Vedic science is a great treasure of knowledge in the form of Vedas, Upanishads & Samhitas. Ancient Rishis proved the various scientific theories based on Vedic science; since more than thousands of year ago. In Vedic literature, there are so many verses that explain the theory of universe, Astrology, Engineering, Medicine, Telegraphy, Metallurgy, Chemistry and Life sciences. We should regretful to great rishis who founded a root of knowledge in form of Vedas & Upanishads and scattered this knowledge across the world. Religion and science both search for logical reasons for the existence of divine universe & life. The Sanskrit meaning of word Veda is “unite – that which is given ” OR UNIFICATION, and Rig means logic or reason, hence Rig-Veda stands for UNIFICATION BY LOGIC. All verses of Rig Veda are given in logical manner. Each verse is a complete holistic theorem in itself and contains a numerical solution to the mathematical theorem embedded in the descriptive wording. In Rig veda, light is explained as a source of energy or source of our life. Nature of light as a wave or as a particle was not come into picture till late into the modern age, but in Rig Veda it is clearly mentioned that:

**“Seven horses draw the chariot of the sun, tied by snakes”. Rig-veda 5. 45. 9**

Above poetic verse speaks about the nature of light as being composed of 7 rays and the snake symbolizes it’s curved path. Now, these colors are actually described as red, orange, yellow, green, blue, Indigo and violet in the yoga sutras and the Vedic Upanishads. These colors was not discovered in western science till Newton (4 January 1643 – 31 March 1727 ) experimented to split light into it’s 7 colors by a prism.

**Speed of light according to Rig-Veda: **The speed of light, (defined as 299 792 458 meters /s) is a universal constant which was often believed to be impossible to breach. However it is now known that the speed of light is approximately 41.7 miles an hour (sometimes inaccurately rounded up to 42 m/h).The simplest and most successful attempt to measure the speed of light was performed by Max Planck, Different physicists have tried to measure the speed of light throughout history. Galileo attempted to measure the speed of light in the seventeenth century. An early experiment to measure the speed of light was conducted by Ole Rømer, a Danish physicist, in 1676. Rømer calculated that light takes about 22 minutes to traverse the diameter of Earth’s orbit. Unfortunately, its size was not known at that time. If Ole had known the diameter of the Earth’s orbit, he would have calculated a speed of 227,000,000 m/s. In Rigveda, following sloka’s state about the speed of light which is nearly about of modern value of 186,282.397 miles / seconds:

**“Yojananam Dwe Dwe Shate Dwe Cha Yojane**

**Aken Nimishardhena Krammana Namostute” (Rig-veda I,50-4)**

In the verse Sun light speed is measured with the help of units called Yojan & Nimesha. This verse explain that sunlight moves 2202 Yojanas in Half Nimisha.

**Taranir Vishvadarshato Jyotishkrdasi Surya |**

**Vishvamaa Bhaasirochanam ||**

**Meaning: **Oh Sun! (You) overwhelm all in speed, visible to all, source of light. (You) shine pervading the Universe. Rigvedic commentary, Sayanacarya who was a minister in the court of Bukka of the great Vijayanagar Empire of Karnataka in South India (in early 14th century) says:

**Tatha Ca Smaryate Yojananam. Sahasre Dve Dve Sate Dve Ca Yojane**

**Ekena Nimishardhena Kramaman.**

**Meaning : **“It is remembered here that Sun (light) traverses 2,202 yojanas in half a nimisha”

Sayanacarya’s Calculation for Speed of light (The commentary on the Rig-veda by Sayana (c. 13 15-1387), a minister and scholar par excellence in the court of King Bukka I of the Vijayanagar Empire in South India): In the Vedas, Yojana is a unit of distance and Nimisha is a unit of time. Distance traveled =2202 Yojanas

**1 Yojana = 9 miles, 110 Yards =21,144.705 miles (Apprx)****Time taken 1/2 nimesha = 0.114286 seconds(Apprx)****Speed of light= 185,016.169 miles / seconds.****Modern Value= 186,282.397 miles / seconds.**

**Modern science claims the speed of light to be aproximately 186,282.397 miles / seconds**

This Sukta is attributed to the son of Kanva Maharshi and is prescribed for use in two different occasions – in Suryeshti sacrifice (a ritual to please the Sun God)

