The ancients tried to envision the structure of the universe, but trying to understand the Universe based on the 5,000 visible stars and a few faint galaxies was impossible until telescopes revealed the structure and even the history of the universe.
The effect of telescope technology on astronomy reminds me of a detour that we took on a long mountain road during a blizzard. Without our phone map app, we would have had no way of knowing the road conditions even 100 ft ahead, but our phones enabled us to see 20 miles up the road.
Just like our phones with GPS in a blizzard, telescopes enable scientists to see galaxies and supernovae billions of light years away.
Like this image, from the Hubble Space telescope.
The telescope contributed to two major shifts in cosmology. Some of the most interesting stories in science take place when data revealed by technology such as the telescope forces a transition from traditional ways of looking at the universe to new philosophical paradigms.
The stories often begin with faint observations and creative mathematics by a lone scientist with a fertile imagination. Scientists then confirm, refute, or refine the new cosmological paradigm with improved instrumentation, mathematics, and scientific reasoning.
Oh that it was that simple! The two cosmological paradigm shifts described in this chapter involved religion, philosophy, personalities, ambition, politics, and lucky accidents. Initially, the data was not conclusive enough to prove the new hypothesis and was based on faint and uncertain observations, but the data became conclusive as scientific measurements improved.
No matter how strongly groups are entrenched against the correct interpretation of the data, they must eventually adjust their perspective because the data and the correct interpretation just keep getting clearer. The difficulty is that it sometimes takes a few decades or centuries to improve the resolution of observations or to fill in the missing parts of a theory to the point that it is certain. In the meantime, the controversies are intense. This chapter focuses on the observational, mathematical, and theoretical advances that led to the acceptance of the Big Bang Model in the 20th century.
Copernicus had proposed a new heliocentric structure of the solar system and universe in 1540 when he observed the paths of planets and developed equations that showed that the earth and planets were orbiting the sun. Copernicus’ book was initially welcomed by the Catholic Church in 1540 even though this was a radical departure from the concept that a fixed earth was the center of the universe (geocentrism); however, Copernicus’ observations were not precise and were not irrefutable proof of his new paradigm of the universe. Seventy years later, Galileo improved the design of the spyglass and developed an 8X magnification astronomical telescope by which he observed moons orbiting Jupiter and the phases of Venus as it orbited the sun. After Galileo published his discoveries in 1610 in The Starry Messenger, he became a celebrity, and everyone wanted to look through his telescope. These observations should have discredited the concept that everything in the universe revolved around a stationary earth (geocentrism) and demonstrated once and for all that the sun was the center (heliocentrism).
Although Galileo’s observations provided conclusive evidence against geocentrism, reactionary elements in the Catholic Church held on to geocentrism and put Galileo on trial in 1614 for contradicting it. The Church cleared Galileo but told him not to publish any more information on geocentrism or heliocentrism. Galileo obeyed this edict until Pope Gregory died in 1623, and Pope Urban, who was friendlier to Galileo, replaced him.
Galileo pleaded for two years with the new Pope to allow him to publish a book on heliocentrism, and the Pope eventually acquiesced but asked Galileo to also include arguments for geocentrism. Galileo published his book, Dialogue concerning two chief world systems, in 1632. He developed arguments in support of heliocentrism, but he put the arguments for geocentrism in the mouth of a foolish character named Simplicio, which meant simpleton. The book was insulting to the Pope and the Church. Galileo denied that he meant it to be demeaning, but nobody believed him, and he was placed under house arrest in 1633 for the last 10 years of his life.
There are times when sarcasm is not advisable. However, data continued to accumulate in favor of the Copernican model.
Kepler used Brahe’s maps to develop three equations that precisely described planetary orbits around the sun.
Newton (1722) then synthesized mathematics and physics in his laws of motion and gravity and thus proved that we live in a mechanistic solar system in which planetary orbits are governed by gravity.
While the heliocentric theory had been debated and accepted in schools, heliocentrism did not become official doctrine in the Catholic Church until a century and a half after Newton’s laws (1867). The Church did not endorse it because it possibly contradicted scriptures such as, “the sun moves across the sky” and seemed to contradict the senses, but the arguments (such as Herschel’s observations) became so strong that church theologians finally accepted it and concluded that the scriptures were written from the perspective of the Psalmist (poet) and did not necessarily imply geocentrism.
A similar combination of a faint observations and new equations, followed by improved observations and mathematical confirmation, shifted 20th century science from a belief in a static universe to a universe that had expanded from a small beginning; in this case, the Catholic Church led the way in acceptance of the Big Bang model, and the hostile reactions were from scientists and young earth creationists who had difficulty adjusting to the new paradigm.