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A structure is made up of interrelated parts functioning as an orderly whole. It is synonymous to the definition of a system. It implies that a force is present to hold all these parts together. There are four kinds of forces in nature:
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nuclei and even smaller particles. Note that the origin of friction, viscosity, elasticity, chemical bonding is electro- magnetic in nature. The internal structure of matter shields the electromagnetic force resulting in a residual force, which is weaker than the original. Similar shielding also occurs in the atomic nuclei resulting in a residual nuclear force.
The various structures in the universe are somewhat like a Russian doll. A larger size member would contain smaller ones in decreasing sizes (each with its special properties). However, while the relationship is "one to one" within the Russian doll, the hierarchical relationship is "one to many" in the cosmos. For example, the cosmos contains many superclusters, a supercluster contains many clusters of galaxies, a cluster of galaxies contains many galaxies, and so on. The Russian doll is just a special case of the general hierarchical organization. |
Evolution is the gradual development of a system from one form to another. For astronomical and biological systems it takes billions and millions of years respectively for their development into the present form. The history of modern science is simply too short to record the changes to these systems. However, with the aid of advanced observational technology, the evolutionary history of the cosmos can be reconstructed from astronomical objects in different stages of development. For the biological evolution, the fossil records and DNA comparison offer some helps to trace the evolution. In the absence of direct evidence, theory often offers some clues. There is no definitive answer to the cause |
of formation of orderly or complex structure from a seemingly homogenous environment. One scenario suggests that the initial requirement is the creation of fluctuation to move away from an equilibrium state . Such an open system would exchange matter and energy with its surrounding. Under certain circumstances, the open system reaches a steady state in which it is far from equilibrium and maintains that way as long as there is enough energy to support this naturally "improbable" arrangement. Living organism returns to dust (an equilibrium state) when there is no food (energy) to support the chemical activities within the body. |
Of the five senses in human to receive information about our environment, the sense of sight is the most important. Seventy percent of our sense receptors are devoted to the detection of light. This is not surprising in view of the dominant influence of Sunlight in our life. However, Sunlight occupies only a very small part of the electromagnetic spectrum which could shed information on various objects over the entire range (of the spectrum). It was only in the last hundred years that we were able to construct detectors for the retrieval of such information. Meanwhile we have also built telescopes to view distant | objects and microscopes for investigating the very small. Observation of astronomical objects can now be carried out in space to bypass the atmospheric effects such as infrared absorption, air turbulence, and overcast sky etc. Experiment is a special kind of observation when the objects can be controlled by human manipulation. It can yield knowledge not obtainable in the natural environment. Some phenomena such as the quantum uncertainty, and time dilation cannot be attributed to the poor quality of instrument. They are inherent in natural. |
While the Eastern culture emphasizes a holistic approach to view the world (see I-Ching), reductionism has been an important thinking in the West ever since Aristotle who mapped out sciences and formulated logic. This approach breaks up complex phenomena into pieces. It tries to understand the behavior of the whole from the properties of its parts. It greatly simplifies the investigation without the complication of external interference. The superscript in column one of Table 01-01 indicates how the universe is partitioned into different fields of study, which are further divided into various sub-fields. Theories in these various domains are often incomplete in the sense that there are parameters, which have to be measured. They may be explainable by the theory in the next level, but the parameters are seldom calculable due to mathematical complexity. | They are called effective theories, and invariably become invalid at smaller length (size) scale. The method to address this kind of problem is called "renormalization". Ideally, the ultimate one associated with the smallest length scale (the Planck length) should be self-contained, it is sometimes referred to as the primary theory (or theory of everything). It will not need external inputs and shall be able to explain all the effective theories. Conversely, the whole becomes not merely more, but is very different from the sum of its parts. It is referred to as the emergent phenomenon, which possesses special properties such as: radical novelty, coherence, supervenience (derived from something), self-organization, manifestation at global or macro level, and the capability to evolve - the living world is a good example. |