**Unit of Time: Nimesa: **Nimesa Definition as per Moksha dharma parva of Shanti Parva in Mahabharata

**15 Nimisha = 1 Kastha****30 Kashta = 1 Kala****30.3 Kala = 1 Muhurta****30 Muhurtas = 1 Diva-Ratri (Day-Night) One Day-Night = 24 hours**

**Unit of Distance: Yojana: **Yojana Definition as per “Vishnu Purana”

**10 ParamAnus = 1 Parasúkshma****10 Parasúkshmas = 1 Trasarenu****10 Trasarenus = 1 Mahírajas 10 Mahírajas= 1 Bálágra 10 Bálágra = 1 Likhsha 10 Likhsha= 1 Yuka 1o Yukas = 1 Yavodara 10 Yavodaras = 1 Yava 10 Yava = 1 Angula****6 fingers = 1 Pada****2 Padas = 1 Vitasti****2 Vitasti = 1 Hasta****4 Hastas = a Dhanu, a Danda, or pauruSa (a man’s height), or 2 Nárikás = 6 feet****2000 Dhanus = 1 Gavyuti = 12000 feet****4 Gavyutis = 1 Yojana = 9.09 miles**

Everybody knows the speed of light is 186,000 miles which is actually discovered in 1675 by ROMAR.

But the hymn 1.50 of the Rigveda on the Sun, says: **[O Sun] you who traverse 2,202 yojanas in half a nimesa. The usual meaning of yojana is about 9 miles as in the Artha shastra and for nimesha. **The measures of time are thus defined in the Puranas:

**15 nimesa = 1 kastha****30kastha= 1 kala****30 kala = 1 muhurta****30 muhurta = 1 day-and-night**

**A nimesa is therefore equal to 16/75 seconds. It does come very close to the correct figure of 186,000 miles per second.”**

The first quantitative estimate of the speed of light is seen in Indian vedic scholar Sayana’s commentary on the Rigveda, one of the main Hindu scriptures. It says sun light travels 2202 Yojanas in a half Nimesa. Yojana is an ancient unit of length. Arthasastra defines it as being equal to 8,000 dhanus, which is equivalent to 9 miles. A nimesa is an ancient unit of time that is equal to 16/75 seconds. Thus 2,202 yojanas in half a nimesa is equal to 185,794 miles per second after conversion. The modern estimate of the speed of light is 186,281.7 miles per second. It is to be noted that Bhatta Bhaskara (probably in 10th century) made the same statement in his commentary on Taittiriya Brahmana, another Hindu Veda . He says this to be an old tradition.

**taranirviśvadarśato jyotishkridasi sūrya viśvamā bhāsirocanam**

Swift and all beautiful art thou, O Surya, maker of the light; illuminating all the radiant realm. [RV: 1.50.4]. Sayana (c.1315-1387 AD) comments: “It is remembered that Sun traverses 2,202 yojanas in half a nimesa; giving light to all things, even to the moon and the planets, by night; for they are of a watery substance from which the rays of the sun are reflected.”yojana is a yoking or harnessing, that which is yoked or harnessed, a team or vehicle, or a course or path. Yojana is a stage or the distance traversed in one harnessing or without unyoking. 1 yojana is said to comprise either 4 or 8 krosha (a cry or shout, or the range of the voice in calling); and 1 krosha (or goruta ~ as far as a cow’s lowing may be heard, or a bull’s roar) may represent either 1000 or 2000 danda (a rod or staff).

