Showing posts with label astronomy. Show all posts
Showing posts with label astronomy. Show all posts

Saturday, February 21, 2026

How Did They Know?

 


Each civilisation had a different way of looking at the stars. They found different patterns and linked them to a wide range of traditions, legends and stories. 

What is amazing is not the patterns but the level of detail they were able to observe in the night sky. A few years ago the jolly, ebullient Khurshed Batliwala gave a talk listing out a few things ancient Indian scientists observed and recorded - 

The Great Bear and Arundhati-Vashishta

The core pattern of this constellation is hard to miss. It looks like a giant kite with a long tail. The Greeks called it Ursa Major, the Great Bear, and saw a far more elaborate pattern - the quadrangle of the kite became the torso of the bear, the tail became its neck and head while the surrounding stars took the shape of a fat tail and spindly legs. 

Ancient Indians, on the other hand, focused on the core form and called it the "Sapta Rishi" - the seven sages - Bhrigu, Vashista, Angiras, Atri, Pulastya, Pulaha and Kratu. Of these Vashista is of special interest because the ancients noticed that this bright spot in the sky was not one but two different stars in close proximity - a double-star. They named the second star after the sage's wife, Arundhati. Each of these stars correspond to the following Arab-Greek equivalents:

Brightness of celestial objects is measured in Apparent Magnitude. This is on a reverse logarithmic scale, which means that the brighter an object is, the lower its magnitude number. In the Great Bear constellation, the brightest star is Alioth (mag 1.76 - 33rd brightest in the sky), followed by Dubhe (m 1.79), Alkaid, Mizar / Vashishta (m 2.23), Merak, Phecda, and Megrez. 

Note that Mizar / Vashishta is not the brightest, yet it is a well-known naked eye double star with the fainter star Alcor (Vashistha's wife, Arundhati - 'washed by the rays of sun'). This is the double-star, as Batliwala points out, that newlyweds in South India view formally because they rotate in perfect synchrony, and symbolise a balanced, harmonious, and lifelong marriage of mutual respect. References to this symbolic traditions are found in early Vedic literature, including the Rig Veda and especially the Brahmanas (like Taittiriya Brahmana). Out of the thousands of stars in the night sky how did the ancients decide to select this double star?

Batliwala goes on to describe other instances in ancient records and traditions that make us wonder about their perceptiveness:

  • The depiction of Varaha avatara in iconography carrying a round earth, long before the Egyptians of Greeks discovered that the earth was round;
  • Antares ("like-Mars"), the 16th brightest star in the sky was named "Jeshta" (biggest, eldest, oldest). How did they figure that this star is 40,000 bigger than the sun, ad one of the biggest stars known to man?
  • Rust-proof pillars - the one displayed in Delhi and another the Kollur pillar, said to have been built by tribals to welcome Adi Shankaracharya (8th century CE)
  • Metallurgy - Zinc extraction from ore was known for 4000 years . A difficult metal to extract because it liquifies at 997C and turns into gas at 1000C. So it had to be extracted within a 3 degree window. The ancients metallurgists did this by turning the furnace up-side down. This technology was copied by the Chinese and in turn, patented by William Champion (1709-89) in Britain
  • The value of Pi up to 30 decimals encoded in a Krishna sloka in the KatapayaSankhya format where numbers associated with alphabets: (eg., 1 = ka, ta, pa, ya)

Recently a few more examples turned up in a post titled, "How Much did the Ancients Know ? It’s fascinating". It records the work of one Dharampal (1922–2006), an Indian Gandhian thinker and independent historian who became known for re-examining India’s pre-colonial society using British archival records. 

Dharmpal notes that Hindu astronomers, many years BCE, represented the planets in ways that encoded precise astronomical knowledge. Jupiter was depicted with four dancing girls circling around it. Saturn was represented as a figure with seven arms, one of which grasped a ring. 

  • The Dancing Girls of Jupiter: Four moons of Jupiter were not known in Europe before 1609, when Galileo first observed them through his telescope. Even then, only the third and fourth satellites were occasionally visible to the naked eye, and only in the clearest atmospheric conditions. The fact that Hindu astronomical tradition represented Jupiter with exactly four attendant figures suggested a knowledge of these satellites that predated European discovery.
  • The Seven Arms of Saturn: Until 1783, European astronomy recognised only five satellites of Saturn. The sixth satellite was not discovered until 28 August 1789, when William Herschel identified it. The seventh satellite was observed by Herschel only after he had completed his grand telescope of forty feet focal length, and was first seen on 17 September 1789.

