Tuesday, February 28, 2023

Thought Experiments & Imagination

Thought Experiments 

How To Use Your Imagination 
to Understand the Ancient Past

Einstein and a light beam.
Around the age of 16, Einstein began to imagine what he would see if he were riding a beam of light. Ten years later, due to his thought experiment, he made a breakthrough in his understanding which led to his Theory of Special Relativity. 
Your cell phone and many other things could not operate without his discovery.
This article is for people who are studying prehistory. But it also applies to anyone who is working with a problem in science and wants to experiment with a new approach.
To investigate the past, we must rid ourselves of our modern point of view and try to look at the past from its own point of view. Unless we can do this we will not be able to grasp how the past transpired and also how it connects to the modern day. 

One way to free ourselves
is to use our imaginations. 

However, your imagination is only one of many tools in your toolbox. Logic is another tool, as is finding direct and indirect evidence, following hunches and intuitions, and locating opinions from respected authorities. In an effort to prove something, you will probably use a combination of tools.

In this article, I will start with examples of important "thought experiments," experiments by Galileo and Einstein, in which they imagined a set of circumstances. What they revealed and discovered via their imaginings changed science and our modern world. 

I believe that people who investigate prehistory can also benefit from this approach. They can use their imagination to go back in time and then place themselves in that time period. If you suddenly time-traveled to a Mesopotamian city 5000 years ago standing on a street corner, what would you see, what would you hear, what would you smell, what would you touch?
(Be sure to read the next blog which will be a detailed fictional time-travel journey to Mesopotamia.)


ABOUT THOUGHT EXPERIMENTS

Thought experiments, as they are called, have a surprisingly long recorded history. To prove a point or to work out a problem, the experimenter imagines a situation that reveals information. One of the first recorded such experiments came from Galileo and it was very important.


GALILEO'S SHIP

Galileo's 1632 book, Dialogue Concerning The Two Chief World Systems, considered all the common arguments against the new idea that the Earth rotates at a rapid speed around its axis and also orbits the Sun. This was the book that got him into trouble with the church.

"One of the contrary arguments was that if the Earth were spinning on its axis, then we would all be moving to the East at thousands of kilometers per hour so a ball dropped straight down from a tower would land West of the tower which would have moved some distance East in the interim."

For Galileo's thought experiment to work, he had to find a vehicle that moved smoothly without bumps or jerking. It had to be a motion that would not be felt. In the modern world, we are used to this such as riding in cars or trains or planes. But in Galileo's time, boats were the best vehicles for illustrating his ideas. 
https://commons.wikimedia.org/wiki/File:Lybska_Svan.jpeg

Galileo created a character in his book, whom he named Salviati, to make his argument. He explained why we do not feel this motion, using a thought experiment. Salviati says:
Shut yourself up with some friend in the main cabin below decks on some large ship, and have with you there some flies, butterflies, and other small flying animals. Have a large bowl of water with some fish in it; hang up a bottle that empties drop by drop into a wide vessel beneath it. With the ship standing still, observe carefully how the little animals fly with equal speed to all sides of the cabin. The fish swim indifferently in all directions; the drops fall into the vessel beneath; and, in throwing something to your friend, you need to throw it no more strongly in one direction than another, the distances being equal; jumping with your feet together, you pass equal spaces in every direction. When you have observed all these things carefully (though doubtless when the ship is standing still everything must happen in this way), have the ship proceed with any speed you like, so long as the motion is uniform and not fluctuating this way and that. You will discover not the least change in all the effects named, nor could you tell from any of them whether the ship was moving or standing still. In jumping, you will pass on the floor the same spaces as before, nor will you make larger jumps toward the stern than toward the prow even though the ship is moving quite rapidly, despite the fact that during the time that you are in the air the floor under you will be going in a direction opposite to your jump.

Galileo Galilei, Dialogue Concerning the Two Chief World Systems (1632), translated by Stillman Drake, University of California Press, 1953, pp. 186 - 187 (Second Day).

With this experiment, he showed how the Earth could constantly rotate 1,000 miles an hour and also move over 60,000 miles an hour in its orbit around the sun. But we on Earth would not feel it.

"What did Galileo's thought experiment prove?
"Galileo concluded that all objects on Earth and within its atmosphere share in its motion. As a result, they are unaffected by its motion, just as if they were stationary."
Galileo's Thought Experiment


EINSTEIN'S THOUGHT EXPERIMENTS

Einstein's thought experiment (next) was equally important and was, in many ways, similar to what Galileo had imagined. In both cases, the experimenter is inside a moving vehicle but the environment inside that vehicle is normal and the same as if the vehicle were still. So the environment of the interior is not influenced by the motion of the vehicle.

