Jyotish. Andrew Mason

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СКАЧАТЬ asks the question, ‘Is the axis of the Earth’s spin wobbling or is the whole orbit wobbling?’ In other words he seems to be asking: if the other planets (or for that matter any orbiting body) have nodes, shouldn’t the Earth have nodes33 also? Tobey had never encountered an astronomer who had considered the possibility of Earth nodes, but makes the observation that all ellipses are essentially epicycles or small orbits and that by moving in two different circles simultaneously a planet (or satellite) will automatically describe an ellipse (see diagram).

      Here the black dot (representing Earth) orbits the Sun in a counter-clockwise direction. In moving from position 1 to 2 it travels 15° about its great solar orbit whilst simultaneously moving 15° anticlockwise within its lesser orbit. At position (7), 90° of both orbits have been completed by Earth and here it drops maximally inside its great solar orbit. At position (13) Earth is again synchronous with its great solar orbit, having moved 180° in both orbits. At position (19) 240°, Earth again moves maximally inwards on its lesser orbit. In returning to position (1) Earth finalises its great orbit but imperceptibly completes its lesser orbit ahead of the former – making its now elliptical orbital plane appear to precess, that is, slip backward. If we accept this precessionary model, Earth would begin its next great orbit 50 arc seconds back (or clockwise) from position (1), meaning that its polar axis would continually precess in seconds of arc with each successive solar orbit, which is exactly what we see at the spring equinox each year.

      Tobey notes that to be a perfect ellipse the revolution of both orbits must be identical; however, planets and satellites do not move in perfect ellipses, hence they move in regressive ellipses. He also makes the observation that the elliptical shape of Earth’s orbit is being somehow mirrored by Earth’s ellipsoid profile, having a polar diameter of 7901 miles with a girth of 7926 miles (a difference of 25 miles). Lastly, special note should be made of the influence exerted by our rather unique (and intimate) companion the Moon, which is proportionally far larger than any other satellite (to its primary) in our solar system.

1.6 CALENDAR REFORM COMMITTEE

      Note: This section concludes the information previously outlined in Section 1.3.

      We are not aware how the Hindu savants determined Dhṛuvaka (polar longitude) and Vikśepa (ecliptic latitude), it appears they had a kind of armillary sphere with an ecliptic circle which they used to set to the ecliptic with the aid of standard stars like Pushya (δ Cancri), Magha (α Leonis), Chitrā (α Virginis), Vishaka (ι Libræ), Shatabhishak (λ Aquarii) and Revati (ζ Piscium).

      Saha and Lahiri (1992)

In an effort to unify India’s many regional calendars,34 November 1952 saw an appointment of a Calendar Reform Committee or CRC whose principal task was ‘to examine all existing calendars being followed by the country and after scientific study of the subject submit proposals for an accurate and uniform calendar for the whole of India.’

Any reformed dates were then hoped to be adopted for both civil and religious purposes, ratifying the country’s numerous festivals, luni-solar calendars, Panchāng35 and of course Ayanāṃśa. Though not directly incorporating Christian/Gregorian or Islamic considerations,36 some indirect study of these calendars was also included.

The Calendar Reform Committee, chaired by Professor Meghanad Saha, comprised seven members37 hailing from varied backgrounds in higher education and the sciences. Together they laboured over the task for about three years, finally submitting their 279-page report to the Council of Scientific and Industrial Research (CSIR) in 1955.38

N.C. Lahiri, whose surname ultimately hijacked Chitrāpakṣa39 (now popularly referred as Lahiri Ayanāṃśa), was one Sri Nimal Chandra Lahiri, then acting secretary of the committee. As well as being a meteorologist, Lahiri was by all accounts something of an astrologer/astronomer as well as (and most interestingly) a publisher of ephemerides.

During the course of investigation into ancient Indian calendrical systems, the committee considered modern astronomical data as well as examining a large number of classical works including Siddhântic and Vedāṅga Jyotish.40 Although concluding that ‘no definite values on the initial point of the zodiac’ were to be gleaned directly from the latter’s pages, it was felt the location of 0° might be inferred from the positions of junction stars (Yogatârâ) as presented in Chapter VIII of the Sûrya Siddhânta (generally agreed to be an authoritative and accurate Siddhântic work). Indeed, this text was to become their principal guide during the investigation. In the words of the committee: ‘Our modern Sûrya Siddhânta is a book of 500 verses divided into 14 chapters… A scrutiny of the text shows that it is, with the exception of a few elements, almost completely astronomical.’41

1.7 WHY CHITRĀ?

While attempting to uncover a true measure of ancient astronomical calendars, it soon became apparent that previous researchers had hit a similar impasse, concluding the initial point of the zodiac to be close to Revati’s Yogatârâ (ζ Piscium), situated at 359° 50′ Pisces, yet the absence of a ‘prominent’ star marking this critical juncture had also prompted the question, could another Yogatârâ have been used indirectly to infer this auspicious point?42

Directly opposite the Revati/Ashwini juncture lies Chitrā Nakshatra (23° 20’ Virgo – 6° 40’ Libra). Its Yogatârâ Chitrā/α Virginis is given a longitude of 180° (0° Libra) by Sûrya Siddhânta. Situated about 2° below the ecliptic with an impressive 0.9 Mv (magnitude), Chitrā is the 15th brightest in the northern hemisphere.43

      Had Chitrā been considered fiducial, it only remained to calculate the coincidence of this Yogatârâ with the autumnal equinox and infer the initial point of the zodiac. This, you might think, neatly wraps up the matter on two counts: first, Chitrā’s rather exacting degree of longitude; and second, having such data endorsed by an esteemed Siddhânta, adding legitimacy to the whole proposal. However, the referral star idea is not without controversy!

      Solstices and equinox as of ad 285, Chitrā Yogatârâ (α Virginis) providing the referral point for Chitrāpakṣa Ayanāṃśa.

1.8 CONTROVERSIES

The astronomical classics use a number of techniques to determine the positions of stars and the one favoured in our surviving44 version of Sûrya Siddhânta is known as Dhṛuvaka. This system of measurement we now interpret as polar longitude. Converting this measurement into something akin to a modern reckoning adjusts the longitude of Chitrā/α Virginis to 180° 48′ 48″ (a difference of almost 1°), a discrepancy noted by the CRC45 yet curiously put aside in their final deliberations.

Added to this there is a lack of corroborative evidence within the Indian astronomical tradition of Chitrā serving as referral star for the initial point. There are also the contemporary Siddhântic works such as Brāhma Spuṭa,46 ŚiromaniСКАЧАТЬ