Thursday, 15 December 2022

COP 15 Montreal…

COP15 Montreal: Breakdown in talks on resource mobilisation; delegates walk out

Delegates from developing countries, including like-minded megadiverse ones, walked out of negotiations December 14, 2022, due to difference of opinion on a number of issues regarding resource mobilisation at the 15th Conference of Parties (COP15) to the UN Convention on Biological Diversity.

The walk out was precipitated by a discussion on the creation of a new fund on biodiversity.

Brazil spoke in a press statement for the coalition of like-minded developing countries. Biodiversity-rich countries will bear a higher burden than others in implementing an ambitious Global Biodiversity Framework (GBF). Hence, its adoption must be accompanied by approval of a commensurately robust package on resource mobilisation.

“In line with the principle of equity, it should ensure the provision of predictable, measurable, new, additional, and adequate financial resources from developed countries to developing ones. It should also ensure accessibility and proper monitoring of the financial commitments and pledges,” the statement said.

The like-minded countries indicated that a fund similar to the one established on loss and damage at COP27 in Sharm el-Sheikh should be set at COP15. They also said existing multilateral sources are not up to the task of meeting the requirements of the GBF.

The group has proposed that developed countries commit to mobilise and jointly provide financial grants of at least $100 billion annually or one-per cent of global GDP until 2030, an amount to be revised for the period 2030–2050.

The COP15 president and the Secretariat have orgnaised a meeting with the heads of delegation to resolve the impasse.

Target 19 of the Post-2020 Global Biodiversity Framework deals with the issue of resource mobilisation. A Global Biodiversity Fund is one of the proposed solutions to ensure that sufficient funds are available for meeting the three objectives of the Convention on Biological Diversity.

While there are multiple figures on the funds required for meeting the CBD objectives, the draft of the Framework shared on December 5 by the CBD indicates that at least $200 billion dollars are needed per year.

During the Fourth Open-ended Working Group meeting held in Nairobi, Kenya in June, African countries had proposed that one per cent of the retail price of all commercial income resulting from the utilisation of genetic resources, from traditional knowledge associated with genetic resources, or from DSIs should be put in a multilateral fund. They had indicated that failure of consensus on this issue would delay the adoption of the Framework.

The issue of resource mobilisation has been considered important enough for the secretariat to organise a Finance Day at the UN Biodiversity Conference. The Finance day provides an opportunity to the financial community to engage in discussion on biodiversity and multiple commitments are expected from governments, industry and funding agencies.

This impasse comes just a few days before the Post 2020 Global Biodiversity Framework is expected to be finalised and adopted on December 19. The COP15 High Level Session with Ministers, vice-Ministers, Ambassadors, and other Heads of Delegation of Parties to the UN Convention on Biological Diversity will be getting together from December 15-17 to finalise the text.

Meanwhile, Basile van Havre and Francis Ogwal, co-chairs for the CBD's Open-Ended Working Group for a Post-2020 Global Biodiversity Framework informed at a press meeting that work on the Framework is moving ahead steadily and it is likely to be adopted by the end of the meeting. Some of the text is clean now with the removal of square brackets.

Happy Morning…

Wednesday, 14 December 2022

Continental Drift Theory

Continental Drift Theory was put forward by the German scientist Alfred Wegner in 1915.

According to the Continental Drift Theory, part of the crust are capable of horizontal movement round the globe causing the continents to slowly change their positions in relation to one another.

The fact that South America is a mirror image of Africa is presented as a proof of the continental drift theory (see video below for an animation showing the migration of both of these continents).

For hundreds of millions of years, all the land of Earth was joined together in one large mass or super continent. Scientists call it Pangaea (meaning “all lands” in Greek). Then about 200 million years ago the land began to drift apart. It broke into two pieces, and scientists have called the continent in the north Laurasia and the continent in the south Gondwanaland (named by Eduard Suess, an Austrian geologist).The two large continents continued to break apart into the smaller continents that exist today. Scientists call this movement ‘continental drift’.

