’. He also measures the redshift of the spectra of the galaxies and states that the universe is expanding.
- 1967- A Pulsar (a form of radiation) is discovered at Mullard Radio Astronomy Observatory at University of Cambridge.
The Mayan Stargazers:
In the Mesoamerican culture, the practice of astronomy was extremely important. To the Maya of Mesoamerica, this ancient science reflected order in the universe and the gods’ place in it. This order reflected an inherent harmony present in their general theological view of the universe. To the Mayans, capturing the essence of time was of the utmost importance. In their cosmology, space and time were inevitably intertwined, as is evidenced by their complex calendar system that combines spatial attributes of the universe, such as animals and plants, with temporal movements of astronomical objects. Although the Mayans never invented water clocks or other specific time-keeping devices, they used the sky as a method of measuring the passage of time.
The Mayans believed that celestial events were indicative of communication with the gods. Specific astronomical objects represented certain deities, whose divine lives were portrayed in the daily, monthly, and yearly changes in their appearance. The religious aspect of astronomy was also taken one step further: to astrology. The movement of constellations and other objects across the sky represented a connection between celestial events and human affairs. In other words, the practice of astronomy- in the form of astrology- was believed to have an influence on every Mayan.
Finally, probably one of the most tangible and practical benefits of astronomy was on agriculture. The appearance of certain constellations or planets in the sky heralded the planting season. The more they understood the sky, the more assurance there was that the people would not starve. It can be argued on this basis alone that astronomy was a practice which promoted the success of the Mayan civilization.
Michael Coe gives a wonderful explanation of Mayan cosmology in his article on Mesoamerican astronomy. In the center of the universe, the Earth is layer one of the upper world and the underworld. It is conceptualized as a large wheel surrounded by the teoatl, or divine water, which is an ocean that extends to the horizon. The second layer, called Ilhuicatl metzli, is where the moon and clouds reside. The fixed stars lie in the next layer, known as Citlalco, where the deity Citlallicue (“She of the Starry Skirts”) lives. The sun, also known as Ilhuicatl Tonatiuh, occupies the fourth layer, while Venus, the “Great Star,” inhabits the fifth. Layer six is called Ilhuicatl Mamalhuazocan, or “Heaven of the Fire Drill,” which represents an unidentified constellation (perhaps Orion’s Belt). This layer is also where comets (“Stars that Smoke”) come from, and where the fire serpents attend to their duty of bringing the sun from the east to the zenith. The seventh layer is the black or green heaven, fierce with winds or storms, and the eighth layer is blue heaven, which is where dust lies. The next layer, the home of thunder, is called Itztapal Nanatzcayan, or “Where Stone Slabs Crash Together.” Layers ten, eleven, and twelve represent respectively the colors white, yellow, and red. Finally, the last layer, called Omeyocan, is where the dual male-female god, who created space and time, lives.
The nine-layered underworld also played a significant part in Maya cosmology. The Milky Way was seen as a road of souls traveling to the underworld, or as the umbilical cord connecting heaven and the underworld to the Earth. As Michael Coe so eloquently states, “The Mesoamerican cosmos was one in constant flux, in which space and time were co-terminous, in which the heavenly bodies moved in fixed layers, and which was in constant peril of cataclysm”.
One of the earliest advanced civilizations, Ancient Egypt, had a rich religious tradition which permeated every aspect of society. As in most early cultures, the patterns and behaviors of the sky led to the creation of a number of myths to explain the astronomical phenomena. For the Egyptians, the practice of astronomy went beyond legend: huge temples and pyramids were built to have a certain astronomical orientation. Although many of the religious aspects of Egyptian life were known for centuries, it was not until recently that a number of archaeoastronomers attempted to find out how important astronomy really was in ancient Egypt.
Foremost of the archaeoastronomers, and one of the pioneers in the field, was Sir Norman Lockyer, a British astronomer who lived from 1836-1920 and extensively studied Egyption astronomy. In his wonderful book ‘The Dawn of Astronomy’, Lockyer breaks ancient astronomy into three distinct phases. First, a civilization goes through the worship stage, where astronomical phenomena are viewed only as the actions, moods, and warnings of the gods. Next, a civilization progresses to using astronomy for terrestrial purposes, such as for agriculture or navigation. The final step is to study astronomy solely for the sake of gaining knowledge. The Ancient Egyptians started in the worship stage and eventually began to see how astronomy could help them in their everyday lives.
The Egyptian gods and goddesses were numerous and are pictured in many paintings and murals. Certain gods were seen in the constellations, and others were represented by actual astronomical bodies. The constellation Orion, for instance, represented Osiris, who was the god of death, rebirth, and the afterlife. The Milky Way represented the sky goddess Nut giving birth to the sun god Ra. In the picture below, Nut is shown bending over the Egyptians. The stars in Egyptian mythology were represented by the goddess of writing, Seshat, while the Moon was either Thoth, the god of wisdom and writing, or Khons, a child moon god.
The horizon was extremely important to the Egyptians, since it was here that the Sun appeared and disappeared daily. A hymn to the Sun god Ra shows this reverance: ‘O Ra! In thine egg, radiant in thy disk, shining forth from the horizon, swimming over the steel firmament.’ The Sun itself was represented by several gods, depending on its position. A rising morning Sun was Horus, the divine child of Osiris and Isis. The noon Sun was Ra because of its incredible strength. The evening Sun became Atum, the creator god who lifted pharoahs from their tombs to the stars. The red color of the Sun at sunset was considered to be the blood from the Sun god as he died. After the Sun had set, it became Osiris, god of death and rebirth. In this way, night was associated with death and day with life or rebirth. This reflects the typical Egyptian idea of immortality.
- Saturn would float if it was put on water.
- If you would place a pinhead sized piece of the Sun on the Earth you would die from standing within 145 km (90 miles) from it.
- Space is not a complete vacuum, there are about 3 atoms per cubic meter of space.
- Only 5% of the universe is made up of normal matter, 25% is dark matter and 70% is dark energy.
- Neutron stars are so dense that a teaspoon of them would be equal to the weight of the entire Earth’s population.
- The Sun is 400 times larger than the Moon but is 400 times further away from Earth making them appear the same size.
- The star Lucy in the constellation Centaurus is a huge cosmic diamond of 10 billion trillion trillion carats.
- Seasons last 21 years on Uranus while each pole has 42 years of sunlight followed by 42 years of darkness.
- Venus,on the other hand, does not have any seasons at all.
- 1 year on Mercury consists of less than 2 days on Mercury.