There is no mention of lenses or telescopes in the scriptures and records, so how did ancient Indians see and record details of celestial bodies with such amazing accuracy? 

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REFERENCES & LINKS

Katapayadi Sutra - https://www.eviolinguru.com/kadapayadi-sutra.html

https://en.wikipedia.org/wiki/Apparent_magnitude

https://en.wikipedia.org/wiki/Mizar

https://en.wikipedia.org/wiki/Alcor_(star)

How much did the ancients know? - https://substack.com/home/post/p-188261182 

Tuesday, July 12, 2022

Revisiting the Epics

I thought I knew a thing or two about Indian epics and classics.  Over the past months, two books and a podcast have undermined this notion, and reminded me that my knowledge is, at best, narrow and woefully shallow.

The two books were - S Jaishankar's "The India Way" and Roberto Calasso's "Ka: Stories of the Mind and Gods of India" (Translated by Tim Parks), and the podcast series, "The Vatapi Curry Point" by Krish Ashok and Anirudh Kanisetti.



Jaishankar's book is mainly about the evolving global stance of the Indian state - the way it views itself, and the rest of the world. Much of the book reads like a guide for career diplomats, but still, what is of interest in this context is Chapter 3, titled "Krishna's Choice". In this he lays out observations on India as a civilisational entity trying to fit itself into a narrower idea of a nation state, a concept born from the Peace of Westphalia - 'an international society of sovereign state entities possessing the monopoly of force within their mutually recognised territories'.

He begins with a quote (or admonition!) from Goethe -  "A nation that doesn't honour its past has no future", and discusses the importance of dissimulation in statecraft. While most of us may be familiar with Kautilya's 'Sama, Dana, Danda, Bheda' (alliance, compensation, force and trickery), as ways of approaching political challenges, the role of specific characters in the Mahabharata was something I did not know.

Take for instance, the role of Susarma. He was the chief of the Trigarta warriors from a kingdom around present day Punjab:

"Traditional allies of the Kurus, they conceived a special enmity towards Arjuna, who defeated them while preparing the ground for Yudhistira's coronation ceremony....their single-minded hostility proved very dear to the Pandavas. Constantly pouring oil into the Kaurava fire, they collaborated in the effort to smoke the Pandavas from the Virata kingdom during their period of exile...their challenge to Arjuna of a fight to the death diverted him away from the main battle, leading to the capture of his brother Yudhistira alive by the Kauravas...The moral here is of the danger of smaller adversaries whose single-mindedness goes to the extent of destroying themselves to inflict damage."

Obviously the reference here is to Pakistan and the state's attitude towards India. Jaishankar presents other examples as well:  Shalya, the maternal uncle of Pandavas, who is tricked by a false flag operation into committing to the Kaurava side; Krishna's brother Balarama, is genuinely neutral as he has taught warfare to both sides and opts out of the conflict by taking a long pilgrimage during the war; and Rukmi of Vidharba, another notable warrior who stays out of the war, by overestimating his own value to both sides and ends up accepted by neither.



Calasso's "Ka", on the other hand, examines the epics from a different dimension. While in Jaishankar's book we can connect to geographical locations that match places in India today, Calasso reminds us that the stars and constellations in their supra-human forms played an active role in the human drama, in this part of the world:

Daksha - "he who is skillful" - emerges from the thumb of the creator, Prajapati / Brahma's right hand. Over time, he becomes a king and weds Prasuti, and the couple have a whole bandwagon of daughters. 27 of these daughters marry Soma, the moon god, who places them in the heavens as dancing troop of 27 Nakshatras/stars. The most headstrong of his daughters is Sati who insists of marrying Shiva, the most reclusive and fiery-tempered of all gods; the one who traps the whole Milky Way (Akashaganga) in his tresses and brings it down to earth as the river Ganga!

The last one, a podcast, is delightfully irreverent. It is a freewheeling discussion on history, food, and science between two authors and social-media-stars, Krish Ashok and Anirudh Kanisetti on Instagram. It pokes fun at the prevailing dogmas, ridicules folks set on creating communal divisions while also asking interesting questions. 


Here is one: What is the similarity between Arjuna and Maradonna?

This question zapped me out for a while. How can there be anything in common between a hero of the epic Mahabharata and a modern football icon? Turns out that just like the tenuous but intriguing linkages brought out in the BBC series Connections 2 & 3,  the connection here too lies in something unexpected -  the metal Silver.

According to Krish Ashok, the Sanskrit name Arjuna is based on the Indo-European word for silver - "Argentum".  Arjuna - Argentum - Argentina - Maradonna!

