Differential Equations used in Siddhantas

Motional strength is one the sixfold strengths, known as Cheshta Bala. This motional strength is computed by the formula

Motional Strength = 0.33 ( Sheegrocha or Perigee – geocentric longitude of the planet ). This motional strength is known as Cheshta Bala.

Differential Calculus is the science of rates of the change. If y is the longitude of the planet and t is time, then we have the differential equation ,dy/dt.

During direct motion, we find that dy/dt > 0 and during retrogression dy/dt < 0. During backward motion of the planet ( retrogression) y decreases with time and during direct motion y increases with time. When there are turning points known as Vikalas or stationary points, we have dy/dt = 0 ( where planets like Mars will appear to be stationary for an observer on Earth ). The quantity in bracket is the Sheegra Anomaly, the Anomaly of Conjuction, the angular distance of the planet from the Sun. This Anomaly or Cheshta Bala is maximum at the center of the Retrograde Loop. Cheshta Kendra is defined as the Arc of Retrogression and is the same as Sheegra Kendra, Kendra being an angle in Sanskrit. During Opposition, when the planet is 180 degrees from the Sun, Cheshta Bala is maximum and during Conjunction, when the planet is 0 degrees from the Sun, it is minimum The Motional Strength is given in units of 60s, Shashtiamsas. Direct motion ( Anuvakra ) 30
Stationary point ( Vikala ) 15

Very slow motion ( Mandatara ) 7.5

Slow motion ( Manda ) 15

Average speed ( Sama ) 30

Fast motion ( Chara ) 30

Very fast motion ( Sheegra Chara ) 45

Max orbital speed ( Vakra ) 60

(Centre of retrograde)

The Nine Oribtal Elements

Mean and true planetary longitudes in the Zodiac is computed by Nine Orbital Elements, in Indian Astronomy.

Mean longitude of Planet, Graha Madhyama , M

Daily Motion of the Mean Longitude, Madhyama Dina Gathi, Md

Aphelion, Mandoccha, Ap

Daily Motion of Aphelion, Mandoccha Dina Gathi, Apd

Ascending Node, Patha, N

Daily Motion of Ascending Node, Patha Dina Gathi, Nd

Heliocentric Distance, Manda Karna, radius vector, mndk

Maximum Latitude, L, Parama Vikshepa

Eccentricity, Chyuthi,e

In Western Astronomy, we have six orbital elements

Mean Anomaly, m

Argument of Perihelion, w

Eccentricity, e

Ascending Node, N

Inclination, i, inclinent of orbit

Semi Major Axis, a

With the Nine Orbital Elements, true geocentric longitude of the planet is computed, using multi step algorithms.

There is geometrical equivalence between both the Epicycle and the Eccentric Models.

The radius of the Epicycle, r = e, the distance of the Equant from the Observer.

The Nine Oribtal Elements

Mean and true planetary longitudes in the Zodiac is computed by Nine Orbital Elements, in Indian Astronomy.

Mean longitude of Planet, Graha Madhyama , M

Daily Motion of the Mean Longitude, Madhyama Dina Gathi, Md

Aphelion, Mandoccha, Ap

Daily Motion of Aphelion, Mandoccha Dina Gathi, Apd

Ascending Node, Patha, N

Daily Motion of Ascending Node, Patha Dina Gathi, Nd

Heliocentric Distance, Manda Karna, radius vector, mndk

Maximum Latitude, L, Parama Vikshepa

Eccentricity, Chyuthi,e

In Western Astronomy, we have six orbital elements

Mean Anomaly, m

Argument of Perihelion, w

Eccentricity, e

Ascending Node, N

Inclination, i, inclinent of orbit

Semi Major Axis, a

With the Nine Orbital Elements, true geocentric longitude of the planet is computed, using multi step algorithms.

There is geometrical equivalence between both the Epicycle and the Eccentric Models.

The radius of the Epicycle, r = e, the distance of the Equant from the Observer.

The Nine Oribtal Elements

Mean and true planetary longitudes in the Zodiac is computed by Nine Orbital Elements, in Indian Astronomy.

Mean longitude of Planet, Graha Madhyama , M

Daily Motion of the Mean Longitude, Madhyama Dina Gathi, Md

Aphelion, Mandoccha, Ap

Daily Motion of Aphelion, Mandoccha Dina Gathi, Apd

Ascending Node, Patha, N

Daily Motion of Ascending Node, Patha Dina Gathi, Nd

Heliocentric Distance, Manda Karna, radius vector, mndk

Maximum Latitude, L, Parama Vikshepa

Eccentricity, Chyuthi,e

In Western Astronomy, we have six orbital elements

Mean Anomaly, m

Argument of Perihelion, w

Eccentricity, e

Ascending Node, N

Inclination, i, inclinent of orbit

Semi Major Axis, a

With the Nine Orbital Elements, true geocentric longitude of the planet is computed, using multi step algorithms.

