Question 3

Q. Can the same data be supported by multiple theories? give some examples.

Posted By: Anveshna Srivastava
      

 

                                      Yes, same data may be supported by multiple theories at a given time. We can look at different theories as different bodies that can be more or less independent of each other. Just as phylogenetically-later organisms are dependent on the former organisms (because without the former the latter could not possibly have come into existence), similarly the generatively-latter theories are semantically dependent on former theories.

                                    It is reasonable enough to think that scientific theories are also independent bodies in the sense that each has its own domain of application. Theories do show structural differences though they are genetically dependent on former theories. This looks more true to the way scientists operate with theories. Old theories have all been stated to be dislodged by more general theories. However, the facts look quite different if we see the manner in which practicing scientists continue to employ those so called ‘dislodged’

theories even today (like Newtonian Physics).                             

                                   Einstein and few others of his genre might have dislodged Newtonian theory from their mind, but not the entire community of scientists. Scientists continue to work with Newtonian theory, Euclidian geometry, natural numbers, integers etc., whenever they find them relevant.                                                   Few examples could be given where different theories are employed to explain the same phenomena and these theories are equally plausible:

A) Theories on the Conception of human mind
                                     The two theories -Computational theory of mind & Cognitive Embodied philosophy are equally plausible when it comes to unentangling the conceptual processing of mind.
1. Computational theory of mind:

 

In philosophy, the computational theory of mind is the view that the human mind is best conceived as an information processing system and that thought is a form of computation. The theory was proposed in its modern form by Hilary Putnam in 1961 and developed by Jerry Fodor in the 60s and 70s.This view is common in modern cognitive psychology and is presumed by theorists of evolutionary psychology.

The computational theory of mind is a philosophical concept that the mind functions as a computer or symbol manipulator. The theory is that the mind computes input from the natural world to create outputs in the form of further mental or physical states. A computation is the process of taking input and following a step by step algorithm to get a specific output. The computational theory of mind claims that there are certain aspects of the mind that follow step by step processes to compute representations of the world, however this theory does not claim that computation is sufficient for thought.

2. Cognitive Embodied Philosophy:

Philosophers, cognitive scientists and artificial intelligence researchers who study embodied cognition and the embodied mind believe that the nature of the human mind is largely determined by the form of the human body. They argue that all aspects of cognition, such as ideas, thoughts, concepts and categories are shaped by aspects of the body. These aspects include the perceptual system, the intuitions that underlie the ability to move, activities and interactions with our environment and the naive understanding of the world that is built into the body and the brain.

The embodied mind thesis is opposed to other theories of cognition, such as cognitivism, computationalism and Cartesian dualism. The idea has roots in Kant and 20th century continental philosophy (such as Merleau-Ponty). The modern version depends on insights drawn from recent research in linguistics, cognitive science, artificial intelligence, robotics and neurobiology.


B) Origin of Solar system:

                            Many theories were postulated to describe the origin of the solar system & many of these theories actually stayed in the limelight of human attention for long periods of time. The initial theories provided the base for further development of concepts which seemed more plausible and worthy.
(1)  NEBULAR HYPOTHESIS—for many years the nebular hypothesis was a leading theory. According to it, the sun and its planets supposedly condensed out of swirling eddies of cold, dark, interstellar clouds of gas and dust.
(2) FISSION THEORY—the "fission theory" says that our sun burst one day, and all our planets came from it. Then the moons shot out from each planet, stopped, turned sideways and began circling the planets they came out of. Our moon is said to have emerged from an explosion in the Pacific Ocean.
(3) CAPTURE THEORY—the "capture theory" says that our planets and moons were wandering around in space and the planets were captured by the gravity of our sun, and the moons were captured by the planets.
(4) ACCRETION THEORY—the "accretion, condensation, nebular contraction," or "dust cloud" theory says that small chunks of material separately formed themselves into our earth and the moon.
(5) PLANETARY COLLISION THEORY—the "collision theory" of the origin our moon theorizes that our world is said to have collided with a small planet. The resulting explosion threw off rocks which formed our orbiting moon.
6) STELLAR COLLISION THEORY—the "collision theory" of the origin of our entire solar system suggests that our planets, moons, and sun all spun off from a collision between stars.
(7) GAS CLOUD THEORY—the "gas cloud theory" of our planets and moons teaches that gas clouds were captured by our sun, which then mysteriously formed themselves at a distance into planets and moons.
8) BIG BANG THEORY: -

In the 1930s Georges Lemaître had suggested that the universe might have originated when a primeval "cosmic egg" exploded in a spectacular fireworks, creating an expanding universe.. In 1946 the Ukrainian-born American physicist George Gamow considered how the early stage of an expanding universe would be a super hot stew of particles, and began to calculate what amounts of various chemical elements might be created under these conditions. Gamow assumed expansion and cooling of a universe from an initial state of nearly infinite density and temperature. In that state all matter would have been protons, neutrons, and electrons merging in an ocean of high energy radiation. Gamow and Alpher called this hypothetical mixture "Ylem" (from a medieval word for matter). Alpher made detailed calculations of nuclear processes in this early universe. It seemed that elements could be built up as a particle captured neutrons one by one, in a sort of "nuclear cooking."