There is certainly a lot more to the epics than meets the eye :)

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REFERENCES & LINKS

- Jaishankar, S (2021): The India Way

- Calasso, Roberto (): Ka - Stories of the Mind and Gods of India

- Vatapi Curry - Insta - https://www.instagram.com/_masalalab/?hl=en


Thursday, October 14, 2021

Orion and Friends



It's 5:30AM and there is a nip in the air. You look out from the balcony and your gaze moves up from the empty roads, the streetlights, over the tree-tops, to one single bright star in the sky.

Which one is it? you wonder..

As your eyes get accustomed to the darkness, other less bright stars peek out through the haze, and a familiar pattern emerges - the three stars that make the belt, two for the dagger, another two pairs each for the shoulders and limbs... and Orion the Hunter emerges in all its glory. Then again on either side of the hunter two more bright stars - Aldebaran and Sirius marking the positions staked by the constellations Taurus and Canis Major.


We are now the Navaratri festival season, a period of nine nights when the moon transforms from a thin sliver barely visible in evening sky, to a bright autumn full-moon marking, not only two of the most important festivals in India, Dussehra and Diwali, but also the onset of winter.

I often wonder - why are our night skies filled with stellar patterns that carry mostly Latin names, with a few Arabic ones thrown in for variety? What did the ancients in India, South America or Australia make of these patterns in the night sky?

As Raj Vedam explains so well in his videos, ancient astronomers in India looked at the skies in a very different way, with oral traditions that record and mark the changing positions of the moon, planets and stars with almost obsessive detail. So much so that with modern software simulations it is possible to triangulate the time-period of certain historical events that could only have happened thousands of years ago. 

The Ecliptic, or the path taken by the sun to traverse the sky, is one of the key reference points. They observed that - "The moon appears on the eastern horizon at a different time every day, offset by about 48 minutes, agains a different backdrop of stars." Also, it was noticed that it takes 28 days for the moon to return to the same backdrop of stars. From this emerged a system based on Nakshatras and Raashis.

Nakshatra refers to the principal or brightest star in each segment of the night sky, formed by dividing the ecliptic into 27 segments of 13.33 degrees (13.3 * 27 = 360). As a mnemonic to remember the right sequence these stars were woven into mythology to represent 27 wives of the moon.

Similarly the 12 lunar months were made by dividing the sky into 12 segments of 30 degrees each (12 * 30 = 360), represented by the constellation in which the full moon made its appearance. These were called the Raashis.

So when the full moon appeared in Chittira Nakshatra (Spica in Virgo Constellation) it could immediately be understood that in that month, the sunrise took place 180 degrees opposite in Ashvini Nakshatra (Sheratan or Beta Arietis in the Aries constellation).

What about old familiar friend Orion and his companions? For some reason it seems ancient astronomers in India were not too keen on conjuring up figures from the stellar patterns. They highlighted only three stars in the Orion and Taurus constellations:

One big surprise is that in the subsequent 13.3 degree segment they completely ignored the brightest star in the sky, Sirius and instead selected Pollux (Gemini constellation) as Nakshatra no. 7. To put this in perspective, Pollux  or Beta Geminorium is an orange giant with a magnitude (brightness) of 1.1 while Sirius (Greek for 'scorching' and also called Alpha Canis Majoris) has a magnitude of - 1.5 which is about 2.5 times brighter!

Maybe there is something more to this that I am missing, but ignoring the brightest star in the sky! - you can't be Sirius! 

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REFERENCES & LINKS

* Orion Constellation - ultimate guide - https://www.planetguide.net/orion-constellation/

https://www.astrosoftware.com/SiriusNakshatra.htm

* Inca Astronomy - https://www.peruforless.com/blog/inca-astronomy/


Thursday, January 14, 2021

Spin and Wobble vs. Space and Time

 Today is the winter equinox - one of the few festivals days linked to the solar calendar India. In the north - especially in Punjab the day is celebrated as Lohri, a harvest festival, while in the south and east it is Makara Shankranti.  

In the zodiac, Makara (crocodile), coincides with Capricon (sea-goat), and so this day marks the farthest movement of the sun on horizon, the longest night and shortest day of the year. From here on, as the sun moves further into Makara/Capricon, the days get longer, and winter is giving way to spring.

Indian astronomy is something I always wanted to understand better. No festival or ceremony - birth, marriage, death - is complete without a precise reference to the Hindu almanac which seemed like a complicated triangulation of the position of the stars, constellations, the sun and the moon. This is also the reason why most of us celebrate two birthdays every year - the constant solar calendar date, and the luni-solar date which changes each year.

