Are there any references to Gravity or any fundamental forces in Hindu Scriptures viz. Vedas, Upanishands and Puranas or any Scientific Vedic Scriptures?
Due to the dominance of Vedanta school in present time, Sanatana Dharma (Hinduism) is often seen only in the light of Vedanta. If we go with respect to doctrines, Vedanta is only a small part of philosophies of Sanatana Dharma.
Sanatana Dharma is mainly represented by six philosophies like Vedanta, Mimamsa, Nyaya etc.. Among the six school of philosophy, Vaishesika is one of them. Vaisheshika philosophy was founded by Maharsi Kanada.
Just as Vedanta is represented by Brahma Sutra in a concise manner, Vaishesika philosophy is concised by Vaishesika Sutra. Vaishesika Sutra are very old texts. Even the western indologists date it to older than 500 BCE. And Vaisheshika Sutra clearly discuss about Gravity in the Sutras themselves.
Vaishesika Sutra discuss about role of Gravity in mainly three events:
1) Why does an object held fall when you let go?
To describe this first of all Sutra 5.1.6 states:
आत्मकर्म हस्तसंयोगाश्च ।
Action of body and it's members is also from conjunction with the hand.
As the above Sutra describes that it is due to conjunction with hand object remains. Then the next Sutra describes that in the absence of conjuction falling results due to Gravity.
संयोगभावे गुरुत्वात्पतनम (V.S. 5.1.7)
In the absence of conjunction falling results from Gravity.
Thus it clearly recognizes objects fall downward due to Gravity.
2) Why does an object thrown in air fall after sometime?
Then Vaishesika Sutra discuss role of Gravity in falling of moving objects. It gives through the analogy of arrow. First it gives mechanism of arrow projection in Sutra 5.1.17
नोदनाद्यभिषोः कर्म तत्कर्मकारिताच्च संस्कारादुत्तरं तथोत्तरमुत्तरं च ।।
The first action of arrow is from impulse; the next is resultant energy produced by the first action, and similarly the next next.
Then it explains why it falls in next Sutra.
संस्काराभावे गुरुत्वात्पतनम (V.S. 5.1.18)
In the absence of resultant/propulsive energy generated by action, falling results from Gravity.
3) Why does water fall (and rise) ?
Then the Sutras discuss cause of falling of water from sky.
अपां संयोगाभावे गुरुत्वात्पतनम (V.S. 5.2.3)
The falling of water in absence of conjunction is due to Gravity.
Then it discusses flow of water.
द्रवथ्वास्यन्दनम् (V.S. 5.2.4)
Flowing results from fludity.
Then it discusses why water rises.
नाड्यो वायुसंयोगादारोहणम् ।(V.S. 5.2.5)
The Suns rays (cause) the ascent of water through conjunction with air.
Thus from above Sutras, we can acknowledge that Vaisheshika Sutra clearly discuss Gravity. It uses the word "Gurutwa" which is also used in present time to represent Gravity. Gurutwa means force which arises due to mass.
However Vedanta School in Vedanta Sutra/ Brahma Sutra doesn't discuss about Gravity. In my view it is because it doesn't think Gravity is a worthy thing to be discussed as Vedanta Sutra are related to realization of Brahman and topics like Gravity aren't worthy to be discussed in Brahma Sutras.
One can read Vaisheshika Sutras with translation here.
MOTION OF EARTH
Rig Veda 10.22.14
“This earth is devoid of hands and legs, yet it moves ahead. All the objects over the earth also move with it. It moves around the sun.
In this mantra,
Kshaa = Earth (refer Nigantu 1.1) Ahastaa = without hands Apadee = without legs Vardhat = moves ahead Shushnam Pari = Around the sun Pradakshinit = revolves
Rig Veda 10.149.1
“The sun has tied Earth and other planets through attraction and moves them around itself as if a trainer moves newly trained horses around itself holding their reins.”
In this mantra,
Savita = Sun Yantraih = through reins Prithiveem = Earth Aramnaat = Ties Dyaam Andahat = Other planets in sky as well Atoorte = Unbreakable Baddham = Holds Ashwam Iv Adhukshat = Like horses
Rig Veda 8.12.28
“All planets remain stable because as they come closer to sun due to attraction, their speed of coming closer increases proportionately.”
In this Mantra,
Yada Te = When they Haryataa = Come closer through attraction Hari = Closeness Vaavridhate = Increases proportionately Divedive = continuously Vishwa Bhuvani = planets of the world Aditte = eventually Yemire = remain stable
Rig Veda 1.6.5, Rig Veda 8.12.30
“O God, You have created this Sun. You possess infinite power. You are upholding the sun and other spheres and render them steadfast by your power of attraction.
