Grateful to you, dear Bharat! Light and its speed.

 

Modern science today tells us that light travels at 186,282 miles/sec 299,792, km/sec. That is, if I ride the vehicle of light, I cover 186,282 miles in one sec. If I start my journey from the sun, then riding the vehicle of light, I reach the earth in about eight minutes.

 

[Source]

 

The key to estimating speed of light is to really know about the light that emanates from the sun . The ancient rishis of Bharat had this knowledge much before, much much before,  modern scientists even began speculating, estimating and then calculating  it.

 

Galileo, in 16th/17th century attempted a primitive experiment to measure the speed of light and failed. In 17th century, Danish astronomer Ole Romer, estimated the speed of light at about 2/3 of our current value by observing the eclipses of IO, one of Jupiter’s moons. Newton then refined the number a bit. Huygens built on Romer’s work and came up with a value for speed of light that is about 75 % of the value we have today. In 20th century, these estimates were further refined by Foucalt and Michelson to a value pretty close to the value we know today.

[Worshipping Light]

 

But in Bharath, Speed of Light was determined accurately in Rig Veda thousands of years ago. It was further elaborated by Sayanacharya in 14th century CE.

 

Rig Veda says,

 

“O Surya! your effulgence is swift and energetic, and  illumines all the radiant realms beautiful and charming”

 

Sayanacharya, in early 14th century CE, commenting on this verse of Rg Veda,said this effulgence of the sun travels 2202 yojanas in half a nimisha. In today’s language this is about 189,547 miles per second.

_____________

 

The fourth verse of the Rigvedic hymn 1:50 (50th hymn in book 1 of rigveda) is as follows:

तरणिर्विश्वदर्शतो ज्योतिष्क्र्दसि सूर्य |विश्वमा भासिरोचनम् |

taraNir vishvadarshato jyotishkrdasi surya |vishvamaa bhaasirochanam ||

“O Surya! your effulgence is swift and energetic, and  illumines all the radiant realms beautiful and charming”

 

तरणिः   taranih –  quick, ray of light

विश्वदर्शत: visvadarsatah – beautiful, of conspicuous beauty

ज्योति: jyotih – effulgence

क्रदसि  kradasi  – doing

सूर्य  suryah– sun

विश्वमा visvamaa – the universe

भासि bhaasi – illumine

रोचनम् rochanam – beautiful and bright

Sayanacharya was born in 1270 CE and lived in the area of today’s Hampi. He was a minister in the court of Bukka of the great Vijayanagar Empire. He was also the brother of Jagadguru Vidyaranya Swamigal, patron of the Vijayanagara empire and the 12th Jagadguru of the Sringeri Sharada Peetam. Sayanacharya was a scholar extraordinaire. He has left behind more than hundred works including commentaries on the vedas.

 Commenting in the above Rg Veda mantra, Sayanacharya has said:

तथा च स्मर्यते योजनानां सहस्रे द्वे द्वे शते द्वे च योजने| एकेन निमिषार्धेन क्रमामन्||

tatha ca smaryate yojananam. sahasre dve dve sate dve ca yojane | ekena nimishardhena kramaman ||  

Remember this. The light of the sun traverses 2202 yojanas in one nimishardha. 

 

तथा च स्मर्यते tatha ca smaryate  – it is remembered thus

योजनानां yojannam – of the Supreme Spirit of the Universe (Light of the sun)

सहस्रे द्वे द्वे शते द्वे च योजने, sahasre dve dve sate dve ca yojane  – 2202 yojanas

एकेन निमिषार्धेन, ekena nimishardhena  –  in one nimishardha

क्रमामन्, kramaman – traverses

Nimisha is a measure of time, about 0,2112 seconds or the “wink of an eye”. Nimishardha is half a nimisha or 0.1056 seconds.

Yojana is a measure of distance. One yojana s about 9.09 miles.

Speed of light in modern units based on the value given as 2202 yojanas in 1/2 nimesa

= 2202 x 9.09 miles per 0.1056 seconds

= 20016.18 miles per 0.1056 seconds

= 189547 miles per second 

As per modern science, speed of light is 186000 miles per second  (approximately)

___________

What is a nimisha? 

The Moksha dharma parva of Shanti Parva in Mahabharata describes Nimisha as follows:

15 Nimisha = 1 Kastha
30 Kashta = 1 Kala
30.3 Kala = 1 Muhurta
30 Muhurtas = 1 Diva-Ratri (Day-Night)
We know Day-Night is 24 hours
So we get 24 hours = 30 x 30.3 x 30 x 15 nimisha
in other words 409050 nimisha
We know 1 hour = 60 x 60 = 3600 seconds
So 24 hours = 24 x 3600 seconds = 409050 nimisha
409050 nimesa = 86,400 seconds
1 nimesa = 0.2112 seconds (This is a recursive decimal! Wink of an eye=.2112 seconds!)
1/2 nimesa = 0.1056 seconds

What is a yojana?

Yojana is defined in Chapter 6 of Book 1 of the ancient vedic text “Vishnu Purana” as follows

10 ParamAnus = 1 Parasúkshma
10 Parasúkshmas = 1 Trasarenu
10 Trasarenus = 1 Mahírajas (particle of dust)
10 Mahírajas= 1 Bálágra (hair’s point)
10 Bálágra = 1 Likhsha
10 Likhsha= 1 Yuka
10 Yukas = 1 Yavodara (heart of barley)
10 Yavodaras = 1 Yava (barley grain of middle size)
10 Yava = 1 Angula (1.89 cm or approx 3/4 inch)
6 fingers = 1 Pada (the breadth of it)
2 Padas = 1 Vitasti (span)
2 Vitasti = 1 Hasta (cubit)
4 Hastas = a Dhanu, a Danda, or pauruSa (a man’s height), or 2 Nárikás = 6 feet
2000 Dhanus = 1 Gavyuti (distance to which a cow’s call or lowing can be heard) = 12000 feet
4 Gavyutis = 1 Yojana = 9.09 miles

 

Acknowledgements:

1. https://interestingengineering.com/a-brief-history-of-the-speed-of-light
2. https://www.booksfact.com/vedas/rig-veda/speed-of-light-calculated-in-vedas-of-ancient-india.html
3. https://www.speakingtree.in/blog/the-speed-of-light-by-acharya-sayana