According to Wegener, the drift was in two directions:

Towards the equator due to the interaction of forces of gravity, pole-fleeing force (due to centrifugal force caused by earth’s rotation) and buoyancy (ship floats in water due to buoyant force offered by water)
Westwards due to tidal currents because of the earth’s motion (earth rotates from west to east, so tidal currents act from east to west, according to Wegener).

Wegener suggested that tidal force (gravitational pull of the moon and to a lesser extent, the sun) also played a major role.
The polar-fleeing force relates to the rotation of the earth. Earth is not a perfect sphere; it has a bulge at the equator. This bulge is due to the rotation of the earth (greater centrifugal force at the equator).
Centrifugal force increases as we move from poles towards the equator. This increase in centrifugal force has led to pole fleeing, according to Wegener.
Tidal force is due to the attraction of the moon and the sun that develops tides in oceanic waters (tides explained in detail in oceanography).
According to Wegener, these forces would become effective when applied over many million years, and the drift is continuing.

The evidences in support of the continental drift theory:

Jigsaw Fit:

The similarity in outline of the coastlines of eastern South America and West Africa had been noted for some time. The best fit is obtained if the coastlines are matched at a depth of 1,000 meters below current sea level

Geological Fit:

When the geology of eastern South America and West Africa was mapped it revealed that ancient rock outcrops (cratons) over 2,000 million years old were continuous from one continent to the other.

Tectonic Fit:

- Fragments of an old fold mountain belt between 450 and 400 million years ago are found on widely separated continents today.
- Pieces of the Caledonian fold mountain belt are found in Greenland, Canada, Ireland, England, Scotland and Scandinavia. When these land masses are re-assembled the mountain, belt forms a continuous linear feature.

Glacial Deposits:

- Today, glacial deposits formed during the Permo-Carboniferous glaciation (about 300 million years ago) are found in Antarctica, Africa, South America, India and Australia.
- If the continents haven’t moved, then this would suggest an ice sheet extended from the South Pole to the equator at this time – which is unlikely as the UK at this time was also close to the equator and has extensive coal and limestone deposits.
- If the continents of the southern hemisphere are re-assembled near the South Pole, then the Permo-Carboniferous ice sheet assumes a much more reasonable size

Fossil Evidence:

- There are many examples of fossils found on separate continents and nowhere else, suggesting the continents were once joined. If Continental Drift had not occurred, the alternative explanations would be:
- The species evolved independently on separate continents – contradicting Darwin’s theory of evolution.
- They swam to the other continent/s in breeding pairs to establish a second population.

Criticism faced by Continental Drift Theory:

Wegener failed to explain why the drift began only in Mesozoic era and not before.
The theory doesn’t consider oceans.
Proofs heavily depend on assumptions that are generalist.
Forces like buoyancy, tidal currents and gravity are too weak to be able to move continents.
Modern theories (Plate Tectonics) accept the existence of Pangaea and related landmasses but give a very different explanation to the causes of drift

Good morning….

Origin of Earth

we will read a total of 8 theories of the origin of the universe.

Gaseous hypothesis of Kant
Nebular hypothesis of Laplace
Planetesimal hypothesis of Chamberlin
Jean and Jeffery’s tidal theory
Russel’s binary Star Hypothesis
Hoyle’s supernova hypothesis
Schmidt’s interstellar hypothesis
Big bang theory