It is only recently that I came across a video that explains some of these things clearly - a lecture by Prof. Raj Vedam titled, "Indian Civilization - The Untold Story". It is a long lecture (1:37 hrs) but what fascinated me is the explanation on astro-archeology. In this the author uses references to the luni-solar dates in the ancient epics and poems to determine when these works were composed.

First a bit of background. What is the Indian astronomical model? 

The main elements of the traditional astronomy are the Nakshatras and Rashis. The night sky was divided into 13&1/3 segments (Nakshatra s) and each was named after the brightest stars in that section. The 27 Nakshatras  covers the space around earth (27 * 13 1/3 = 360 degrees).

Next this was combined with the location of the full moon. So the sky was also divided into 30 degree segments called the Rashi -(30*12 = 360).

Now consider Kalidasa's epic poem, "Meghadoota" (The Cloud Messenger) which is said to have been composed in the 4th or 5th century CE. The story refers to a time when "the rainy season (Varsha Ritu) began in Ashada Masa". This means that at this time, the full moon was above Ashadha nakshatra (~Sagittarius constellation), and from here it follows that that the sun, 360 deg opposite, was in Punarvasu nakshatra (castor-pullox of Gemini).

At present the rainy starts when the sun is in MrigaShirsha nakshatra (Orion constellation). There is only one logical way to explain this discrepancy - precession of equinox.


What exactly is precession? It is the wobble of a spinning top. As the earth spins on its axis (once every 24 hours), it also wobbles slowly, making the axis turn a full circle in 25,771 years. Thanks to this wobble our view of the stars also changes as time goes by. Today Polaris is the pole-star (Dhruva today); in 3000 BC it was Thuban, and in 14000 AD it will be Vega (Abhijit).

So, coming back to Kalidasa's poem, it is precession that explains a two nakshatra difference between the observation of the start of the rainy season. Precession of equinox happens at the rate of 960 years per nakshatra. Hence the event being described by Kalidasa happened 1920 years ago (960 * 2), around ~100 CE about 400 years before the commonly accepted date of the composition!



This makes you wonder about conventional wisdom, most of which is based on the observations of Western scholars. Which are the other dates waiting to be revised in our textbooks? 

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REFERENCES & LINKS

* "Indian Civilization - The Untold Story" by Prof. Raj Vedam - https://youtu.be/RGyjvyXEKdc

* List of Nakshatras - https://en.wikipedia.org/wiki/List_of_Nakshatras

Tuesday, June 14, 2011

Starry, Cloudy Nights...


These days we have heavy rains interspersed with bright, burning sunshine. Tall cumulus clouds opening up into brilliant blue skies. At night, the same clarity now allows us to catch a glimpse of stars and constellations that would have been impossible to see a month earlier.

The problem with clarity, though, is that it brings up new questions! What, for instance, is that bright double star sitting next to Porrima in the Virgo constellation?

Traditionally, this season of heavy rains concides with the Malayalam month of "Edavam" (15 May - 14 June), which coincides with the Taurus sun-sign & constellation. While Taurus is aligned with the rising sun in the east, in this part of the world, it is Leo that is sitting right overhead, straddling the sun's elliptic path. So we start every evening with the brightest star on Leo - Regulus - and work backwards to the characteristic triangle Denebola & Zosma) that makes Leo's rear-side. Further north lies the Great Bear (Ursa Major) aka "Sapta Rishi" (7 great sages), with a double-star (Arundhati) marking the bend in its tail. And towards south is the Crux (Trishanku) hiding below the Centaurus.

Since Porrima's neighbor is not on the charts, it is, in all likelihood, a planet. Perhaps it is Saturn...or is it?

Thursday, November 04, 2010

Seeking Orion

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My anchor to the night-sky in Delhi, or for that matter anywhere else in India, has always been the `belt` of Orion the Hunter (aka Mriga in Indian mythology). The simple, staggered array of three bright stars (Alnitak, Alnilam, and Mintaka) could be spotted even when the sky was hazy...

Where should I look for the hunter in Tsukuba?

Here is the map for the Tokyo night-sky:

current night sky over Tokyo
Sky map by AstroViewer®

Since Tsukuba is close to Tokyo, perhaps the hunter is sitting somewhere along the edge of the eastern horizon...

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INTERESTING LINKS:

Your Sky from Fourmilab, Switzerland (lots of great science stuff here!)
- Horizon view of Tokyo (35°45'N 139°34'58"E)

Stellarium - free, open-source planetarium downloads

AAAD - Amateur Astronomers Association Delhi - http://www.aaadelhi.org/

AstroViewer - (pretty basic, with limited locations, but the maps can be embedded)