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Dhvāntapramāpaka-yantra (ध्वान्तप्रमापक-यन्त्र): Spectrometer and Prakāśastambhanābhidalauha (प्रकाशस्तम्भनाभिदलौह): Novel material

Amśubodhinīśāstram (अंशुबोधिनीशास्त्रम्):

Amśubodhinī of Maharṣi Bharadvāja (महर्षि भरद्वाज) is a work of the Sūtra period, with a commentary by Bodhānanda (बोधानन्द). In the original text of Amśubodhinī, the aphorisms are divided into 12 chapters having 1000 sections. A manuscript of the first chapter with the first fifty aphorisms and their commentary under the title ‘Sṛṣṭyadhikāraḥ (सृष्ट्यधिकारः)’ which translates as Evolution of the Universe is available in the Oriental Learning Institute of Baroda. The ‘Sṛṣṭyadhikāraḥ’ describes the details of the evolution of the Universe from the Big Bang to the  evolution of our Solar System. A copy  of this manuscript was researched and studied by late Dr. Narayan Gopal  Dongre and Dr. Shankar Gopal Nene. In Amśubodhinī, there is evidence to bear out that some considerably complex instruments and tools existed in ancient India. One of them was ‘Dhvāntapramāpaka-yantra’ which is known as spectrometer in the modern context. Late Dr. N. G. Dongre devised this spectrometer in 1993 in the BHU, Varanasi, according to the methodology and process described in the Sūtras (सूत्र) of Bharadvāja and as elucidated by Bodhānanda. Ancient India was advanced in the field of metallurgy. One can see such descriptions given in various ancient scriptures. In this context, the synthesis of a special material ‘Prakāśastambhanābhidalauha – Infrared transparent Material of range 5000 cm -1 to 1400cm -1 , is extremely significant. This material was synthesized by Dr. Dongre at the National Metallurgical Laboratory (NML), Jamshedpur in 1998 with the help of the then Director of the NML and Dr. Dongre’s colleagues. Both the material and the spectrometer, developed through research are not only unique in their functionality, but also indicate the in-depth knowledge ancient Indians had in material science and other branches of science. For this unique contribution, Dr. Dongre was felicitated and conferred the “Ceramics Award” by the Ceramic Society of India, New Delhi.

Dhvāntapramāpaka-yantra (Spectrometer):

In ancient India, spectroscopy (dhvāntavijñāna, ध्वान्तविज्ञान) was an important method to reveal the secrets of the universe and to understand the process of evolution. The spectrometer is used in spectroscopy for producing spectral lines and measuring their wavelengths and intensities. Both Bharadvāja and Bodhānanda have given descriptions for devising such a spectrometer which was used for analysing and probing the creation of different star-systems. From the description of the instrument it is easy to infer that the Dhvāntapramāpaka-yantra is probably one of the five devices that were used to measure the spectra of the three optical regions. The Dhvāntapramāpaka-yantra as described by Maharṣi Bharadvāja, is a sophisticated instrument – a spectrometer, used to measure the full range spectral radiations (dhvānta, ध्वान्त or tama, तम). The three optical regions of tama – infrared, visible light and ultraviolet regions are called tama, gūḍhatama (गूढतम) and andhatama (अन्धतम), respectively. The commentary of Amśubodhinī also mentions that these are known as rajas (रजस्), tamas (तमस्) and sattva (सत्त्व) respectively in the philosophical texts. In astrophysics the Dhvāntapramāpaka-yantra was used for the spectral classification of stars or Nakṣatra (नक्षत्र). This instrument was able to measure the Fraunhofer lines (spectral absorption lines) present in the visible region of solar spectrum. The text of the Amśubodhinī enumerates various radiations (tama) with their symbolic names (sāṅketa सङ्केत). It also gives the measurements of the radiations expressed in terms of ancient unit of angle – kakṣya (कक्ष्य) (1 kakṣya = 10 -4 radian), related to their corresponding deviation produced due to dispersion through the prism. It is interesting to note that as the ‘radian’ word is derived from radius, similarly ‘kakṣya’ appears to have been derived from the word ‘kakṣa (कक्ष)’ the orbit. In the work ‘Yantra Sarvasva (यन्त्र सर्वस्व)’, Maharṣi Bharadvāja described the Dhvāntapramāpaka-yantra as the 109 th instrument comprised of 32 ancilliary components, capable of analysing radiation in general. According to Śārikānātha (शारिकानाथ, 780-825 CE), writer of Dhvāntavijñānabhāskara (ध्वान्तविज्ञानभास्कर), which is based on Yantra Sarvasva, 13 out of the 32 components are sufficient to analyse tama, the radiation of the optical region. From the analysis of data of the Dhvāntapramāpaka-yantra, it was concluded that:

  1.  The special vertical design of the spectrometer is suited to gather the radiation from solar and other stellar sources.
  2.  The wavelengths corresponding to the kakṣya data fairly tally with that of Fraunhofer’s lines from A to K covering almost the whole visible range of solar radiation – Alika (अलिक) as A, Biṁboka (बिंबोक) as B, Vīchaka (वीछक) as C, and so on.
  3. The format of symbolic names (sāṅketa) is parallel to the modern spectroscopic classification of star types. The details of these components, spectroscopic data provided by Dhvāntapramāpaka-
    yantra, the prism setting, and derivation of formulae are available in the book Amshubodhini shastram by Dongre-Nene and articles published in Indian Journal of History of Science.
Prakāśastambhanābhidalauha: Novel Infrared Transparent Material:

The synthesis of materials or alloys required to prepare the prism and lenses for different spectral regions and wavelength ranges of the spectrometer was known to the people of ancient India. The names of materials such as Uśṇāpahāraka-lauha (उष्णापहारक-लौह), Chāyā- prabhāvibhājaka-lauha (छाया प्रभाविभाजक-लौह) and Prakāśastambhanābhidalauha, etc. are cited in Amśubodhinī.
One of these materials – Prakāśastambhanābhidalauha (visible light absorbing material), unique, non-hygroscopic infrared transparent material of range 5000 cm -1 to 1400 cm -1 was prepared at NML, Jamshedpur. According to the Sanskrit text, this material should be able to absorb visible light and will transmit infra-red radiation.

The composition of constituent raw materials mixed together in ratio as described in the text was melted at a temperature of ~940 o C and then rapidly poured into a dye cast to produce a non-opalescent greenish yellow calcium glass. This material, used for creating the windows ( this is serious error) and prisms, is unique in the sense that it is non- hygroscopic. Most of the known infra-red transparent materials, e.g. LiF (lithium fluoride), CaF 2 (calcium fluoride), used for prisms and windows for cells are hygroscopic in nature and need dry air working environments. These materials lose their infrared transparency in presence of moisture, whereas the novel material retained its properties despite such conditions. It was also resistant to rust. It is important to note that this material was synthesized according to the methodology and process given in the Sūtras of Bharadvāja in Amśubodhinīsastraṁ.

The interpretation of the first chapter of Amśubodhinī along with detailed process of construction of the spectrometer, and laboratory preparation of the novel material is available in the book “Maharṣi Bharadvāja’s Amśubodhinīsastraṁ: Cosmology and Physics of Nuclear Particles in Ancient India: A Book of Modern Physics and Technology” by Dr N.G. Dongre and Dr. S. G. Nene, Triangle Concepts, Pune, 2010.