Why are we fascinated by astronomy?

Sunday, 19 January 2014 - 11:32am IST | Agency: DNA
Dr Mayank Vahia explores why astronomy holds such a grip on the human imagination, and how the study of this subject has evolved since the dawn of human beings.
  • RNA Research & Archives

Everyone knows a bit of astronomy. Indeed, amongst all the sciences, astronomy has more followers than any other field. There are few followers of biology, or any branch of physics or chemistry, but almost all major cities have at least one amateur astronomy club. NASA even has a TV channel of its own. As a subject of no direct utility, this is an impressive achievement.

So why are we so fascinated by astronomy?

Why does astronomy hold such a grip on human imagination, and why do scientists pursue it with such vigour? Why do nations invest so much money for research in astronomy?

Astronomy is certainly fascinating. To think beyond ourselves and our Earth, to reach the truly unreachable has a certain fascination. But astronomy did not begin for such lofty purposes.

For a long time, humans considered the sky to be an integral part of the Earth, a sphere that existed around our planet but which was less rigid than our own. In the sky, about a dozen wanderers were allowed to, well, wander within some confines. The rest of the stars were stuck to a sphere that rotated at a speed slightly less (by four minutes a day) than the rotational speed of the Earth.

But this idea also came much later. The earliest idea was completely different.

In the first philosophical world view, the Earth was the mother. And like a good, loving mother, she provided us with all of our needs. Some of the earliest human habitats have been found deep inside caves. Some believe this is because caves gave us a sense of living inside the womb of mother Earth. A lot of the earliest human art can be found inside deep caves as well. Books like The Mind in the Cave: Consciousness and the Origins of Art by David Lewis Williams provide a compelling account of the human fascination for caves.

Rains are a big factor in Mother Earth providing us with our needs. And this link between rains from the sky making Mother Earth fertile had an obvious symbolic connotation. Hence, with Mother Earth came Father Sky. The father, aloof, guiding, and fertilising Mother Earth to provide all beings with life-nurturing necessities. So the earliest symbolism amongst humans consists of female figurines with exaggerated feminine features that seem to represent the all providing Mother Earth.

The most conspicuous feature of the sky is, of course, the Sun, the majestic ruler of the sky. All cultures and civilisations paid their respects to this mighty giver of warmth. The Sun was so powerful it made the stars vanish when it was in the sky, and provided us with much needed light and warmth.

But very quickly we realised that, somehow, the Sun was not that powerful. Somewhere along the line, the Sun seemed to be under the influence of other forces. It rose in the eastern direction and set in the western direction, but the sun could rise between far north of east and the far south of east over one year. In other words, the rising and setting points of the Sun seemed to move in a north-south cycle over approximately 365 days, when it returned to the same point. This compulsion imposed on the Sun somehow demoted its status as the primary all-controlling God to just an important god who could be controlled by others.

The other important object in the sky, the Moon, was somehow related to the Sun. In the sky, the farther it was from the Sun, the brighter it became. Humans the world over tried to explain this in a variety of ways, from a full cup being emptied by the Sun, to a god cursed into a waxing and waning cycle.

All in all, it was clear that these gods were important but not primary. Somehow they seem to be controlled by others more powerful than themselves.

About 400 years ago, we began to appreciate that the Sun is in fact, the ultimate god, and that it is not the Sun that is being forced to move north and south but it is the angle of the Earth’s rotation that is doing this. And in terms of stabilising the Earth’s movement, the Moon is indeed the most important object, and therefore the second most important ‘god’. Clearly, as far as myths and mythologies are concerned, science had taken us back – it admitted of only the Sun and the Moon as important extra-terrestrial controllers of life on Earth, which are too powerful for humans to influence!
 
As human studies of the sky improved, it became clear that the sky was not a fixed sphere somehow connected to the Earth, and the twinkling sources of light in the night sky were not fixed illuminated points. The sky was active and dynamic. There was thunder, lightning, moving clouds, and stars that seem to change every night over the year.

In order to keep track of the night sky, people divided it into different join-the-dots patterns that were easy to remember. A large fraction of the constellations that we know today were proposed by the Sumerians some 5,000 years ago and adopted by others. Different cultures gave minor twists to these, based on how the patterns appeared to them and how their myths best fitted the sky.

In India, the Moon was the primary source of our calendar, and the Lunar Mansions – the Nakshatras – hold more powerful imagery in our mythology. Several Indian tribes have their own constellation patterns. Once constellations became the bench mark of studies, a truly systematic study of the skies – the subject of astronomy – began.

This gave new direction to human imagination, with new cosmogonies – ideas about the Universe and our place in it. What is the Earth? How is it held up? What surrounds the Earth? What is the relation between the Earth and the gods? Who all are represented in the sky? How did the Earth and all life come into being? All these questions began to be answered with ever increasing fascination and complexity.

Amongst all these, my favourite is the Nasadiya Sukta, which reads as follows:

(Nasadiya Sukta; Rig Veda X, 129)

1. At first was neither Non Being nor being.
There was not air nor yet sky beyond.
What was its wrapping? Where? In whose protection?
Was water there, unfathomable and deep?