There is geometrical equivalence between both the Epicycle and the Eccentric Models.

The radius of the Epicycle, r = e, the distance of the Equant from the Observer.

Astronomical Units of Time Measurement

We find Yuga cylces mentioned not only in astronomical works, but also in mythological works in India.

Kali Yuga began on the midnight of 17th Feb 3102 BCE and the duration of this Kali Yuga is said to be 4.32 K solar years. Dwapara is 2*Kali Yuga years. Treta is 3*K Y and Krita Yuga is 4*K Y.

Krita Treta Dwaparascha Kalischaiva Chaturyugam

Divya Dwadasabhir varshai savadhanam niroopitham

Thus an Equinoctial Cycle, Mahayuga is equal to 4+3+2+1 = 10 KYs.

E C = 10 KYs.

A Greater Equinoctial Cycle ( Manvantara ) = 71 Equinoctial Cycles

There are cusps happening in between Manvantaras, each equal to a Krita Yuga in duration. A Krita is equal to 4 KYs or 2/5 of a Maha Yuga. Since there will 15 such cusps happening amongst the Fourteen Manvantaras, they are equal to 15*2/5 = 6 Mahayugas.

Hence 14*71+6 = 1000 Mahayugas = 4.32 Billion Years



Sahasra yuga paryantham

Aharyal brahmano vidu

Ratrim yugah sahasrantham

The Ahoratra vido janah ( The Holy Geetha ).

This is one Cosmological Cycle, called Brahma Kalpa.

Chaturyuga sahasram indra harina dinam uchyathe

From one second, it can be logarithmically shown, upto 10^22 seconds. This is what the above diagram shows. This diagram is by courtesy of Wikipedia.

From 10^0 it goes upto 10^22 seconds. One day of Brahma is 4.32 billion years and 100 years of Brahma therefore is 311.04 trillion years, which is shown logarithmically above.

One Asu is 4 seconds, one Vinadi is 24 seconds and one Nadi is 24 minutes. 60 such Nadis make up one day. This is the Sexagesimal division of a day into 60 Nadis ! In Astronomy, one degree is sixty minutes and one minute is sixty seconds. Hence sexagesimal division is justified ! 365.25 such days constitute a year and Hindu calculation goes upto 311.04 trillion years !

Astronomical Units of Time Measurement

We find Yuga cylces mentioned not only in astronomical works, but also in mythological works in India.

Kali Yuga began on the midnight of 17th Feb 3102 BCE and the duration of this Kali Yuga is said to be 4.32 K solar years. Dwapara is 2*Kali Yuga years. Treta is 3*K Y and Krita Yuga is 4*K Y.

Krita Treta Dwaparascha Kalischaiva Chaturyugam

Divya Dwadasabhir varshai savadhanam niroopitham

Thus an Equinoctial Cycle, Mahayuga is equal to 4+3+2+1 = 10 KYs.

E C = 10 KYs.

A Greater Equinoctial Cycle ( Manvantara ) = 71 Equinoctial Cycles

There are cusps happening in between Manvantaras, each equal to a Krita Yuga in duration. A Krita is equal to 4 KYs or 2/5 of a Maha Yuga. Since there will 15 such cusps happening amongst the Fourteen Manvantaras, they are equal to 15*2/5 = 6 Mahayugas.

Hence 14*71+6 = 1000 Mahayugas = 4.32 Billion Years



Sahasra yuga paryantham

Aharyal brahmano vidu

Ratrim yugah sahasrantham

The Ahoratra vido janah ( The Holy Geetha ).

This is one Cosmological Cycle, called Brahma Kalpa.

Chaturyuga sahasram indra harina dinam uchyathe

From one second, it can be logarithmically shown, upto 10^22 seconds. This is what the above diagram shows. This diagram is by courtesy of Wikipedia.

From 10^0 it goes upto 10^22 seconds. One day of Brahma is 4.32 billion years and 100 years of Brahma therefore is 311.04 trillion years, which is shown logarithmically above.

One Asu is 4 seconds, one Vinadi is 24 seconds and one Nadi is 24 minutes. 60 such Nadis make up one day. This is the Sexagesimal division of a day into 60 Nadis ! In Astronomy, one degree is sixty minutes and one minute is sixty seconds. Hence sexagesimal division is justified ! 365.25 such days constitute a year and Hindu calculation goes upto 311.04 trillion years !

Astronomical Units of Time Measurement

We find Yuga cylces mentioned not only in astronomical works, but also in mythological works in India.

Kali Yuga began on the midnight of 17th Feb 3102 BCE and the duration of this Kali Yuga is said to be 4.32 K solar years. Dwapara is 2*Kali Yuga years. Treta is 3*K Y and Krita Yuga is 4*K Y.