The scientific tools include measurement, analysis, inference, logic, hypotheses, and theories. Since Isaac Newton invented calculus in the 1690s, the development of differential equation for various physical systems has become a powerful tool for theoretical physicists who are very creative in modeling. For example, the entire galaxy is | considered to be a particle in cosmological model. This is justifiable as long as the size is much smaller than the distance between the objects. Modeling is used to simplify the system in order to arrive at a solvable equation. It usually involves making an assumption; then works out the consequence, which is finally verified by experiment or observation. |
It turns out that only linear equation (an equation appears in first degree only for the dependent variable and its derivatives) is suitable for isolated system as envisioned by the method of reductionism. In case it is applicable, it becomes a very efficient tool for compression, which would encrypt voluminous information into a few equations. Nonlinear equations can simulate some complicated systems | in the "real-world", but seldom offer solution in simple form. Other branches of science (such as biology), which are not susceptible to this kind of treatment, have to rely on terminology to shorten the description. Unfortunately it is very difficult for the layman to decrypt the compression, and it has become a communication barrier¶ between science and the outside community. |
There are fifteen topics in this webpage including the Introduction. Following is a table to summarize the remaining fourteen topics, which are ordered in decreasing size of the structure. The table displays the averaged size or a range in size of the structure, the mass or energy of the individual object, the epoch of first appearance (the zero time is at the moment of the Big Bang), the dominant force in holding the system together, and the associated physical phenomena. Since the data involve very large and very small numbers, they are presented in power of ten. For example, 1000 = 103 and 0.001 = 10-3 (refer to "Units and Constants" for more information about unit conversions and universal constants). The epoch of first | appearance reflects the evolution of three groups of objects. The first group contains objects of small size from elementary particles to molecules (the micro-world); their evolution occurred at the beginning of the universe. The second group is represented by astronomical objects from stars to superclusters (the macro-world). It is believed that these objects evolved in the "bottom up" process in which smaller units merge and form larger units. Life on Earth belongs to the third group (the living-world including Earth and the organisms living on it), which materialized only recently (on astronomical scale) in the last 4.5 billion years. |
Topic | Size | Mass/Energy | First Appearance | Force and Phenomena |
---|---|---|---|---|
Macro-world | ||||
Observable Universe a | 1.3x1028 cm ~ 4000 Mpc. (cosmic horizon) |
4x1022 Msun (including dark energy, ordinary and dark matters) |
0 sec. | Gravity + Unknown repulsive force; an expanding space in the last 13.7x109 yrs, containing all the mass/energy of this world |
Superclusters a | 1026 cm. | 1016 Msun | 11x109 yr. | Gravity; largest scale of lumpiness |
Clusters of Galaxies a | 1024 cm. | 1015 Msun | 6x109 yr. | Gravity; galaxies in orbit around each other + dark matter |
Galaxies a | 1022 cm. | 1011 - 1014 Msun | 7x108 yr. | Gravity; aggregation of stars, gas, dust and dark matter |
Star Clusters a | 1020 cm. | 102 - 106 Msun | 5x108 yr. | Gravity; group of stars originated in an interstellar cloud |
Planetary Systems a | 1016 cm. | 0.1-100 Msun | 1.8x108 yr. | Gravity; system of non-luminous bodies as by-product in stellar formation |
Stars a | 1011 cm. | 0.1-100 Msun | 1.8x108 yr. | Gravity; contracting lump of gas with luminosity maintained by nuclear burning |
Earth g | 109 cm. | 6x1027 gm. | 9.5x109 yr. | Gravity; a planet in the habitable zone of the Solar system | Living-world |
Multicellular Organisms b | 104 - 10-1 cm. | 107 - 10-3 gm. | 13.5x109 yr. | Residual Electromagnetic force; organisms composed of multiple cells |
Unicellular Organisms b | 10-1 - 10-4 cm. | 10-3 - 10-12 gm. | 10.5x109 yr. | Residual Electromagnetic force; one cell living unit | Micro-world |
Molecules c | 10-5 - 10-8 cm. | 10 - 10-3 ev. | 3.8x105 yr. | Residual Electromagnetic force; structure formed by combination of atoms |
Atoms c | 10-8 cm. | 10 ev. | 3.8x105 yr. | Electromagnetic force; system of electrons and nuclei |
Nuclei p | 10-13 cm. | 109 ev. | 1 sec. | Residual strong force; system of neutrons and protons |
Elementary Particles p | 10-16 cm. > | 10-3 - 1012 ev. | < 10-32 sec. | Weak, strong and electromagnetic forces; basic constituents of matter and force |
Nature Outlooks | |
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