Friday, October 2, 2015

How many types of number systems do you know?

How many types of number systems do you know?

Usual answer is

1. Roman numerals
2. Arabic numerals (wrongly called so of course, as they originated in India)

Ancient Indians are credited with invention of the decimal number system, place value system and zero (with its properties). Indians were also familiar with negative numbers and properties of infinity (seen in Yajur Veda and also Buddhist and Jain literature). Indians were very adept at dealing with fractions and had a very accurate calendar too. They needed the accurate calendar for the purposes of navigation. Since the Mauryan times, India had 1000s of merchant ships sailing in the Indian ocean.

Sanskrit  language has words for very large numbers (due to lot of work done in astronomy). Most Indians are familiar with lakh, crore, …but the numbers are named up to 51st power of 10 and also in some cases up to even larger numbers.

Such large numbers were necessary because Indian astronomers counted time in terms of astronomical events.

 There are 3 types of number systems used in Indian mathematics:

Bhutasamkhya system- earliest
Aryabhata’s system
Katapayadi system

In Rigveda, numbers are referred in words.

Bhutasamkhya is a method of recording numbers using ordinary words having connotations of numerical values. For example the Sanskrit word for ‘eye’ or ‘hand’ or ‘ear’ would denote 2, that for ‘finger’ would denote 10. Since Sanskrit is very rich in synonyms, mathematical formulae could be expressed in a poetic fashion by using this system. So instead of having separate names for the digits, ordinary words could be used.

The Āryabhaṭa numeration is a system of numerals based on Sanskrit phonemes. The digits are represented using consonants, place values are represented using vowels. It was introduced in the early 6th century in India by Aryabhata, in the first chapter titled Gītika Padam of his Aryabhatiya. It attributes a numerical value to each syllable of the form consonant+vowel possible in Sanskrit phomology, from ka = 1 up to hau = 1018. Aryabhata’s system however made the numerals into words that were sometimes very difficult to pronounce.

Katapayadi System: There is a many-to-one mapping between consonants and a number. For example ka, ta, pa or ya…any of these can be used to represent the number 1. Kh, tha, pa or ra represent 2 and so on. All stand-alone vowels represent the number 0. The system has a few more complications and details are covered in the attached lecture.

For anyone interested in Mathematics, the whole lecture series is a must-watch.


Lastly…

The significance of the development of the positional number system is probably best described by the French mathematician Pierre Simon Laplace (1749–1827) who wrote:
It is India that gave us the ingenious method of expressing all numbers by the means of ten symbols, each symbol receiving a value of position, as well as an absolute value; a profound and important idea which appears so simple to us now that we ignore its true merit, but its very simplicity, the great ease which it has lent to all computations, puts our arithmetic in the first rank of useful inventions, and we shall appreciate the grandeur of this achievement when we remember that it escaped the genius of Archimedes and Apollonius, two of the greatest minds produced by antiquity.