However, there was a significant difference between them. In Galileo's case, he was explaining something he had already decided. He believed the Earth went around the Sun and was looking for a clear way to explain it. In Einstein's case, he had made a discovery, because his thought experiment led directly to new ideas in the Theory of Special  Relativity. 

In this theory, Einstein proved that time was relative. But even though he had this revelation, he still had to do the hard work of figuring out the math, which he did immediately after this event.

The street car in Bern Switzerland
and the Zytglogge (bell ringing) clock above it.
The clock was made around 1400 CE.

“[Einstein's] first thought experiment has to do with time and stems from a thought Einstein had while riding home in a streetcar in Bern. He saw the clock tower passing behind him and wondered how the clock would appear as the streetcar moved faster and faster,” writes Chris Impey of Teach Astronomy.

"Einstein heard the toll one evening in May 1905. He had been confounded by a scientific paradox for a decade, and when he gazed up at the tower he suddenly imagined an unimaginable scene. What, he wondered, would happen if a streetcar raced away from the tower at the speed of light?
"If he was sitting in the streetcar, he realized, his watch would still be ticking. But looking back at the tower, the clock – and time – would seem to have stopped. It was a breakthrough moment."

Einstein's discovery was, in some ways, a combination of a thought experiment and idea-incubation. Idea-incubation means that you have been working on an idea, give up, and then suddenly the answer comes to you. Einstein had been thinking about light from the age of 16. He had wondered then what it would be like to ride a beam of light. So this idea had been rolling around in his head for some time. And on that fateful night, it came together.

I also find it fascinating that Einstein's imagination was kicked into high gear because of the sound of the clock's bell. It was a medieval clock in Bern Switzerland called Zytglogge and it had an ancient connection that reached back to the beginning of timekeeping and time itself. 

At the top of the clock tower in Bern, the Greek god of time, Chronos,
rings the specially made bell (installed in 1405) each hour.
He is a primeval god who created time itself.

The clock was built with Ptolemy's approx. 2000-year-old ancient geocentric system. The clock's gearing was based on Ptolemy's Earth-centered astronomical geometry. But just as important, the bell that rang was rung by a mechanical model of the ancient Greek god of time, Chronos (where we get the word chronology). And Chronos was not just any old Greek god. He was a primeval god who, at the very beginning of creation, brought the world into being, and then time itself. [1]

While Einstein was well aware of Greek philosophy and drama, he may not have had a detailed knowledge of Greek mythology. This mythology contained many tellings of the same story which often conflicted, and it would have taken a good deal of research to understand the powers and importance of each god. It is my belief that imagination, intuition, and things like thought experiments can often connect to unconscious ideas and long-forgotten cultural narratives. In this case, Einstein's new ideas about time were connected with the Western history of time concepts back to the very beginning, the birth of time. 


HOW DOES THIS RELATE TO THE STUDY OF PREHISTORY?

On the subject of studying prehistory author, Chris Gordon, had this to say.

"This is where the study of prehistory comes in — a method of UNLEARNING THE PRESENT [my emphasis] and developing an understanding of the past."
Gosden, Chris, 'The problems of prehistory', Prehistory: A Very Short Introduction, 1st edn, Very Short Introductions (Oxford, 2003; online edn, Oxford Academic, 24 Sept. 2013), https://doi.org/10.1093/actrade/9780192803436.003.0002, accessed 29 Jan. 2023.

Part of the problem is that we are modern people and it is almost impossible to rid ourselves of our modern attitudes. 

To paraphrase what my friend Barbara Blake, a Ph.D., in Anthropology, said to me: our culture is so much a part of each of us that it is virtually impossible to rid ourselves of its influence. And many of our biases are so built-in, we may not be aware of them.

So with our imagination, we need to do two things. The first is to "unlearn the present" by mentally undressing and shedding our modern point of view.

Then next, with our imagination, try to go back into the ancient past and see it more clearly from the perspective of each time period and each culture. 

But to do this we need some ground rules.

The first task is to rid ourselves of outdated ideas about 'stone age', 'primitive', 'savage', and 'uncivilized' people. This needs to be done first before we can tackle more specific biases such as assumptions about various technologies, for example. 

But old ideas and attitudes are hard to shed.  Lewis H. Morgan wrote, more than a hundred years ago, that the evolution of humanity went from savagery to barbarism to civilization, meaning that the Neolithic cultures were barbaric and Paleolithic people were savages. And for many people, this attitude has remained. 

The second task is to forget air conditioning and refrigerators and cars and highways and soft mattresses and cell phones. When considering prehistory in particular, you will have to forgo most modern comforts. So you will need to forget even basic things such as running water and toilets. And you may need to keep a fire going constantly along with finding and storing wood. Also, imagine that instead of going to a store you have to make every tool and container you use. You will probably need to know how to make a variety of baskets. You grow all the food you eat and you make all your clothes. Every day you spend hours getting water and grinding grain and making bread.

