Professor M. Ali Reza [Bangladesh]: Imam Gazzali wrote in the middle ages: A person who has no knowledge of space/universe, his taste of Iman is comparable to an impotent man who has no feelings of making love’s extraordinary extreme enjoyment. After completion of the punishment of Jahannam, hell, the least person would get space of Jannat [paradise] that is 10 times the size of the world. Then could we imagine the size of space for the best rank of heavenly people.
LATEST SCIENCE ABOUT THE UNIVERSE:
Three fourth part of Earth is water; half of the earth’s people live on one hundredth part of the land of Earth (recent report of NASA).Our Sun is an average ordinary star. The Sun is the closest star to Earth and the center of our solar system. The sun has been producing light energy for about 4.6 billion years and will do so for another 5 billion or so. The Sun measures 1.4 million km in diameter which means that 109 Earths could fit across its surface and 1.3 million Earths would fit inside it. The Sun is nothing but a star. On the other hand, a galaxy is a vast group of stars built together. It is estimated that there are 100-125 billion in the Universe . They are not scattered randomly but exist in clusters, vast distances apart. All the galaxies together take up just two millionths of space.
Size & shape of galaxies:
The largest are more than a million light years across (One light year =9.4 trillion km).The smallest, called dwarf galaxies, are a few thousand light-years wide.
Andromeda measures 250,000 light-years from side to side. Trillions of stars are arranged in one of four basic shapes: spiral, barred spiral, elliptical, or irregular. Each star follows its own orbit around the center of the galaxy. Stars in a spiral galaxy typically take a few hundred million years to make an orbit. A single galaxy is made of billions or trillions of stars. The most distant object that can be seen by the naked eye from the Earth is Andromeda galaxy which is 2.9 million light years from us.
In astronomical observations of stars, galaxies and other sources of light, we can determine how fast the sources are moving, either directly away from us or directly towards us, by measuring the Doppler shift of the light that reaches us. If a certain star were at rest relative to us, we would detect light from it with a certain proper frequency. However, if the star is moving either directly away from us or directly toward us, the light we detect has a frequency that is shifted from the proper frequency. This is due only to its motion directly toward us or away from us. If the source is moving away from us, the Doppler shift is called a red shift that is the wavelength increased. Thus it is possible to measure the relative speeds at which galaxies are approaching us or receding from us by measuring the shifts in the wavelength of the light they emit. If we look only at distant galaxies, beyond our immediate galactic neighbors, we find a astonishing fact. They are all moving away (receding) from us. In 1992 Hubble established a connection between the apparent speed of recession of a galaxy and its distance from us – namely, that they are directly proportional. It shows, the Universe has been expanding at the rate of 70 km per second. The discovery of the expanding of the Universe is one of the greatest revolutionary discoveries of the twentieth century.
More importantly, Al Quran narrates, “With power did We construct the Universe. Verily, We are able to extend the vastness of space thereof.” : Surah 51-Adh-Dhariyat; Ayat 47.
Again we see, all the galaxies together take up just two millionth of space. Even in the present context of the universe, 10 times of the Earth for the lowest one is nothing but a simple matter.
Writer: Former Associate professor of Physics, Jahangirnagar university, bangladesh. (30 May 2016)