Giordano Bruno (1548-1600) was an Italian philosopher who lived in the wrong time period, as the people of his day were still repeatedly attempting to establish a connection between spiritually-based knowledge and modern scientifically-based astronomy. Planetary spirits like angels and archangels and angel’s wings were used to explain the movements of the cosmos. Ancient man thought the stars were pinpoints of light that rotated slowly around the Earth. Copernicus placed the Sun in the center of the universe instead of the Earth, but he retained an outer sphere of fixed stars at the edge of our solar system, just like the Ptolemaic universe. Bruno conceived a bold concept of a universe extending outward infinitely, containing suns without end, with each perhaps racing through space with its own family of planets.
The first person known to suggest that the Sun is a star (or, conversely, that stars are Suns) was Anaxagoras, around 450 BC. Around 220 BC, this was suggested again by Aristarchus of Samos, but this idea did not catch on. Titus Lucretius Carus a Roman poet and philosopher in the first century BC suggested the concept of an infinite universe, but he had no notion that the stars were suns. Lucretius argued that the universe is infinite consisting of infinitely extended space and an infinite number of atoms. He said that our world was not formed around a spherical earth, itself located at the universe’s centre. Parallax is the apparent change in position of objects due to a change in observation location. The ancient Greeks claimed that if the Earth is moving around the Sun then the stars should shift their positions due to this orbital motion (called stellar parallax), but the stars didn’t shift, or the shift was not noticeable because these stars were much further away than anyone realized.
In 1584, Giordano Bruno used his daring and perceptive insights into reality when he asserted that the stars were just like our Sun, but they were so far away that their apparent displacement due to the Earth’s revolution about the Sun could not be detected. Giordano Bruno decided that if the Earth is a planet just like many others, and that it does not make sense to divide the Universe into a sphere of fixed stars and a solar system. He said that the Sun is a star, that the Universe is infinitely large, and that it contains many worlds. He was condemned by both the Roman Catholic and Reformed Churches for his rebel views. In 1600, Giordano Bruno was declared to be a heretic and he was burnt at the stake, for asserting that the Sun is a star, among other things. Bruno should be honored for introducing the immense universe to the world which he did before the telescope entered into modern astronomy. Bruno gave us countless billions of suns shining across space from incredible distances, a universe in which both Earth and Sun shrink to insignificant size and importance.