2. There was no death then, nor yet deathlessness;
Of night or day there was not any sign.
The One breathed without breath, by its own impulse.
Other than that was nothing else at all.

3. Darkness was there all wrapped around by darkness,
and all was Water, indiscriminate.
Then, that which was hidden by the Void, That One, emerging
stirring, through power of Ardour, came to be.

4. In the beginning, Love arose,
Which was the primal germ cell of the mind.
The seers, searching in their hearts with wisdom,
Discovered the connection of Being with Non-being.

5. A crosswise line cut Being from Non-being,
What was described above it, What below?
Bearers of seed there were and mighty forces,
Thrust from below and forward, move above.

6. Who really knows? Who can presume to tell it?
Whence was it born? Whence issued this creation?
Even the Gods came after its emergence.
Then who can tell from whence it came to be?

7. That out of which creation has arisen,
Whether it held it firm or it did not,
He who surveys it in the highest heaven,
He surely knows – or maybe He does not!

I have taken the translation from Panikar’s Vedic Experience. It is one of the most ancient texts of Hinduism, and contains within it a whole host of religious concepts that would be debated in detail in later literature. Within this poem are the roots of the ideas of the ultimate indefinable god, the finiteness of time, the idea of the birth of gods, the original Hiranyagarbha – the golden egg that created life, and many more. One can only marvel at this flight of imagination at a time when we knew nothing of the Big Bang or of the evolution of time and the universe.

Once our understanding reached this level, two different groups of star gazers arose. One was the farmers, who used it to decide on the upcoming season of rains and the best time for sowing seeds. The others were the soothsayers who made a fortune predicting other people’s fortune!

The sky was for astronomers and astrologers alike. Astronomers used it for a variety of reasons, such as making calendars and navigational charts. Their work overlapped with that of astrologers in defining the auspicious moments a particular activity could be carried out – from prayers and havans, to when a man and a woman should first hold hands and take their vows of marriage in front of the gods.

However, the fact that astronomers, at least in India, were not particularly fond of astrology – which was of Yavana or Greek origin – can be seen from the manner in which Varahamihira (in Bruhad Samhita, 505 AD) defines what an astronomer should be able to do:

* Time division of Yugas, years, solstices, seasons, months, fortnights, days, nights, and smaller time units, and their start and end times
* Saura (the planetary calendar including the retrograde motion of planets and their different speeds in the sky),
* Savana (terrestrial calendar)
* Understand and calculate solstices
* Calculate times of eclipses
* The celestial sphere and understand Nakshatras, zodiacs and constellations and show them in the sky
* Annual motion of the Sun and difference in the lengths of day and night
* Calculate latitude and longitude of a place (from Ujjain)
* Teach this to a learned person

I have taken the translation from Indian Astronomy: A Source book by Subbarayappa and Sarma published by the Nehru Centre, Mumbai. Note that in this listing, no knowledge of astronomy or ability to predict anything beyond calculating the tithis is needed. Clearly, astrology was not on the syllabus for being an astronomer.

So there was a period in human civilisation where amateur astronomy amounted to looking at pretty patterns in the sky, recalling various myths associated with these patterns, and predicting the seasons. For the professional, it included calculating various parameters listed out by Varahamihira and checking them against observations.

Theoreticians of that time worked on these empirical formulae and tried to see if they could be fitted into some model. The most common approach was epicycles, where the planets moved around the earth in one cycle and around the locus of the circle in an additional circle to produce the observed features. With more data, they became increasingly complex until Newton and Kepler made the solar system heliocentric rather than Earth-centric. It was only then that mathematics made the underlying principles elegantly simple.

All this changed once the telescope was invented. Then all hell broke loose. Galileo showed the moons of Jupiter’s going around Jupiter and angered a lot of people by suggesting that we (on the Earth) may not be the centre of the Universe. From there on, things only became worse for the human ego. Today, we know the Earth as just the third big rock from the Sun. The Sun is a rather run of the mill star – just one of the trillions of stars in our galaxy. Our own galaxy is a rather common variety galaxy in the Universe that has billions of galaxies. We call it the Milky Way because it appears as a milky band in the sky – if the Gonds had their way, it would be called “a pathway of animals”, and in Sanskrit we would call it the Akash Ganga.

Astronomy in the 21st century is, of course, very different. Using electromagnetic radiation, radio waves and gamma rays, and beyond that to neutrinos and particles, the insights that we have gained into the zoo of celestial bodies in our universe is very different. These gigantic objects with their own control on space and time, their beginning and their end, make the story of astronomy today far more exciting. But we will leave that for another time.

 

Dr Mayank Vahia is a scientist working at the Tata Institute of Fundamental Research since 1979. His main fields of interest are high-energy astrophysics, mainly Cosmic Rays, X-rays and Gamma Rays. He is currently looking at the area of archeo-astronomy and learning about the way our ancestors saw the stars, and thereby developed intellectually. He has, in particular, been working on the Indus Valley Civilisation and taking a deeper look at their script.


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