Krita Treta Dwaparascha Kalischaiva Chaturyugam

Divya Dwadasabhir varshai savadhanam niroopitham

Thus an Equinoctial Cycle, Mahayuga is equal to 4+3+2+1 = 10 KYs.

E C = 10 KYs.

A Greater Equinoctial Cycle ( Manvantara ) = 71 Equinoctial Cycles

There are cusps happening in between Manvantaras, each equal to a Krita Yuga in duration. A Krita is equal to 4 KYs or 2/5 of a Maha Yuga. Since there will 15 such cusps happening amongst the Fourteen Manvantaras, they are equal to 15*2/5 = 6 Mahayugas.

Hence 14*71+6 = 1000 Mahayugas = 4.32 Billion Years



Sahasra yuga paryantham

Aharyal brahmano vidu

Ratrim yugah sahasrantham

The Ahoratra vido janah ( The Holy Geetha ).

This is one Cosmological Cycle, called Brahma Kalpa.

Chaturyuga sahasram indra harina dinam uchyathe

From one second, it can be logarithmically shown, upto 10^22 seconds. This is what the above diagram shows. This diagram is by courtesy of Wikipedia.

From 10^0 it goes upto 10^22 seconds. One day of Brahma is 4.32 billion years and 100 years of Brahma therefore is 311.04 trillion years, which is shown logarithmically above.

One Asu is 4 seconds, one Vinadi is 24 seconds and one Nadi is 24 minutes. 60 such Nadis make up one day. This is the Sexagesimal division of a day into 60 Nadis ! In Astronomy, one degree is sixty minutes and one minute is sixty seconds. Hence sexagesimal division is justified ! 365.25 such days constitute a year and Hindu calculation goes upto 311.04 trillion years !

The Geometric Model of Paramesvara

The Indian astronomers were interested in the computation of eclipses, of geocentric longitudes, the risings and settings of planets,which had relevance to the day to day activities of people.

Did not Emerson say?

“Astronomy is excellent, it should come down and give life its full value, and not rest amidst globes and spheres “.

They were not bothered about proposing Models of the Universe and gaining publicity. But then they did discuss the geometrical model, the rationale of their computations.

The above diagram explains the Geometric Model of Parameswara, another Kerala astronomer. Paramesvara and Nilakanta modified the Aryabhatan Model.

By Sheegroccha, he meant the longitude of the Sun.” Sheegrocham Sarvesham Ravir bhavathi “, he says is his book Bhatadeepika . For the interior planets, the longitude of the Sheegra correction is to be deducted from the Sun’s longitude, Ravi Sphuta to get the Anomaly of Conjunction.

The Manda Prathimandala is the mean angular motion of the Planet, from which the trignometric corrections are given to get the true, geocentric longitude.

The Geometric Model of Paramesvara

The Indian astronomers were interested in the computation of eclipses, of geocentric longitudes, the risings and settings of planets,which had relevance to the day to day activities of people.

Did not Emerson say?

“Astronomy is excellent, it should come down and give life its full value, and not rest amidst globes and spheres “.

They were not bothered about proposing Models of the Universe and gaining publicity. But then they did discuss the geometrical model, the rationale of their computations.

The above diagram explains the Geometric Model of Parameswara, another Kerala astronomer. Paramesvara and Nilakanta modified the Aryabhatan Model.

By Sheegroccha, he meant the longitude of the Sun.” Sheegrocham Sarvesham Ravir bhavathi “, he says is his book Bhatadeepika . For the interior planets, the longitude of the Sheegra correction is to be deducted from the Sun’s longitude, Ravi Sphuta to get the Anomaly of Conjunction.

The Manda Prathimandala is the mean angular motion of the Planet, from which the trignometric corrections are given to get the true, geocentric longitude.

The Geometric Model of Paramesvara

The Indian astronomers were interested in the computation of eclipses, of geocentric longitudes, the risings and settings of planets,which had relevance to the day to day activities of people.

Did not Emerson say?

“Astronomy is excellent, it should come down and give life its full value, and not rest amidst globes and spheres “.

They were not bothered about proposing Models of the Universe and gaining publicity. But then they did discuss the geometrical model, the rationale of their computations.

The above diagram explains the Geometric Model of Parameswara, another Kerala astronomer. Paramesvara and Nilakanta modified the Aryabhatan Model.

By Sheegroccha, he meant the longitude of the Sun.” Sheegrocham Sarvesham Ravir bhavathi “, he says is his book Bhatadeepika . For the interior planets, the longitude of the Sheegra correction is to be deducted from the Sun’s longitude, Ravi Sphuta to get the Anomaly of Conjunction.

The Manda Prathimandala is the mean angular motion of the Planet, from which the trignometric corrections are given to get the true, geocentric longitude.