Yajur Veda 33.43
“The sun moves in its own orbit in space taking along with itself the mortal bodies like earth through force of attraction.”
Rig Veda 1.35.9
“The sun moves in its own orbit but holding earth and other heavenly bodies in a manner that they do not collide with each other through force of attraction.
Rig Veda 1.164.13
“Sun moves in its orbit which itself is moving. Earth and other bodies move around sun due to force of attraction, because sun is heavier than them.
Atharva Veda 4.11.1
“The sun has held the earth and other planets”
LIGHT OF MOON
Rig Veda 1.84.15
“The moving Moon always receives a ray of light from sun”
Rig Veda 10.85.9
“Moon decided to marry. Day and Night attended its wedding. And sun gifted his daughter “Sun ray” to Moon.”
Rig Veda 5.40.5
“O Sun! When you are blocked by the one whom you gifted your own light (moon), then earth gets scared by sudden darkness.”
RigVeda Hymn 1.35.9
हिरण्यपाणिः सविता विचर्षणिर उभे दयावाप्र्थिवी अन्तर ईयते | अपामीवाम बाधते वेति सूर्यम अभि कर्ष्णेन रजसा दयाम रणोति ||
हिरण्यपाणिः ...the golden-handed; सविता...sun; विचर्षणिर...very active or busy; उभे...fills; ईयते...so large; अन्तर...distance; दयावाप्र्थिवी... heaven and earth सूर्यम...sun; बाधते...drive away; अपामीवाम...disease; वेति...sets in motion; रणोति अभि...penetrates through; कर्ष्णेन रजसा...removes dark; दयाम... via compassion
The golden-handed Sun, the active, fills (with his rays) the large distance between the earth and heaven. He (the sun) drives away sickness, sets things in motion, penetrates through and removes darkness via his compassion.
There is definitely a hint to gravity here.
Praśnopaniṣad 3.8 and Śaṅkarācārya's commentary make a reference to gravity.
आदित्यो ह वै बाह्यः प्राण उदयत्येष ह्येनं चाक्शुषं प्राणमनुगृह्णानः ।
पृथिव्यां या देवता सैषा पुरुषस्यअपानमवष्टभ्यान्तरा यदाकाशः स समानो वायुर्व्यानः ॥ ८ ॥
ādityo ha vai bāhyaḥ prāṇa udayatyeṣa hyenaṃ cākśuṣaṃ prāṇamanugṛhṇānaḥ |
pṛthivyāṃ yā devatā saiṣā puruṣasyaapānamavaṣṭabhyāntarā yadākāśaḥ sa samāno vāyurvyānaḥ || 8 ||
8. The sun, indeed, is the external prâna. He rises favouring the prâna in the eye. So the goddess of the earth attracts the apâna downwards. The âkâsa between is samâna. The wind is vyâna.
Com. — The sun is the well-known outward Prâna among the Dêvâs. He rises and by his light favours this prâna, lodged in the eye of the body, i.e., helps it with luminosity in the perception of forms. Similarly the well-known goddess presiding over earth, attracts or controls the activity of the apâna in the purusha and favours its action by pulling downwards; for, otherwise, this body, owing to its weight, may fall down, or being unimpeded, may fly up. The air in the âkâsa, in the middle, i.e., between the earth and heaven (by the word âkâsa, the wind in it is denoted, as those in a cot are denoted by the word cot) is samâna, i.e., favours samâna, samâna resembling it, in the fact of being enclosed within the âkâsa in the middle. The external wind, vâyu, generally because it resembles vyâna in pervading, favours vyâna. This is the drift.
Yes, it is mentioned.
1)Why tides occurse?
Vishnu puran 2:4:89
“अन्यूनानतिरीक्ताश्च वर्धन्यापो हसंती च उदयास्तमनेष्विन्दो: पक्षयो: शुक्लकृष्णयो:” It holds Moon responsible for water’s ‘up & down (tide)’.
According to modern science, moon attracts water through it's gravity it means Hindus knew about gravity.
2)Why objects fall?
संयोगभावे गुरुत्वात्पतनम Every objects fall due to gravity in abscense of conjunction.
3)Gravity of sun
Brahmanda Purana 18.104.22.168-72a https://i.stack.imgur.com/nOA3j.png
Rigveda 1:35:6 (https://i.stack.imgur.com/KgUM2.png)!