The third task is to be open to the unexpected, to consider that in these harsh environments, ancient people might have created remarkable things or very different things that we would not expect. 

But the problem with understanding prehistory only gets worse and more difficult as you go back in time, into the Paleolithic, for example. Finding evidence and dating it is hard for the Upper Paleolithic, very hard for the Middle Paleolithic, and almost impossible for the Lower Paleolithic. Not only does evidence decay or is degraded or buried but the hominins involved are increasingly different.

So the study of prehistory might make use of imaginative tools because so much is hidden from us. By rethinking or reimagining the past, it is possible that we could see things that have been overlooked or connections that have not been made.
See an example of imaginative rethinking later in this article. This example describes a new insight into how the famous Australopithecus, Lucy, died.

A REAL-WORLD EXAMPLE OF USING YOUR IMAGINATION

How I Developed The Idea
That A Neolithic Culture Could Be More Advanced
Than The Romans 3000 Years Later 

The winter solstice is not just a day on the calendar. Our local and much-loved weatherman, Skip Waters, made the point that the time period of the winter solstice occurs for about a week, not just a day. And that it was virtually impossible to know the specific day of the solstice through direct observation as there was only a few seconds' difference in the length of the day and a tiny degree difference in the position of the sun during that week. Measuring the sun's position was further complicated by atmospheric refraction. It was not until the 18th Century that the winter solstice could be determined optically by direct observation.

However, to everyone's surprise, archaeologists discovered that the Neolithic culture at Newgrange Ireland had somehow overcome these difficulties by building a huge passageway with a special roof-box that was aligned with the solstice sun. And this got me wondering if other cultures, even 3000 years later such as Rome, could do this.

Outside (top) and overview (bottom) of the passage tomb at Newgrange from 1897. It took another 70 years before Newgrange was fully understood, partly due to modern misconceptions about the capabilities of prehistoric people.
Coffey, George. Drawings of Newgrange from the late 1800s. Published in: The Dolmens of Ireland,, by William Copeland Borlase. Published by the University of Michigan Library (January 1, 1897).
NOTE: I have used Newgrange as an example many times in these articles because it illustrates so many things when dealing with prehistory: a Neolithic structure that was misunderstood for hundreds of years and then positive proof that it was a well-made and accurate device. 
To begin I read translations of Roman accounts about the week-long Saturnalia festival. The name comes from the Roman god Saturn. a god who was Roman and not an adoption of a Greek god. He was associated with time, the harvest, periodic renewal, and liberation. His festival comes at the end of the year and is a time for wild celebration. Today, the weekday, Saturday, is named for him because it is a time when we can relax, kick back and enjoy that the week has come to an end. 

Roman depictions of the god Saturn, an old man with a full beard, who was, among other things, the god of time. He held a sickle which was a symbol of harvest and bounty and also death and destruction. Bas-relief, 2nd century CE.
https://commons.wikimedia.org/wiki/File:0_Autel_d%C3%A9di%C3%A9_au_dieu_Malakb%C3%AAl_et_aux_dieux_de_Palmyra_-_Musei_Capitolini_%281b%29.JPG

The Saturnalia festival was a time when the darkness was celebrated as a joyous time. So, using my imagination, I put myself back into that time. What I saw as I walked through Rome was continuing darkness with no real change for about a week. It was the week that was celebrated and not the day. There were parties when special lamps were lit to light the darkness. Special foods were made, special songs were sung, and presents were exchanged. Then on December 25, when it was clear that the sun had stopped its winter decline and was now returning and getting brighter, that this later day was celebrated as the day of the sun's return.

But it seemed to me that the actual day of the solstice was not something that was determined nor was it that important to the Romans. What was important was the week-long festival, a time period of "solar standstill" (the Latin meaning of the word solstice).

But this relationship to the solstice was quite different in Ireland where the day was an hour and a half shorter than the solstice day in Rome. I did not have written accounts but I did have the carefully made building at Newgrange, which in a sense, could talk to me.

I imagined the cold climate of Northern Ireland and an agricultural way of life. How would you feel as the sun sank lower and it got dark earlier each day, when the plants had stopped growing and lost their leaves, and they appeared to be dead? Imagine what it would have felt like as the days got shorter and the temperature colder and colder. So when I imagined myself in Ireland during the time of the solstice, I felt fear and dread. What I needed was a way to be reassured that the Sun would return and crops would grow again.

So, I believe, the Irish built a huge, sophisticated, complex monument to determine the exact time of the solstice. 

The passageway at the Newgrange passage tomb in Ireland.
While this looks crude to our modern eyes, the alignment and placement of the stones were exact and by magnifying the sun's angle and movement could determine the day of the solstice in real-time.
LEFT: "A section of the passage leading towards the chamber of the Newgrange passage tomb in Ireland."
RIGHT: The light of the solstice in the passageway in 2013.

