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A brief history of the Ptolemaic System.

Ptolemaic System
In his Dialogue Concerning the Two Chief World Systems, Ptolemaic and Copernican of 1632, Galileo attacked the world system based on the cosmology of Aristotle (384-322 BCE)and the technical astronomy of Ptolemy (ca. 150 CE).

In his books On the Heavens , and Physics , Aristotle put forward his notion of an ordered universe or cosmos. It was governed by the concept ofplace , as opposed to space, and was divided into two distinct parts, the earthly or sublunary region, and the heavens. Theformer was the abode of change and corruption, where things came into being, grew, matured, decayed, and died; the latter was theregion of perfection, where there was no change. In the sublunary region, substances were made up of the four elements,earth, water, air, and fire. Earth was the heaviest, and its natural place was the center of the cosmos; for that reason theEarth was situated in the center of the cosmos. The natural places of water, air, and fire, were concentric spherical shellsaround the sphere of earth. Things were not arranged perfectly, and therefore areas of land protruded above the water. Objectssought the natural place of the element that predominated in them. Thus stones, in which earth predominated, move down to thecenter of the cosmos, and fire moves straight up. Natural motions were, then, radial, either down or up. The four elementsdiffered from each other only in their qualities. Thus, earth was cold and dry while air was warm and moist. Changing one orboth of its qualities, transmuted one element into another. Such transmutations were going on constantly, adding to the constantchange in this sublunary region.

Ptolemy

The heavens, on the other hand, were made up of an entirely different substance, the aether

The traditional English spelling, aether, is used here to distinguish Aristotle's heavenly substance from the modernchemical substance, ether.
or quintessence (fifth element), an immutable substance. Heavenly bodies were part of spherical shells of aether. Thesespherical shells fit tightly around each other, without any spaces between them, in the following order: Moon, Mercury,Venus, Sun, Mars, Jupiter, Saturn, fixed stars. Each spherical shell (hereafter, simply, sphere) had its particular rotation,that accounted for the motion of the heavenly body contained in it. Outside the sphere of the fixed stars, there was the primemover (himself unmoved), who imparted motion from the outside inward. All motions in the cosmos came ultimately from thisprime mover. The natural motions of heavenly bodies and their spheres was perfectly circular, that is, circular and neitherspeeding up nor slowing down.

It is to be noted about this universe that everything had its natural place, a privileged location for bodies with aparticular makeup, and that the laws of nature were not the same in the heavenly and the earthly regions. Further, there were noempty places or vacua anywhere. Finally, it was finite: beyond the sphere of the fixed stars and the prime mover, there wasnothing, not even space. The cosmos encompassed all existence.

Christian Aristotelian Cosmos. From Peter Apian, Cosmographia

Questions & Answers

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They formed in two ways first when one sperm and one egg are splited by mitosis or two sperm and two eggs join together
Oluwatobi
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Genetics is the study of heredity
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the study of living organisms and their interactions with one another and their environments
AI-Robot
the study of living organisms and their interactions with one another and their environment.
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discuss the biological phenomenon and provide pieces of evidence to show that it was responsible for the formation of eukaryotic organelles in an essay form
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list any five characteristics of the blood cells
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lack electricity and its more savely than electronic microscope because its naturally by using of light
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advantage of electronic microscope is easily and clearly while disadvantage is dangerous because its electronic. advantage of light microscope is savely and naturally by sun while disadvantage is not easily,means its not sharp and not clear
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cell theory state that every organisms composed of one or more cell,cell is the basic unit of life
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is like gone fail us
DENG
cells is the basic structure and functions of all living things
Ramadan
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ISCONT Reply
is organisms that are similar into groups called tara
Yamosa
in what situation (s) would be the use of a scanning electron microscope be ideal and why?
Kenna Reply
A scanning electron microscope (SEM) is ideal for situations requiring high-resolution imaging of surfaces. It is commonly used in materials science, biology, and geology to examine the topography and composition of samples at a nanoscale level. SEM is particularly useful for studying fine details,
Hilary
cell is the building block of life.
Condoleezza Reply
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Aron Reply
Diversity of living thing
ISCONT
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Cell division is the process by which a single cell divides into two or more daughter cells. It is a fundamental process in all living organisms and is essential for growth, development, and reproduction. Cell division can occur through either mitosis or meiosis.
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Source:  OpenStax, Solar system. OpenStax CNX. Jun 29, 2007 Download for free at http://cnx.org/content/col10432/1.1
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