1. Gaseous hypothesis of Kant

Immanuel Kant, the German philosopher, presented his treatise entitled ‘The General Natural History and Theory of the Heaven or the Essay on the Working and Mechanical Origin of the Entire Universe on the Basis of Newtonian Laws’ in 1755.
Kant claimed that his ‘gaseous hypothesis’ of the origin of the earth was based on the sound principles of Newton’s laws of gravitation and rotatory motion.
In the beginning his hypothesis acclaimed world-wide appreciation but later on it was disproved as it was based on erroneous concepts and wrong application of Newtonian laws of gravitation.
Inspite of severe criticism the hypothesis was considered a great step forward in the field of cosmogony and ‘he almost reverberated the mid-18th century with his words…Give me matter and I will build a world out of it.’
Kant postulated his gaseous hypothesis of the origin of the earth on the basis of a few assumptions. He assumed that supernaturally created primordial hard matter was scattered in the universe.
In fact, according to Kant there was a primeval, slowly rotating cloud of gas (now called a nebula) and matter comprised of very cold, solid and motionless particles.
- Nebula – It is a primordial (primitive) amorphous (without shape) mass of cloud of gas and dust.
- In terms of modern scientific language it can be said (but not described by Kant) that the temperature of primordial matter was near about -273 °C or absolute zero or 0 K. This was the reason that cold matter was initially motionless (according to the molecular theory of matter).
He further assumed that the particles began to collide against each other under their mutual gravitational attractions. This mutual attraction and collision between the particles generated random motion in the primordial matter. Collision of the particles also generated friction which generated heat, with the result the temperature of the primordial matter started rising.
He further argued that the random motion of the particles also generated rotatory motion in the primordial matter. Thus, the original cold and motionless cloud of matter became in due course a vast hot nebula and started spinning (rotating) around its axis.
According to Kant with the increase in temperature, the random motion as well as the rate of collision among the particles also increased. This gave extra impetus of the rate of rotatory motion (spinning) of the primordial matter. The rise in temperature also changed the state of primordial matter from solid to gaseous particles. Thus, the initial primordial matter gradually changed in hot rotating nebula. With continuous rise in temperature and rate of rotatory motion the nebula started expanding in size.
According to Immanuel Kant as the heat increased, the size of nebula increased and as the size of nebula increased, the angular velocity or rotatory speed further increased.Due to continuous increase in the size of nebula the rotatory speed became so fast that the centrifugal force (away from the centre) exceeded the attractional or centripetal force (directed towards the centre).
The nebula started spinning so rapidly that an irregular ring was separated from the middle part of the nebula and was ultimately thrown off due to centrifugal force. By the repetition of the same process a system of concentric rings (nine) were separated from the nebula. The residual central mass of the nebula remained as the sun.
The irregularity of the rings caused the development of the cores (knots) for the formation of the corresponding planets. In other words, all the matters of each ring were aggregated at a point to form a core or a knot which ultimately grew as a planet in due course of time. Thus, it is apparent that according to Kant the earth was formed due to aggregation of all the matter of the ring which was separated from the nebula due to centrifugal force.
By the repetition of same process rings were separated from the newly formed planets and the materials of each ring were condensed to form satellites of the concerned planets. Thus, the whole solar system comprised of the sun (residual part of the rotating nebula), nine planets and their satellites were formed.

Evaluation

Though Immanuel Kant based his gaseous hypothesis on scientific principles (Newton’s law of gravitation) to solve the problem of the origin of the solar system and the earth but his hypothesis has been rendered baseless because it is based on several erroneous facts of science. In fact, Kant’s hypothesis was declared dynamically unsound:

It was one of the basic assumptions of Kant’s hypothesis that there was primordial matter in the universe but he never explained the source of the origin of the primordial matter.
Kant did not explain the source of energy to cause random motion of the particles of the primordial matter which were cold and motionless in the initial stage.
- According to Newton’s first law of motion ‘a body remains at rest, or if in motion it remains in uniform motion with constant speed, unless or until an external force is applied on it.’ The particles of the primordial matter, as assumed by Kant, were at rest and no external force was applied on them, then what was the cause for the random motion among the particles of primordial matter?
The collision among the particles of the primordial matter can never generate rotatory motion in it. It is an erroneous statement of mechanism.
- It means that if anybody is rotating, the total amount of its angular momentum will always remain constant unless an external force is applied on the rotating body.
- This statement is erroneous as it is against the law of conservation of angular momentum.

Thus, the very foundation, on which Kant’s hypothesis was based, is proved unsound and wrong. However, the importance of Kant’s hypothesis lies in the fact that it was first scientific attempt for the explanation of the origin of the earth. In fact, Kant’s hypothesis paved the way for the postulation of nebular hypothesis by Laplace.

2. Nebular hypothesis of Laplace

Laplace, a French scholar, proposed the “Nebular Hypothesis of Laplace,” which is one of the earliest theories on the origin of the earth. Laplace attempted to revise Kant’s Gaseous Hypothesis.
In terms of the assumption of primordial matter, Laplace’s nebular hypothesis differs from Kant’s. Kant considered that primordial substance was composed of a cloud or nebula of cold static matter. Nebulae, according to Laplace, are made out of hot primordial matter. Pierre Simon de Laplace suggested the Nebular Hypothesis in 1796.

