A Meditation on Science: Bed-time Story Astronomy, part I
Bed-time Story Astronomy, part I
[Image: Mars does a “loop da loop” as the wanders do. Image published by NASA.]
Published: 2022-11-23
The meditation continues in Part II.
Introduction
I have developed a series of "stories" which I tell myself, meditations, to calm my mind to sleep. They concern science or its history. This series, A Meditation on Science, will recount some of these stories.
The stories are dominated by science developed in Europe and North America. There are other great stories of science and engineering from other cultures. Science would never have "worked" without the printing press and the printing press would not really have been useful without paper. Paper was developed in China.
Astronomy can loosely be traced to the development of an accurate calendar. Independently of Europe, central American cultures developed calendars more accurate than those of the same in Europe. The wealth which was able to be invested in European science was derived from the exploitation of other cultures during the periods of colonization.
With these caveats out of the way, here is the Astronomy meditation.
Calendars
Calendars are potentially useful for improving agriculture. However, just as one does not need a meteorologist to tell you what the weather is, just go outside, one does not need an astronomer to tell you when to plant your crops, just ask a farmer. Calendars are more useful for the scheduling of cultural or religious events. They are useful for the coarse measurement of time, and were certainly valuable for planning long voyages over sea or land, whether one is holding a Crusade to the holy land or attempting a trading mission to the spice islands of Indonesia.
Stars and Planets
Every human society has been fascinated with the stars of the night sky. Most societies have drawn mental pictures upon them, from which Europe gets its constellations and the star signs of Astrology. A backdrop of stars which hold position with respect to those around them rotates across the sky each night. Interestingly, some constellations can only be seen from northern or southern latitudes.
There is no "pole star" in the southern hemisphere. The replacement mechanism involves that which sounds complex but is very simple. You take the long axis of the southern cross and draw a line through it. There are two bright stars close together called "the pointers". You draw a line which passes between them (the perpendicular bisector). Where these lines cross is the southern celestial pole. Leaving this factum aside, we return to the meditation.
There are lights in the sky which do move with respect to those that stay fixed relative to those around them as the night sky "rotates". These errant "stars" were labeled by the Greeks as planets, which means "wanderers". Wander they do. Most quizzical is the path they take across the "fixed background". While the background rotates across the sky, the wanders move among them. It is the path which causes puzzlement.
Our star, the sun, or sol, moves smoothly across the sky and blinds us to all else when it shines upon us. Our moon, with regularity, moves around us and shows its phases predictably. The background night sky rotates smoothly across the heavens. But, the planets take strange detours. They move across and then up or down and then begin to head in the reverse direction before returning to their standard path. There are no other "lights in the sky" which do this. They are asking us; why?
Back in the 16th century at the beginning of the Renaissance, Europe was rediscovering the legacy of ancient Greece in art and their literature and philosophy. A Caliph of Baghdad had funded the "translation project" to translate all interesting written works from whichever language into Arabic some half a millennia earlier. This Muslim funded investment into capturing and preserving knowledge proved a boon to Europe as it re-explored a faded empire. Byzantium, and thus the Eastern Roman Empire, had only recently fallen to the Turks in 1453.
At this time of the Renaissance beginning, the son of a Danish nobleman by the name of Tycho Brahe established an observatory on the small and beautiful island of Ven between current Sweden and Denmark. There, equipped with a compass, a carefully measured arc of elevation and the best clock available he took measurements of the night stars for years. This data, or the triplicate of angle of compass, elevation and time at one location was a compendium of records of the night sky.
Europe was still in the thrall of understanding administered by the (Western) Roman Catholic Church. The church agreed with the obvious assessment that the heavens, and thus what we now call the cosmos, was rotating around Earth. This is known as the "geocentric" model. Those planets' motion, as carefully recorded by Brahe, made their way to the court in Vienna. There, scholars had conceived as had the Greek Aristarchus two millennia earlier that there was another model. It was not the Earth which was the center of the heavens, but the Sun. This heretical idea is the "heliocentric" model, named from the Greek "Helios" for sun.
Using the Dane's data and considering the problem of the irregular "orbits" of the planets, Nicolaus Copernicus and Johannes Kepler had reasoned new proposals to further our understanding of celestial mechanics which lead towards the heliocentric model.
