Newton’s Laws of Motion.
- First law: When viewed in an inertial reference frame, an object either remains at rest or continues to move at a constant velocity, unless acted upon by an external force.
- Second law: F = ma. The vector sum of the forces F on an object is equal to the mass m of that object multiplied by the accelerationvector a of the object.
- Third law: When one body exerts a force on a second body, the second body simultaneously exerts a force equal in magnitude and opposite in direction on the first body.
|I. Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it.|
|II. The relationship between an object’s mass m, its acceleration a, and the applied force F is F = ma. Acceleration and force are vectors (as indicated by their symbols being displayed in slant bold font); in this law the direction of the force vector is the same as the direction of the acceleration vector.|
|III. For every action there is an equal and opposite reaction.|
Rig Vedic Verses on Laws of Motion.
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.”
The first one is Rigveda 10.149.1.This is one of the several Mantras in Vedas that assert that planets move around sun. It says:
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.
The second one Rigveda 8.12.28 details this motion of planet
“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
(The reference to sun comes from rest of the Mantras in this Sukta before and after this mantra)
The mantra clearly states that:
1. Motion of planets around the sun is not circular, even though sun is the central force causing planets to move (Refer previous mantra 10.149.1)
2. The motion of planets is such that Velocity of planets is in inverse relation with the distance between planet and sun.
It can be easily shown with the help of Newton’s Second Law that, for a planet revolving around sun in an elliptical orbit, having distance ‘r’ with sun and angle ‘θ’ made between length ‘r’ and any fixed axis, at any instant, following holds true
From the above, it can be easily shown that derivative of the product of square of distance between sun and planet and rate of change of angle θ, with respect to time, is zero. And thus following relation is obtained (with h as a constant)
Interestingly, the above relation is nothing but the conservation of angular momentum, observed in cases involving Central Forces! If you replace angular velocity with linear velocity, it leads exactly to the same principle that the Vedic mantra 8.12.28 asserts – that velocity of planets is inversely related to distance from sun!
Refer the following link for more verses.