Writing by Ray Honeysett. Illustration by Ray Honeysett.
Newton and Galileo are household names. Even those who aren’t familiar with their full works on gravitation will know their names from the story about the falling apple, or from a verse of Bohemian Rhapsody. Lesser known, at least in the UK, are the names of Brahmagupta, Abul Abbas and Aryabhata, and yet their contributions to astronomy have been vast. Each of the continents have their own stories and scientific contributions, many of which have been ignored too long. Africa is home to the oldest surviving observatory in the world, for example. The Nabta Playa stone circle lies in the Egyptian section of the Nubian Desert, on the Sudanese border. At over 7000 years old, this stone circle predates Stonehenge by millennia. The gates of the circle align with the placement of the rising sun at equinox and solstice. This innovation was very important to the civilisation around it; if they could tell what time of year it was, they could predict their rainfall season, and know when to plant their crops so that they would be most likely to thrive.
Many other civilisations, to this day, use the stars to plan their agriculture. In Australia, the most famous constellation, the Great Celestial Emu, or Gugurmin in the Wiradjuri language, is used to tell the nesting times of emus. The constellation is unusual in that rather than being made up of stars, it’s composed of the dark shadows in the Milky Way. When Gugurmin makes its way overhead during sunset, this means that it is the right time of year to scavenge for Emu eggs. The Dogon people of Mali have a designated astronomer in each of their communities, who is responsible for keeping track of the right times of year to build, plant, travel and harvest. This tradition of astronomy in Mali comes from a rich history of astronomical research; 15th century Timbuktu was a haven for scholars, with extensive teaching in astronomy, optics and maths. The university there was home to many of the greatest astronomers. One such person was Abul Abbas. As a devout Muslim, Abbas studied the stars and realised that astronomy could be used to determine the direction of Mecca from Mali, so that mosques could be built in the right direction for prayer. Another use of astronomy that Abbas saw was time keeping - knowing what the seasons were and what time of year it was. Abbas created an algorithm to figure out when leap years in the Islamic calendar should occur; in 2008, scientists made his algorithm into a computer program, and showed that Abbas was correct.
Abbas is not the only historical astronomer of note; thousands of miles away, and centuries before, the eminent Indian astronomers Aryabhata and Brahmagupta were making strides in science. As early as the 5th AD, Aryabhata had discovered that the solar system was heliocentric, with the Earth orbiting the Sun. This discovery was made a millennium before Galileo made this common knowledge in Europe. The fact that this was discovered so much earlier in India than Europe points to a lesson in why diverse perspectives are important in science. In Europe, where Christianity dominated, it was considered heresy to suggest that the Earth was not the centre of everything. Aryabhata provided a Hindu perspective on the cosmos, open to the idea of humanity just being a part of a bigger picture.
Following on from Aryabhata’s work, Brahmagupta, an Indian mathematician and astronomer in the 6th century, made a whole host of important discoveries himself. Best known for ‘inventing zero,’ Brahmagupta was perhaps the first person to discover gravity. He saw that the force responsible for things falling to the Earth must be due to its bulk, and that this same force must be what caused the Earth to rotate around the Sun.
The value of scientific perspectives from around the world can also be seen in the creation stories from New Zealand. Dr Pauline Harris, chair of the Society of Māori Astronomy Research and Traditions (SMART), makes a compelling case that the Big Bang could have been discovered much sooner if Māori scientists had been allowed to thrive. An important creation story in Māori culture is that the universe began when the sky and the Earth were pressed together, and then they expanded apart, creating the space we have today. This bears a striking resemblance to the Big Bang theory.
Even in Western countries, the contributions of those who are not old white men have often been ignored or suppressed. Ireland boasts a line of pioneering female astronomers, from Agnes Mary Clerke, who studied star life-cycles, to the University of Edinburgh’s own Mary Brück, to Jocelyn Bell, who discovered pulsars. Across the Atlantic, similar patterns of suppression hold true. Henrietta Leavitt was an American astronomer who has had a vast impact on the landscape of astrophysics. She discovered a link between the brightness and variation of a type of star called Cepheids. From studying how regularly these stars twinkle, the distance to their galaxies can be found. This relationship has since been used to discover that the universe is expanding, and to calculate the age of the universe. Despite her enormous contributions to astronomy, Leavitt received no recognition in her time. She was underpaid and unappreciated, working as a ‘computer’ for Harvard, who hired her because they were not legally required to pay her.
Native American knowledge has also been suppressed and ignored. Many Native tribes have historically had accurate knowledge of the placement of the stars at different times of year, especially the native Hawaiian people, who used celestial navigation to travel the Pacific. In recent years, astronomy has been more of a threat than a benefit to native Hawaiians; Western scientists have been building telescopes on the sacred Mauna Kea since 1964.
Not all recent astronomy is Western-focused, thankfully. The Square Kilometre Array (SKA), which will be the world’s largest radio telescope, is being built half in South Africa and half in Australia. It will be used to investigate many sources of radio-waves across the universe. One of the SKA research goals is to find the spread of hydrogen atoms and use this to map the universe’s expansion, in order to find out more about dark energy. Construction of SKA in Australia is on indigenous-owned land and has been done in partnership with the Wajarri Yamatji. To celebrate the international collaboration, indigenous Australian and South African artists worked together to make an art exhibition sharing their mutual love of astronomy (which you can find here! https://www.skatelescope.org/shared-sky/virtual-gallery/).
Taking a whole worldview of astrophysics does not just make the world fairer; it also means that we are more likely to make breakthroughs. If the Māori view of creation hadn’t been suppressed, we might have discovered the Big Bang theory sooner. If the insights of Brahmagupta and Aryabhata had travelled sooner, our understanding of gravity would have been advanced by hundreds of years. By making sure that the whole world has a place in the scientific community, we get a step closer to increasing our knowledge of the universe.