Sound radiates in all directions, so perhaps there is some confusion in regarding a krosha either as the radius of travel in one direction or as the full diameter of travel.Man is the traditional measure of all things, and 1 danda represents 1 paurusa (a man’s length) which equals 1 dhanvantara (bow-string) or dhanu (bow). 1 yojana measures either 4,000 or (more likely) 8,000 dhanus. Assuming that 1 paurusha is 6 ft long, then 1 yojana must represent a distance of about 14.6 km (or about 9 miles, as suggested by Monier-Williams).A full range of self-consistent units was anciently devised from the proportions of man’s own frame, although their exact conversion into modern units is unclear. The basic unit is an angula (digit or finger), and 1 danda was perhaps originally divided into 100 digits, although 108 is the traditional value, and Aryabhatta prefers. Assuming a 6 ft danda, Aryabhatta’s angula is exactly ¾ inch (or about 1.9 cm).It does appear that 1 angula has always measured around 1.8 to 1.9 cm, with 1 danda or dhanu ranging from 1.83 to 2.05 m, so that 1 yojana must extend somewhere between 14.6 and 16.4 km. nimesha means shutting the eye or winking, and as a measure of time it is a wink of the eye or a moment. Kautilya’s Arthashastra (c.320 BC) defines 1 nimesha as 1/360,000th of a day and night ~ i.e. 0.24 seconds.2,202 yojanas in half a nimesha. Given that 1 yojana is between 14.6 and 16.4 km, 2,202 yojanas must represent between 32,149 and 36,113 km. Half a nimesha is 0.12 seconds.

Sayana thus gives the speed of light as between 267,910 and 300,940 km/sec ~ the currently accepted value for the speed of light being 299,792 km/sec. Assuming that the true speed of light was actually known to Sayana, who presented “2,202 yojanas in half a nimesha” as a verity; and accepting Kautilya’s value for nimesha; then a perfect yojana would be exactly 16,337.4636 m and a perfect paurusha or danda exactly 2.0422 m in length. And (assuming 108 digits per danda) then 1 angula = 1.89 cm, 1 dhanurgraha = 7.56 cm, 1 dhanurmushti = 15.13 cm, 1 vitasti = 22.69 cm, and 1 hasta (cubit) = 51.05 cm. All discussion of Sayana’s comment has assumed that one yojana is about 14.6 km, and this is based on the western ideal of a 6 ft man. The ancient sacred Egyptian cubit measured 28 angulas or 52.92 cm; and the ancient sacred Babylonian cubit measured 51.03 cm ~ i.e. 27 angulas ~ and this cubit was well known in ancient India. There are 32,000 hasta or cubits in a yojana; and if the Sumerian sacred cubit is assumed, then one yojana is actually 16.33 km. Therefore, 2,202 yojanas measures 35,958 km, and the speed of light is properly calculated to be 299,648 km/sec ~ and western science did not match the precision of Sayana’s estimate until 1907. The ordinary cubit measures 24 angulas (digits) or 6 dhanurgrahas (palms) or about 45 cm. The old Egyptian royal cubit measured 28 digits (each 1.8710 cm) or 7 palms (each 13.0970 cm) ~ i.e. 52.3881 cm. A copper bar from Nippur (c. 2650 BC) perhaps defined a Sumerian cubit of about 51.85 cm. The Persian cubit measured about 50.01 cm. The Harappan cubit was between 51.562 cm and 52.324 cm in length. Thus, an ordinary man is about 1.8 m tall, and his travel is measured by stages of about 14.5 km. The divine Egyptian ruler measured 2.09552 m, and his journey was by stages of 16.7642 km. The copper man of Nippur would perhaps have stood 2.074 high, with leaps of 16.592 km.

The Persian paurusha was about 2.0004 m long, with stages or yojanas of 16.0032 km. The Indus standard was between 2.062 and 2.093 m, with yojanas from 16.50 to 16.74 km. Given the dictum of 2,202 yojanas in half a nimesha, an ordinary man would judge the speed of light to be 266,075 km/sec; and the pharaoh’s photon would travel at 307,623.07 km/sec, but neither the royal Egyptian cubit of 28 digits nor the mortal human cubit of 24 digits is appropriate for this formula, which traditionally relies on a measure of 108 (i.e. 4 x 27) digits. The Nippur standard would provide a speed of 304,463.2 km/sec; the Persian standard gives us 293,658.72 km/sec; and the Sarasvati standard gives a figure somewhere between 302,775 km/sec and 307,179 km/sec. Assuming a perfect yojana, the constant of 2,202 could actually be any number from 2,182 to 2,222, and the resultant speed of light would still be accurate to within 1 percent. Very simply, light travels about 2,200 yojanas in half a nimesha; so that light travels about 2,200 x 720,000 yojanas in a day. And given a yojana of about 16.5 km, this means that the speed of light was anciently calculated to be about 302,500 km/sec. The modern accepted value for the speed of light is exactly 299,792.457