Assumptions

He assumed that there was a huge and hot gaseous nebula in the space.
From the very beginning huge and hot nebula was rotating on its axis.
The nebula was continuously cooling due to loss of heat from its outer surface through the process of radiation and thus it was continuously reduced in size due to contraction on cooling.

According to Laplace

Based on the above mentioned assumptions Laplace believed that the nebula was formed of gases rather than solids, and that everything, including the sun, stars, plants, and asteroids, was formed from the nebula cloud.
Initially, there was a nebula cloud composed of Helium, Hydrogen, and dust particles, with a size similar to that of the present-day solar system.
Since, Nebula was continuously reduced in size due to gradual loss of heat from the outer surface of the nebula through radiation.
Thus, Reduction in the size and volume of the nebula increased the circular velocity (rotatory motion) of the nebula.
Due to the increase in velocity, nebula started spinning at very fast speed and consequently the centrifugal force becomes so great that it exceeded the centripetal force.
Consequently, the Outer surface was condensed due to excessive cooling and so it could not rotate with the still cooling and contracting the central nucleus of the nebula.
And, Thus the outer ring was separated from the remaining part of the nebula.
And this separated ring started moving around the nebula.
Laplace further maintained that the original ring was divided into nine rings and each ring moved away from the outer ring.
Thus, nine planets were formed from the nine rings and the remaining central nucleus of the nebula become the Sun.

Evaluations

He did not describe the source of the origin of the nebula.
He did not explain that, why did only 9 rings come out from irregular ring detached from the nebula?
If the sun is the remaining nucleus of the nebula as claimed Laplace, it should have a small bulge around its middle part which would point out the probable separation of the irregular ring from the sun but there is no such bulge in the middle part of the sun.
According to the nebular hypothesis all satellites should revolve in the direction of father planets but few satellites of Saturn and Jupiter revolve in the opposite direction of their father planets.
The nebular hypothesis is unable to explain the peculiar distribution of present-day angular momentum in our solar system.

Outcome: The merit of the theory lies in the fact that it is the most acceptable explanation in explaining the layered structure of the earth’s interior.

3. The planetesimal hypothesis of Chamberlin (1905)

The conroversy of peculiar redistribution of angular momentum in our solar system from the original angular momentum of Laplace’s nebula shattered the very basis of mono-parental or monistic concepts of the origin of the earth (and the planets). That is why , the idea of biparental or dualistic concept of the origin of the earth started gaining currency and respect among the scientists of the 1st quarter of the 20th century. Planetesimal hypothesis propounded jointly by Chamberlin and Moulton belongs to the dualistic concepts of the origin of the earth.
Planetesimal hypothesis not only explains the origin of the earth but also throws light on the structure of the earth, the origin of its atmosphere and continents and ocean basins.
Unlike monistic concept (e.g. gaseous hypothesis of Immanuel Kant and nebular hypothesis of Laplace) the planetesimal hypothesis envisaged the origin of the solar system (and the earth) with the help of two heavenly bodies.
According to Chamberlin initially there were two heavenly bodies (stars) in the universe–
- Proto-Sun
- and its Companion Star or Intruding star
The behavior and properties of proto-sun were not like other stars, It was formed of very small particles which were cold and solid. Thus, the proto-sun, unlike Laplace’s nebula, was not hot and gaseous rather it was formed of solid particles and was cold and circular in shape. There was another star, termed as ‘intruding star’ or ‘companion star which was destined to pass very close the proto-sun.
When the intruding star came very close to the the Proto-Sun infinite number of small particles were detached from the outer surface of proto-sun due to massive gravitational pull exerted by the giant intruding star. This matter which is dust, gases, rock fragments eventually accrete forming planets & other celestial bodies that revolve around the proto sun.
Initially, the detached particles or planetesimals were just like dust particles. The planetesimals were not of uniform size rather a few planetesimals around the proto-sun were of fairly big size. These larger planetesimals became nuclei for the formation of future possible planets. Gradually, large planetesimals started attracting small planetesimals.
Thus, numerous small planetesimals were accreted (added) to the nuclei of large planetesimals and ultimately these large planetesimals grew in the form of planets due to continuous accretion of infinite number of planetsimals. With the passage of time, the remaining proto-sun changed into the present-day sun. The satellites of the planets were created due to the repetition of the same processes and mechanisms.

