2. Star Formation
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  1. The forces of matter

   Once science tells us about the universe as a great bonfire which started 13.700 millions of years ago, we could ask: how it becomes in what is today? Because in a bonfire only fire, ashes and hot temperatures can be founded. For that, science describes matter for what it does. You only know what a thing is by watching what it does. Science, then, observes, and classify only four levels of activity. These four levels or forces are the gravitational, the electromagnetic, the strong nuclear force and the weak nuclear force.

    First is gravitational force, which creates attraction between masses. If there is only gravitational force, everything ends shrinking into a small globe

    Electromagnetic force produces attraction and repulsion, and is stronger than gravitational force. We don’t feel the forces of electromagnetism: when I am nearer to a building, I don’t feel its force of attraction. Earth attracts us because of its huge mass, but I feel it only because of its planetary size. But electromagnetic force is near 10.000 trillion more powerful than gravitational force and is the one which makes matter hard and impregnable. When I clap my hands and they cannot merge, or when I am on the ground and I don’t sink on it, this is due to different attractions and repulsions that stopped a fusion between bodies.

    Electromagnetic force is what gives place to all the chemical reactions needed for life. Along with strong nuclear force and weak nuclear force, electromagnetic force produces atoms.

  A. Answer by clicking one of the letters: a, b, c. (If the letter takes the red color response is correct)

  1. Science describes matter by what it

    a. does
    b. thinks
    c. says


  2. How many ways of activities has matter?

    a. four
    b. three
    c. two


 3. It creates attraction between masses:

    a. strong nuclear force
    b. weak nuclear force
    c. gravitational


 4. It produces attractions and repulsions:

    a. electromagnetic force
    b. electromagnetic force
    c. strong nuclear


 5. Which one is stronger than the gravitational force?

    a. The strong nuclear force
    b. The weak nuclear force
    c. The electromagnetic force


 6. Chemical reactions are caused by the

    a. gravitational force
    b. electromagnetic force
    c. strong nuclear force


  2. The making of a star

   Atoms are groups of particles which are joined by electromagnetic or nuclear forces. The plainest atom only has a particle, the nucleus, and it is the hydrogen; the following has two, it is the helium; the next has six, the carbon; the next, eight, the oxygen. And the interaction between the four forces produces structures.

    After the explosionn, gravitational force slowly stopped its expansion and produced contractions in certain places. When a mass is bigger enough, gravitational force press the gaseous mass, mainly hydrogen and helium. This will be the earth of a star. A star is a globe of gas which, by its own gravitation contracts and become hotter, with a temperature of millions of degrees in its nucleus. And millions of degrees produced nuclear reactions. The Sun, for example, is a nuclear reactor, with a temperature of 15 million of degrees, and it transforms hydrogen, thanks to the four forces. During that process, the light and heat that we receive from the Sun are produced. The same happens with the rest of the stars.

    So there was a first age when stars were conformed, and there were a huge number of them, bigger than the Sun and a million of times brighter. They spent their combustible very quickly, and the following generation had a mixture of the elements synthesized in the first creation.

  B. Answer by clicking one of the letters: a, b, c.

  1. Electromagnetic, strong nuclear and weak nuclear forces form

    a. the molecule
    b. the structure
    c. the atom


  2. The atom with only one particle is the

    a. helium
    b. oxygen
    c. hydrogen


 3. The atom with six particles is the

    a. helium
    b. carbon
    c. oxygen


 4. The four forces produced

    a. structures
    b. rocks
    c. vegetables


 5. When a mass of gas is squeezed, appears a

    a. galaxy
    b. star
    c. supernova


 6. The Sun transforms hydrogen in

    a. helium
    b. carbon
    c. oxygen


  3. Formation of stars and planets

   Thousands and millions of stars could join themselves to become a galaxy, thanks to the gravitational force. Also, small galaxies could join to become a huge galaxy. These events happen while the Universe expands. As a result, we have a universe with over 100.000 million of galaxies. And a galaxy is like a city, a cosmic city with 100.000 million of stars, like the Sun. So the Universe is structured in large groups of thousands of galaxies, each one with thousands of millions of stars.

    When a star is formed, planets are formed from what is left over. The Solar System appeared 5.000 millions of years ago, and when the Sun attracted all the mass, a thousandth part conform the planets.

    As a result we have Earth, formed 4.500 millions of years ago by the formation of the Solar System. Once we have planets, we can find certain ones which are only rocks, as Earth, and their rocks have metallic elements. Other planets, as Jupiter, are almost exclusively gas, hydrogen and helium. This is important, because humanity cannot live in a planet formed by gas. So universe uses forces in the matter to arrange a cosmic hierarchy: galaxies, stars, planetary systems and, finally, a habitable planet, at least one, Earth. The process is long enough to last billions of years, thanks to the four forces of matter.     (Original text by F. Manuel M. Carreira S.J., astrophysicist and theologian)

  C. Answer by clicking one of the letters: a, b, c.

  1. Stars could join and form

    a. a universe
    b. a galaxy
    c. a planet


  2. From what is left around the star forming

    a. galaxies
    b. planets
    c. comets


 3. How many galaxies are in the Universe?

    a. 300.000 million
    b. 200.000 million
    c. 100.000 million


 4. It was formed 5.000 millions of years ago:

    a. the Solar System
    b. the Great Bear
    c. the constellations


 5. What planet is almost exclusively made of gas?

    a. Mars
    b. Earth
    c. Jupiter


 6. The habitable planet is

    a. Earth
    b. Mars
    c. Saturn


| Educational applicationsPhilosophy for young | In Spanish | Interactive |

®Arturo Ramo García.-Record of intellectual property of Teruel (Spain) No 141, of 29-IX-1999
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