After reading a description by the archaeologist Michael J. O'Kelly who discovered the solstice alignment of the Newgrange monument, I again put myself back in time. I stood in the Newgrange passageway, at the far end, as sunlight entered on the day of the winter solstice. I watched the sunlight quickly move toward me for about eight minutes until I was bathed in its light at the furthest reach of the hallway. And then I watched it retreat. This annual event would have been reassuring to these Neolithic people and it also signaled a profound bond between the Sun and the Earth. Clearly, this was a very different relationship than that of the Romans.

This led me to wonder if the Newgrange "instrument" as I have called it because it was like a scientific instrument, was more precise than what the Romans had. And my research seemed to bear this out. But if that were true, it completely changes the generally accepted timeline of Classical cultures vs. Neolithic cultures. It was always assumed that the Romans were far superior and more advanced in every way than the primitive, barbarian Neolithic people. And in many cases, the Romans were superior but perhaps not in this case. 

To put it simply, the Neolithic people felt a compelling need to create a precise accurate device that could indicate the exact day of the winter solstice. So they made such a device. The Romans did not feel such a need.

So my "imagination experiment" led me to research how the Romans did determine the day of the solstice. An expert on Roman astronomy said they could calculate the day of the solstice after the fact by interpolating measurements made before and after the solstice, but not in real-time as the people at Newgrange could. So if true, the Newgrange technology was superior 3000 years before the Romans.
Dr. Dennis Duke, "Four Lost Episodes in Ancient Solar Theory, Journal for the History of Astronomy," (2008)


A CONTEMPORARY EXAMPLE 

When I was writing this article, I wondered if there were any recent examples I could point to. So I thought about various scientific articles I had read. One study seemed like a good candidate. When I read it in depth I found that a key part of the study came about due to a man's imagination. A professor who had been working with the bones of the famous Australopithecus, Lucy, suddenly could see how she died, and knowing that also told him a lot about the way she and her people lived.

This is a perfect example of how to rethink a time period. Lucy, he decided, died because she fell from a high point in a tree. Nine orthopedic surgeons also looked at the bones and agreed that her fractures would have occurred due to a fall. So if what Dr. Kappelman says is true, and not all authorities agree, it changes many commonly held ideas about whether early hominins lived and slept in trees.

“I have taught this fossil since I was a grad student in the 1980s,” says John Kappelman, a professor of anthropology at the University of Texas at Austin and lead author of the study, which was published in the journal, Nature. “I knew these fractures were there, I just never thought to ask what had caused them. No one, as far as I know, has ever put out a theory of how she died.”

Lucy's bones, one of the most complete skeletons of early hominins.

“At one point, I had all these bones out and this idea just finally crystalized—I could see the fall, the position of her body when she hit, the impact,” says Kappelman. “For the very first time, I saw her as an individual and this wave of empathy hit me. For the first time, she was not just an isolated box of broken bones. I could actually picture how she died.”


PUTTING YOUR IMAGINATION TO USE

As I have suggested, the best way to free yourself from a modern bias might be to use your imagination. I suggest, for example, that you go back in time to a prehistoric place and take off all your clothes. Then put on clothes that were probably common then. Do some research to find out what kind of clothes they wore. 

How does it feel to move and sit and work in those clothes, for example? How does the fabric or animal skin feel? Do you have shoes or a hat? What about a belt or pockets? What are they made of? How are they all put together?

HERE ARE SOME OTHER TIMES TO IMAGINE
-- Imagine a city in the world's first civilization, Mesopotamia
Next month read my next blog-article about time-traveling to Mesopotamia and walking around a city.
-- Imagine the Neolithic
Imagine you land in a small Neolithic village about 10,000 years ago.
-- Imagine the Mesolithic
Imagine you are part of a tribe of people who are hunter-gatherers for part of the year and settled in huts for other parts of the year.
-- Imagine the Upper Paleolithic
Imagine belonging to a tribe that lives in caves some of the time but is nomadic all year long.
-- Imagine the Lower Paleolithic
Imagine you are with hominins who are nomadic hunter-gatherers and often camp near or in Baobab trees on the African plains.

Time-travel to a time 5000 years ago in Mesopotamia
-- next article, next month.
This picture is a bird's eye view of a Mesopotamian city.
My next blog-article will be an imaginative walkthrough
 in such a city to see what we can see. :) [2]


[1] CHRONOS (also KHRONOS) was the primordial god of time. In the Orphic cosmogony, he emerged self-formed at the dawn of creation.
He and his consort, the serpentine goddess Ananke (Inevitability), enveloped the primordial world-egg in their coils and split it apart to form the ordered universe of earth, sea, and sky. After this act of creation, the couple circled the cosmos driving the rotation of heaven and the eternal passage of time. 
[2] brown_u_landscape.pdf


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