Comprehending the Incomprehensible

The most incomprehensible thing about the universe is that it is comprehensible. A. Einstein

                                                           

Last month, I made a vain attempt to define energy; as an adjunct to that article I felt it worthwhile exploring human scientific thought and development generally. The human pursuit of understanding the natural world and all that surrounds us culminates with the ultimate answers to the ultimate questions: ‘Where did it all come from’?  And - ‘what the heck is it all about’?

During an Astronomy, Forum, Prof. Fed Watson mentioned in passing the recent advances in technology that allows never before dreamed of results in the areas of amateur and professional astronomy and cosmology.  It seems difficult to believe that for thousands of years, the human race had such an extremely unrealistic view of the universe, and our place in it.  Yet, without the historically flawed models, the assumptions, and wildly mythological structures, much of what we take for granted today, might remain cloaked in mystery.  It is this human ability to build upon accumulated knowledge – sometimes renewed after a lengthy hiatus – or even transferred across racially differing societies – that facilitates genuine scientific progress.

Human curiosity is not culturally exclusive; from the earliest times, every culture, worldwide, has had some form of mythical version of the creation story.  Each ‘creation story’ mirrored the situation and society from which it originated; and each story symbolised the ‘supreme truth’ within its own society.  Scientific progress would not truly begin until many of these ancient traditions, bound up in folklore, superstition  and myth, started to decline. 

In trying to make some sense of order in the various models that have impacted the most on today’s perception of the universe, I think one of the earliest notable hypotheses is the ‘Mesopotamian Model’.  This model was developed by the inhabitants of the Nile and Tigris-Euphrates valleys.  The Earth was depicted as flat, and surrounded by lofty mountains.  The sky was a solid dome upon which the stars were placed, and water canopies emptied their rainfall.  The planets, the Sun and the Moon, were all imagined to be relatively small, and guided by celestial forces.  Interestingly perhaps, aspects of this model are offered in the Bible (Joshua 10 & Psalm 19). 

Whilst still containing strong mystical overtones, over time the Mesopotamian Model was adopted and modified by other civilizations.  Around the 6^th century BC early theorists such as Anaximander (possibly also the founder of evolutionary theory) and Xenophanes appeared on the scene, and whilst their explanations of the natural world were still far removed from modern ideas, they nevertheless did develop theories that didn’t rely on supernatural elements for support.  These ancient philosophers are recognised as the first true cosmologists, by virtue of the fact that they were genuinely concerned with the scientific study of the physical universe and its genesis.  The ancient Greek word – kosmeo – from which our modern word – cosmology – is derived, literally translates into - to order or to organise.

Every authentic scientific premise must make a prediction about the universe that can be measured and observed; history recognises Pythagoras as the man who made such scientific enterprise possible through mathematics.  His successors developed and enhanced his ideas, allowing science to become a sophisticated and authoritative discipline capable of some amazing early achievements.  Amongst these early achievements – without which later developments would have been impossible – were the measuring of the dimensions of the Earth – the Moon – and the Sun; and the distances between them.  To quote the author, Simon Singh: “these measurements were a milestone in the history of astronomy, representing as they do the first tentative steps on the road to understanding the entire universe.”

At this point it is worth taking a closer look at how some of these early measurements were achieved, and the human logic that lay behind such discoveries.  Aristotle (384 BC-322 BC) is acknowledged as being the first to write down a complete set of rules for logical analysis.  Whilst earlier philosophers had merely suspected the Earth was a globe – by drawing on their observations of the Sun and the Moon; Aristotle established these assumptions as fact.

  

He observed many eclipses, and obviously recorded his observations over time.  He noticed that during a lunar eclipse, the shadow of the Earth on the Moon was circular.  Naturally, a flat round object may also cast such a shadow.  However, Aristotle noted the shadow remained circular no matter in which direction the eclipse took place – in Aries, Capricorn, Gemini or Sagittarius.  It followed; the only object capable of casting a circular shadow from all directions is a sphere!   Thus, based on his empirical research, Aristotle affirmed the Earth was indeed spherical. 

Eratosthenes (276 BC-195 BC) is reportedly the first person to have used the word ‘geography’; he also ‘invented’ a system of latitude and longitude.  More impressively, he accurately measured the size of the Earth.  His measurement of about 39,250 km was accurate to 2% compared to modern measurements.  How he achieved this feat with the most basic tools available is testimony to human ingenuity. 

Whilst studying at a library, Eratosthenes learned of a water-well with extraordinary properties.  This well was situated near the township of Syene (near modern day Aswan).  Each year – at noon on the 21^st June – the day of the summer solstice - the Sun shone directly into the well, illuminating it right to the bottom.  Being an erudite chap, Eratosthenes realised for this to happen, the Sun must be directly overhead.  Eratosthenes, who resided in Alexandria, was aware that such an event didn’t happen in his locality.  Being aware of the Earth’s curvature, he reasoned that the Sun could not be overhead in Alexandria and Syene (several hundred km south) simultaneously; he decided to exploit his discovery in an attempt to establish the actual size of the Earth.  Today – we call this a ‘problem-solving approach’ – in which we take a problem and reduce it to simpler terms before making extrapolations to arrive at our final conclusions.

It is not within the scope of this article to explore too deeply how Eratosthenes arrived at his final results with little more than a stick and a brain; but by coordinating his readings to occur at the same time as the Sun was overhead and shining down the well in Syene, he placed a stick in the ground in Alexandria.  At the appropriate time, Eratosthenes recorded the angle of the shadow cast by the stick at mid-day.  Having established the size of the angle – 7.2° - the rest of the equation became academic.  Using the distance between the two towns, he extrapolated his results to estimate the distance around the Earth.  Having established the size of the Earth – it then became possible to estimate the size of both the Moon and the Sun – and their distances from Earth!

 

I can only reiterate this is: ‘a man – with a stick and a brain’!  Human resourcefulness leaves me quite flabbergasted – as does its frequent lapses in common sense!

In fairness to earlier philosophers, it was they who laid much of the foundations relating to the measurements mentioned above.  However, there was always one missing value – the size of the Earth.  Now this value was available, the remaining values were a matter of course.  Using Earth’s shadow cast on the Moon during a lunar eclipse, it didn’t take Eratosthenes long to estimate the Moon’s size as about one-quarter that of Earth.  Thus geometry, logic, and empirical research began to pave the way to genuine scientific discovery.  Measurements, sizes, distances, all relating to our own solar system became firmly established.  As indicated earlier, these measurements were remarkably accurate and have stood the test of time and advancing technology. 

Other suppositions being made about the universe at that time were not as accurate.  The influences of mythology and religion were, and still are, deeply entrenched in the human psyche.  These suppositions and the logic that lay behind them will be explored in later articles.

Refs:

Administrator, D. (2005, March 6). The ptolemaic system - a short history. Retrieved March 13, 2011, from The Flat Earth Society Forum: http://www.theflatearthsociety.org/forum/index.php?PHPSESSID=8c20b1a28c0eefa7dfb2f4a61e3326d5&topic=14.msg22#msg22.

Encyclopedia, W. T. F. (1999). Eratosthenes. Retrieved March 15, 2011, from Wikipedia: http://en.wikipedia.org/wiki/Eratosthenes.

JJ, O. E. A. (1999, January 1). Pythagoras of Samos. Retrieved March 14, 2011, from School of Mathematics University of St Andres Scotland: http://www-history.mcs.st-and.ac.uk/Biographies/Pythagoras.html.

Singh, S. (2005). Big bang. London: Harper Perennial.