Many Scholars tried to explain the Origin of Earth. ‘Sir James Jeans’ was also one of them. He propounded ‘Tidal Hypothesis’ in 1919. Tidal Hypothesis is the part of Dualistic Concept ( Involvement of two heavenly bodies ) of Earth Origin. To make it more acceptable and match the 20th Century Knowledge, Harold Jeffreys modified it in 1929.
James jeans postulated his hypothesis on the basis of 6 Assumptions.
1. The solar system was formed by 2 Stars – Our sun and another Intruding star.
2. The sun was big and bright gaseous mass of matter.
3. There was another star termed as ‘Intruding star ‘, which was much bigger then Our Sun.
4. Our sun was stationary and was rotating on its axis.
5. The Intruding star was moving along such a Path in such a way that it was destined to come nearer to the Sun.
6. The Tidal force of the Intruding star affected the Surface of our sun.
Now, James Jeans said that The Intruding Star was Very Big Compared to the Sun, that’s why it had more Gravitational Pull then the sun. When the Intruding star came to the nearest point to the sun its massive Gravitation force, pulled huge Cigar shaped Matter out of the sun.
Why Cigar shaped Element Came Out of Sun?
He Explained it like –
when the Intruding Star came in the distant range of the sun its Gravitational Force was low therefore small quantity came out first.
When it reached the nearest point it exerted the maximum gravitational pull and Pulled the most matter out of the sun.
When the Intruding star was moving away from the sun its gravitational pull was also decreasing therefore the pulling of matter also decreased.
This is how he explained the Cigar shaped Filament (James Called the pulled material as filament)
Next Step –
Gradually and Gradually the Intruding star was going away from the range of the sun. The filament was trying to go with the Intruding star but not able to succeed. The sun was also not able to pull it back . Ultimately it started revolving around the sun.
Later, the cigar shaped filament cooled and broke down into 9 pieces which later became the planets.
The planets cooled according to their size, small planets cooled down fast and attained the solid form, while giant planets took more time in cooling and ejected more material due to the gravitational pull from other planets.
That ejected material, later developed into the satellites.
Evidence in favor of the Hypothesis –
The Tidal Hypothesis was able to explain the origin of solar system as well as its shape size and structure.
1.Shape and order of planets – The filament was cigar-shaped, thicker in middle part and narrower in both ends.
As shown in the photos, Jupiter is the biggest planet which exist in the center and most wider part of that filament.
Size of the planets decreases on both side of the Jupiter. on the ends we have mercury and Pluto which were the smallest .
This point is considered very significant because when James Jeans gave this hypothesis, Pluto was not discovered.
2.Ordering and arrangement of Satellites – as explained above, Bigger planets cooled down slowly and ejected more material. The bigger the planet is more the number of satellites it have.
Also their arrangement is in same cigar shape, For example the bigger satellite is in center and smaller ones are placed in the ends.
This is also a strong point for the Tidal Hypothesis.
3. Number and size of satellites – Small planets cooled fast therefore, ejected less or no material, This is a reason why they have 1 or 2 or no satellite.
Where as Big planets cooled slowly and ejected more material so they have bigger and more number of satellites.
4. Rotation, Revolution and Inclination of the Planets’ Axis – Filament was revolving around the sun on the same orbit and the planets should do the same, and they are doing the same.
we can see that the Filament was inclined toward the Intruding star. and all our planets are inclined For example our earth is inclined 23.5 degrees.
Modifications by Harold Jeffreys- 1929
Jeffreys modified the ‘Tidal Hypothesis’ and named it ‘Collision Hypothesis’
He said there was 3 Stars – Sun, Companion Star and Intruding Star.
Companion star collided with the Intruding star and smashed it completely.
Its pieces get scattered into the space and some started revolving around the sun. The debris from the companion star later became the planets. and due to the impact of collision the intruding star was thrown away from the sun.
Jeffreys tried to remove the weakness from the tidal Hypothesis to withstand criticisms.
criticism to Tidal Hypothesis –
B. Levin said that such a close encounter between the stars is a remote possibility
James Jean did not explained from which point tidal eruption happened on sun. Is there any mark on sun?
If we look at the Distance of Planets according to tidal hypothesis, planets should we very close to the sun but in reality they are very far away from the sun.
If our sun is made up of lighter elements like hydrogen and helium, why our planets have heavier elements?
James Jean could not elaborate the process of cooling of the planets.
if satellites are made up of the material pulled by the gravitational force, then why note Mercury or Venus have satellite they had maximum gravitational pull of the sun.
So this was all about the Tidal Hypothesis, if you have any questions or want to suggest anything don’t forget to comment down.!! Find more at Physical Geography.
