so many questions that each of us may ask and which he will find the answer in this book full of exciting details.
When was the Universe formed?
Previously The Universe was smaller.
Long time ago ; all the galaxies of the Universe would have been contained in a small portion of space. Then a huge explosion would have occurred; and the galaxies would have spread in space. This explosion; called the “Big Bang”; would have occurred about 17.6 billion years ago; giving birth to The Universe.
What is space?
Space ; it is nothingness; or almost . It lies between the earth and the moon, between the planets of the solar system; between the stars. Virtually empty; it lacks air. In a space portion the size of a house; only a few atoms of different gases would be found; perhaps ; some particles of dust here and there; meteorites and comets pass through it.
Where does the space begin?
It starts above the atmosphere. The more one rises; the more the air becomes scarce. At an altitude of about 160 km; it is so tenuous that there is almost nothing left.
There begins the space. Only 160 km above your head.
Is the earth at the center of the universe?
The universe; it is all that exists: the set of all the planets; their satellites, the stars; galaxies (groups of stars). It extends in all directions. Can there be parts of the Universe that escape our telescopes? So we can not say whether or not the earth is in the center of The Universe.
What is “supporting” the universe?
The force that binds all the elements of the Universe to one another is the same as the one that makes you keep your feet on the ground: gravitation. It is exercised through space, between planets; the etioles and galaxies. It keeps the planets within the solar system and the etioles in their galaxies.