The Telescope
The existence of and ability to create glass has been known world wide beyond antiquity. The Romans’ developed an ability to forge or craft glass, known as glass blowing. So special was this skill that an island off the near coast of Venice was assigned to house those who learned and preserved the skill. A person of capability was given a choice. You may be trained in the art and craft of glass blowing. However, this requires that you move to this island with your family and you may never leave this island. You will be well cared for, and as a trade for your imprisonment on this island, your children may marry into noble families. This was essentially a prototype patent system to contain and retain craft skills.
During the later period of the Roman empire "wine connoisseurs" emerged. They wished to not only woo their guests with the aroma and flavours of their wine, but also display its colour. For this clear glass drinking vessels were required, which the Venetian glass blowers could produce. In the end, clear glass resurfaces in the production of eye glasses. These could prolong the careers of skilled persons in areas of law, accounting or engineering, or really any upper class profession by years, as their eyesight degraded with age. The practice at the time was that glass polishers would produce a collection of lenses and trial and error would largely be applied to identify which lens or lenses may assist an individual.
In 1607 a registration is made at the Dutch Patent Office for a telescope.
Galileo di Vincenzo Bonaiuti de' Galilei (GG)
Galileo was born into a moment of transition. The Italian city states were prospering due to various advantages which they had created. The "credit notes" of our modern banking were developed. They understood how to fix dyes using Alum. Their ship building was second to none. They dominated shipping trade in the Mediterranean.
That which Galileo observed is reasonably well known. The process which he used is far less well known. Sub-atomic physicist and science publicist Professor Jim Al-Khalili and I agree on many matters. One stands out. It is the methodology which Galileo used after constructing a telescope which is one of, if not the most, important in the development of European science.
With his telescope, GG observed the night sky. Quite unsurprisingly he chose the planets as some of his observations. One planet, Jupiter, caught his attention. He saw small unknown "lights" about it. There was no photography. He, like any trained "scientist" in his age had learned draftsmanship or 'technical drawing' as we now call it. Seeing these unknown "lights" around Jupiter he recorded the images by drawing. Over weeks of observation using this new tool, the telescope, he had recorded the movements of these "lights" close to Jupiter. They moved from one side, then disappeared, and re-emerged on the other side of Jupiter to repeat the process transitioning again to the other side.
There was only one logical explanation for this. These are not stars. They are moons, and they are orbiting Jupiter. This conclusion comes from using a new instrument, repeated observation, the recording of these observations, and then considering their meaning. Convinced of his understanding, he authored a small book and had it printed, declaring his methodology, observations and conclusions.
This, in 1610, had every element of modern science, except peer review. This publication is the defining moment of the transition from Alchemy (researching and not telling anyone about it) to Science (researching and publishing your findings).
The four moons he identified, Io, Europa, Callisto and Ganymede are known to this day as the "Galilean Moons" of Jupiter.
Consequences
Obviously, the Roman Catholic Church was mightily pissed off about this upstart contravening their dogma. GG was excommunicated from the Church, which was a potential death sentence at the time. But, GG was a clever man and the Patriarchs (we now call them oligarchs) of a city state or two were wooed by his offer of useful technology. A telescope is tuned to look for the stars, but a smaller flexible version can provide long distance terrestrial vision.
In "pirate" films one will see people using a brass tube to see into the distance on the water. GG developed these and sold them to maritime Italian city states to secure his well being. The benefit to the city state Patriarchs was that their security services would see potentially threatening approaching vessels sooner. This added time to prepare defenses.
The major intellectual consequence was that published evidence, which anyone who had a telescope could verify, had been issued. A collection of moons orbited Jupiter, not Earth. This was the death knell for the "geocentric" model and birthed a new understanding of our place in the "heavens" or "cosmos".
The sun was center. There are more subtle re-understandings too. Our moon obits us. Jupiter's moons obit Jupiter. Thus, moons are a "local thing". GG's work is a worthy predecessor of Sir Isaac Newton's "Principia" and the beginnings of a study of "gravity".
The lasting consequence is that this intelligent, Italian man laid the foundation for European science to come: to research, analyze, consider and publish.
Astronomy and "western science" were born.
Sources
Probably.
Culture
Science is a part of culture. Sleep is just required.
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