The crossing star theory (Chamberlain and Moulton 1905) The assumptions of the crossing star theory assumed that the solar system was originally the Sun, A huge star approached to the Sun, This star attracted...
The solar system consists of the Sun (star), Eight planets (revolving around the Sun in fixed orbits), the comets, the asteroids, and the moons (the satellites of the planets), It was considered as the...
Big Bang is a massive explosion that happened, since 15000 million years, resulting in it all the forms of matter, energy, and time, It is the expansion of the universe and merging of atomic...
The universe is a wide and extended space that contains all the galaxies, the stars, the planets, the moons, the living organisms, and everything, The universe is very vast, The Sun and the earth...
The weight The reason of object’s falling downward the Earth is a type of force called the weight (the gravitational force), and you can feel this force when you carry an object or try...
The ozone layer The ozone layer is located at the height of 20 to 40 km above the sea level, And it is located in the lower part of the stratosphere layer, As it...
