After the sixth phase, the typical characteristic in the universe was a temperature that reached as high as 4,000 C. At that temperature space was not as dark as it is today, rather it gleamed brightly. As matter condensed into gases and cooled down as time passed, the density values increased and the planets that we know today started to form out of the increasingly solidifying matter. The universe, presumably, was still a homogeneous gas cloud of helium and hydrogen when it reached an age of 700,000 years. Yet, the universe did not become a single galaxy by collapsing on a single point; rather billions of galactic centers were created. So, what made the universe wait as a gas cloud in just that state? Why did it not collapse in on a single point?
While cosmology has been asking this question for years, Roger Penrose, a theoretical physicist and black hole expert, tried to compute the first creation power in one of his studies in 1973. Some tiny particles, smaller than a proton, were discovered. Those particles had been formed not by the collapse of the stars, but during the first creation after The Big Bang. Although those tiny black particles were far smaller than atoms, they behaved like black holes and swallowed everything they encountered. Yet it seems that they left their footprints as they passed. It seems as if hydrogen and helium clouds had gathered around those enormous attraction centers and the cores of billions of galaxies had thus formed. The universe was being shaped and was expanding from particles made up of a cosmic soup, a gas cloud. The Qur’an also relates the great transformation that took place in shaping the universe:
Have the unbelievers not beheld that the heavens and the earth were a solid mass, then We separated them; and of water We produced every living thing, will they not believe, then? (21:30)
From Dust and Gas Clouds to Cosmic Systems
Stars, like living beings, grow older and demise. They go through an infancy, then youth and adulthood. Some gas and dust clouds, known as Nebulas lie among galaxies. Nebulas are considered to be the raw material of stars. In our galaxy, the Milky Way, gas and dust clouds are mostly located on the spiral arms that extend outward. An impact, called a shock wave, causes interstellar matter to come together and condense into huge clouds and spheres in space. The clouds that condense during the first formation of stars are so thin that they do not even have gravitational effect. Due to this lack of gravity, it has not yet been fully understood how these gas and dust clouds came together and condensed.
A condensed cloud heats up due to the collisions within it; these collisions increase as the cloud is compressed in a process that lasts millions of years. These collisions cause the cloud to sparkle and gleam. Initially, some rays, such as infrared or radio waves, are emitted.
While the star forms, the outer crust collapses very slowly, whereas the central parts collapse at a much greater rate. As the cloud condenses farther, it emits more light and starts to shine inside the dark, dusty covering that surrounds it. This nuclear cooking-pot, which has a temperature of 10 million C at its core, sparkles. With the flaring of the star, a disk forms around the newly created center. Strong winds, triggered by the powerful hot gases that are emitted from the upper and lower surfaces of the disk, blow in opposite directions; they sweep away most of the original gas cloud that formerly impeded the visibility of the new star. Thus, the star begins to be visible through an ordinary telescope. The energy produced in the center of the star after it has been formed and reaches a certain age, impedes greater collapse. This energy provides the necessary pressure to block the collapse of matter and seeks a way to escape. Hence, the star reaches an equilibrium.
We cannot observe stars being born in interstellar gas clouds with normal telescopes. This is because the gases in space and within the dust clouds act like the particles in cigarette smoke and absorb the light. Thus, we see the clouds as dark silhouettes on the surface of the star. Formations of stars can only be observed through infrared telescopes. An infrared telescope was first placed on a satellite sent into orbit in 1983. That telescope discovered thousands of young stars hiding in the depths of interstellar clouds.
A condensed gas cloud needs to be of a certain size in order to become a star. If the gathering gas clouds are not large enough, a different situation occurs: a planet is born! The stars and planet systems that orbit the stars are formed in this way. While stars are being formed, the planets are made out of smaller gas clouds.
The Sun is a typical small star that is relatively very young. We can see stars in space that are up to a hundred times as large as the Sun, or ones that are one-tenth its size. When stars are compared to the Sun, the dimmer ones that have a surface temperature of only 3,000 C are at the bottom of the range, while ones similar to the Sun, with a surface temperature of 6,000 C, occupy the middle range. Stars that are much larger than the Sun have a surface temperature surpassing 30,000 C. Contrary to general thought, larger stars live shorter lives, because the denser and the hotter the core is, the more intense are the nuclear reactions that take place.