9)STEADY STATE THEORY:-

The Steady State theory (also known as the Infinite Universe theory or continuous creation) is a model developed in 1948 by Fred Hoyle, Thomas Gold, Hermann Bondi and others as an alternative to the Big Bang theory (known, usually, as the standard cosmological model). In steady state views, new matter is continuously created as the universe expands, so that the perfect cosmological principle is adhered to. The theory requires that new matter must be continuously created (mostly as hydrogen) to keep the average density of matter equal over time. The amount required is low and not directly detectable: roughly one solar mass of baryons per cubic megaparsec per year or roughly one hydrogen atom per cubic meter per billion years, with roughly five times as much dark matter. Such a creation rate, however, would cause observable effects on cosmological scales.

 

C) Concept of Motion:

 

 

                      Newton’s laws of motion laid the foundations of classical mechanics and though Einstein’s theory of relativity took the sheen out of it, Newton’s laws still hold strongly in our class-rooms.
1.    Newton’s laws of motion

 

These are three physical laws that form the basis for classical mechanics. They are:

1.    In the absence of force, a body either is at rest or moves in a straight line with constant speed.

2.    A body experiencing a force F experiences an acceleration a related to F by F = ma, where m is the mass of the body. Alternatively, force is proportional to the time derivative of momentum.

3.    Whenever a first body exerts a force F on a second body, the second body exerts a force −F on the first body. F and −F are equal in magnitude and opposite in direction.

2.  Einstein’s Theory of Relativity

 

 

Special relativity

 

It is a theory of the structure of space-time. It was introduced in Albert Einstein's 1905 paper "On the Electrodynamics of Moving Bodies" .Special relativity is based on two postulates which are contradictory in classical mechanics:

1.    The laws of physics are the same for all observers in uniform motion relative to one another (principle of relativity),

2.    The speed of light in a vacuum is the same for all observers, regardless of their relative motion or of the motion of the source of the light.

•    The resultant theory agrees with experiment better than classical mechanics, e.g. in the Michelson-Morley experiment

that supports postulate 2,

    The defining feature of special relativity is the replacement of the Galilean transformations of classical mechanics by the Lorentz transformations.

 

 

 General relativity
General relativity is a theory of gravitation developed by Einstein in the years 1907–1915.

The development of general relativity began with the equivalence principle, under which the states of accelerated motion and being at rest in a gravitational field (for example when standing on the surface of the Earth) are physically identical. The upshot of this is that free fall is inertial motion; an object in free fall is falling because that is how objects move when there is no force being exerted on them, instead of this being due to the force of gravity as is the case in classical mechanics. This is incompatible with classical mechanics and special relativity because in those theories inertially moving objects cannot accelerate with respect to each other, but objects in free fall do so. To resolve this difficulty Einstein first proposed that spacetime is curved. In 1915, he devised the Einstein field equations which relate the curvature of spacetime with the mass, energy, and momentum within it.

                                        

Several theories survive simultaneously, due to their independent structure and domains and even science cannot be accommodated in just one theory, such that that theory could dislodge the rest of the domain specific theories. If we wish to be true to history and the practice of science, the correct picture of scientific knowledge requires not only a localization of meaning but also of truth. This localization of truth cannot be correct if the thesis of dislodgement of one theory by another is correct. Therefore, this apparent dislodgement stands in need of explanation.

 

References:

1.    http://en.wikipedia.org/wiki/Embodied_cognition
2.    http://en.wikipedia.org/wiki/Computationalism
3.    http://en.wikipedia.org/wiki/Steady_State_theory
4.    http://www.aip.org/history/cosmology/ideas/bigbang.htm#gamowverse
5.    http://en.wikipedia.org/wiki/Newton’s_laws_of_motion
6.    http://en.wikipedia.org/wiki/Theory_of_relativity
7.    http://gnowledge.org/~nagarjun/




posted by Jeenath
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Yes the same data can be supported by multiple theories for example

1. Enzyme – Lock and key model (Fischer), Induced Fit theory, Active site and substrate interaction

2. Theory of light – Newton’s Corpuscular theory, Huygens wave theory, Maxwell Electromagnetic theory, Plank’s Quantum theory

3. Structure of Atom – Dalton’s model, Thomson’s Plum Pudding model, Rutherford’s planetary model, Bohr’s Quantum theory

4. Geometry – Euclidian, Non-Euclidian

5. Cell Membrane Theory – Barrier theories (Quincke), Single layer model (Fricke), David Nicholson model, Davison and Danieelli model

6. Periodic Table – Lavousier, Dobereiner, Lothar Meyer, Newlands, Meendeleev and Meyer, Modern Periodic Table

7. Theories on the Structure of DNA – Lineus Pauling, Watson and Crick model

8. Theory of Evolution - Panspermia, Cosmic ancestry, Horizontal gene transfer, RNA world, Viruses, Darvinism, Neo-Darvinism, Lamarkism, Homologous organs, Mutation theory, Variations, Mendel's laws, Natural selection, Sexual differentiation, Coniditional intelligence, Random mating, Baldwinism, Speciation, Fossilization, Germplasm theory, Anthropology, Shift theory, Genetic drift, Recapitulation theory, Theory of Abiogenesis.

 Refrences

1.http://en.wikipedia.org/wiki/Light