4. Jean and Jeffery’s tidal theory

This theory is somewhat similar to Chamberlin’s theory that an intruding star ejects matter from the proto sun. Chamberlin, in his theory, had assumed the proto sun to be initially as a cold body whereas the Tidal theory assumes the proto sun to be hot and incandescent.
According to Tidal theory, the matter ejected are not randomly thrown dust, gases, planetesimal.

The universe expanded from a very high density & high-temperature state.

There was a major cosmic explosion 13-15 bn yrs ago from which all the matter of the universe was thrown out which eventually accreted to form stars, solar system and celestial bodies.

Evidence in support:

Red Shift: As an object (light) moves away from us, its wavelength increases & shift to the Red end of the spectrum (Called Red Shift).
CBMR: Electromagnetic Radiation which was present shortly after the big bang, is now observed as background microwave radiation.

Tuesday, 13 December 2022

Good Morning…

Monday, 12 December 2022

CONVECTION CURRENT THEORY…

Convectional Current Theory talked about the possibilities of mantle convection currents. Radioactive elements in the mantle cause thermal variations, which generate these currents. In the 1930s, Arthur Holmes proposed this Theory.

According to Holmes, the entire mantle region contains a system of similar currents. This was an attempt to explain the question of force, which led to the rejection of the continental drift theory by contemporary scientists as Alfred Wegener was unable to explain the reason for the movements of plates in the western direction.

Conventional Current

Convection is a heat transfer process that involves the movement of fluids between various temperature zones.
A convection current is a process in which energy is transferred from one location to another. It is also known as convection heat transfer.
Convection currents cannot occur in solids.
Reason: The particles within the solids cannot easily flow, and most of the free movement is due to a difference in density generated by a large heat transfer between the plates.

Convectional Current Theory

In the 1930s, Arthur Holmes proposed the Convectional Current Theory. Convection Current Theory is the soul of Seafloor Spreading Theory.
According to this theory, the extreme heat generated by radioactive chemicals in the mantle (100-2900 km beneath the earth's surface) seeks a way to escape and causes convection currents to emerge in the mantle.
Under the solid lithosphere, the fluid asthenosphere circulates as convection currents.
Divergent convective currents pull crustal blocks away from each other in opposite directions, forming seas and oceans. East Africa's lakes system, the Mid-Atlantic Ridges, and so on are examples.
Convergent convective currents generate subsidence in the crustal zones, resulting in geosynclines and sea closure, resulting in the construction of island arcs, mountains, and other features.
Convection currents run through the mantle's molten rock, acting as a conveyor belt for the plates.
The total change in the lithospheric materials is constant since these currents are closed in nature.

Criticism of Convectional Current Theory

The entire process of convection currents is based on heat generated by radioactive materials in the substratum (now mantle), however numerous scientists have questioned whether the needed amount of heat generated by radioactive elements is available.
Convective currents may not be formed if heat is insufficient, and so the entire mechanism and working of the theory will be impossible. It's also worth noting that rising currents condense their heat into the crust.
This process also results in heat loss, which could cause currents to weaken.
Because of a lack of heat to generate these currents, the horizontal flow of thermal convection currents beneath the continental and oceanic crusts is likewise a dubious phenomenon.
If the convergent movement of convective currents cannot flow horizontally, the descending column will not exist, and the mountain will not develop.

Conclusion

It can be concluded that A. Holmes' theory of thermal convection currents, which he developed roughly 80 years ago, demonstrated its utility in the 1960s, when scientists were hunting for a force that might explain plate movement. Now, the process of mountain formation may be satisfactorily explained using convective currents, though not in the way that A. Holmes envisioned in 1928-29, but rather along the lines of plate tectonics.

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