Thus, these stars have brighter surfaces. A massive star that uses more nuclear power is more likely to run out of fuel sooner. On the other hand, a smaller star that uses its fuel sparsely has a longer life, even though it has less fuel. We know that there is a simple relation between the temperature and the pressure of a gas. If we heat up a gas in an enclosed container, the pressure will increase; if we cool it down, the pressure will decrease. When you think of a star with a temperature reaching millions of degrees Celsius at its center, you can understand how great the pressure is there. We know that heat is being produced through nuclear reactions. Every star is under the influence of an attraction force that approximates and compresses the elements of the atoms it contains. As the mass of the star increases so does the attraction force. This inward force is balanced by the force of outward nuclear explosions. The most significant reaction that ensures the vitality and continuity of the star is the transformation of hydrogen into helium through fusion. Yet, while this happens, the fuel lessens and the reactor will fail to function properly. At this point, the force of the pressure keeping the star in a balance is endangered and the star begins to lose its long struggle against the attraction within its mass.
As stars lose their fuel, they are exposed to different “deaths,” in proportion to their mass. The number 1.44 is the coefficient related to the mass of the Sun. Stars with a mass of less than 1.44 times the mass of the Sun become black or white dwarves, whereas those with a mass of more than 1.44 times the mass of the Sun become supernovas, neutron stars, and eventually black holes. If the mass of a star is more than 1.44 times the mass of the Sun, it will not remain as a dwarf. Its inner temperature and density will increase and the fuel, in the form of iron, nickel, chrome and cobalt, will not be able to burn anymore. Temperature and pressure turn the electrons and protons into neutrons by adhering them to one another. The iron core becomes a huge ball with a diameter measuring 100 kilometers. At a critical temperature the star explodes, emitting a billion times its normal light intensity. This is a supernova explosion. With the explosion, a terrific shock wave and the flow of neutrino (an elementary particle with zero charge and zero mass) spreads. The materials produced in the explosion flow into space as gas clouds.
The Event of the Supernova and the World
As a matter of fact, at one time we were physically part of a star. That star was probably larger than the Sun and was formed right after the creation of the universe, namely in the first few hundred thousand years.
At those times, the universe was almost completely made up of hydrogen. The solar system and the earth had been formed of this element. Hydrogen was the beginning of everything, and whatever material was available in the universe had been derived from the hydrogen atom. Only after being processed in the nuclear furnace for billions of years did hydrogen turn into helium.
Consequently, the star’s life was over. As the fuel in the depots was running out, demise emerged on the horizon. It began in fits and starts, and then when the furnace was about to go out, the mass of the huge star collapsed in on itself. Having increased in size after the collapse, the pressure triggered new nuclear reactions. Thus, a series of elements, ranging from carbon to iron, came to be part of the body. Finally, the star gave its all with an enormous explosion that we call a supernova. A billion-year life ended in just a few seconds. Atom particles at the core of the star melted and turned into neutrons in just a few seconds, and the parts closer to surface were thrown into space at a speed of ten million kilometers per second. It was a magnificent moment in which billions of degrees of heat was produced and in which a great light, as bright as one billion suns, shone. Some of the elements that are heavier than iron were also created during that time.
Supernova means death to a star. The enormous energy once unleashed heats up the outer layers of the star so much that the way is paved for new fusion and energy-absorbing reactions to occur instead of energy-freeing ones. Not only iron, but also other heavy elements, such as gold, lead, and uranium are manufactured in this furnace. These elements are thrown into space together with pre-synthesized and lighter ones, like carbon and oxygen, and combine with the wreckages of other supernovas. During the succeeding millenniums, new star and planet generations are created.
For our planet, fantastic and extraordinary cosmic events, such as supernovas, have been the starting point for the existence of some elements, like oxygen, gold and silver, and ultimately for the creation of life. The sources of carbon and oxygen that are essential to life, the silver and gold rings that we wear on our fingers, the lead plates on our roofs, and the uranium that fuels our nuclear reactors are all results of the death throes of stars that died prior to the birth of the Sun.
As we have seen, a supernova explosion causes matter to move from one point to another. As a result of such explosions, many of the remnants of stars are spread over space and new stars or star systems are created by the accumulation of such remnants. The Sun and the planets in our solar system and surely those in our universe exist as the result of a very early supernova. In this immense universe which houses humanity, the transformation that matter undergoes, and the gradual advance toward a certain destination, all indicate that the Divine Knowledge, Power and Will are intermingled with His Compassion and Grace.