Stars: The Unsung Marvels of the Cosmos

Introduction

When we look up to the night sky and see the countless ‘white dots’ scattered across the expansive black canvas of space, we are quick to overlook the impossible complexity of these astronomical marvels. From the first elements produced in their core, the very same elements that run through our veins, to their glorious and meticulous deaths. Stars are a true and constant reminder of the unmatched beauty of God’s creation; intricately fashioned by His infinite knowledge. It is the Stars that provide the very little light in the, otherwise, boundlessly dark universe; providing inextinguishable warmth to their systems lest they are consumed by the cruel coldness of the cosmos.

وَلَقَدْ جَعَلْنَا فِي السَّمَاءِ بُرُوجًا وَزَيَّنَّاهَا لِلنَّاظِرِينَ

And We have, indeed, made mansions of stars in the heaven and have adorned it for the beholders.

The Holy Qur’an (15:17)

It can only be human ignorance that overlooks this divine adornment; that leaves such grandeur and majesty unnoticed. Thus, we must learn to appreciate these unsung marvels of the universe lest we become ungrateful. With this in mind, let us try to understand these cosmic powerhouses; from the moment they are born to their bittersweet death and all that is in between. For that, we must travel to a time of unfamiliarity, just mere seconds after the Big Bang.

Stellar Genesis

During its extremely early stages (spanning hundreds of millions of years) the universe was a 10-billion proverbial sea of neutrons, protons, electrons, anti-electrons, photons and neutrinos. In other words, it was an incredibly hot and hazy mess; simply too hot for any star1 to ever form. Over the next few hundreds of millions of years, as the universe cooled, clouds of helium and hydrogen began to coalesce and gravity began pulling the smaller clumps together forming larger and larger clouds; accommodating two incredibly vital elements: Hydrogen and Helium; the framework of stars. These celestial clouds began to grow to incredible masses until eventually collapsing under their own weight consequently giving birth to the first ever stars. These stars exploded into existence and covered the incredibly dark universe in a newfound light for the first time since the ‘Big Bang’. These stars then formed clusters which formed galaxies and, in those galaxies, gravity pulled rock and gas together which formed planets which then formed solar systems. Thus, over billions of years, the once messy and congested universe began shaping itself into the universe we know today.

The Life of a Star

Now that we know how the earliest stars came into existence, let us begin to understand what a star really is and what it does. Stars, as mentioned before, are cosmic-level powerhouses and so, the life of a star can be truly unforgiving. From the moment of their birth, Stars begin their lifelong purpose of consistently and constantly radiating heat and light to their neighbouring planets. If we take into consideration that the estimated average lifetime of stars is in the hundreds of millions of years, it is mind-blowing when you comprehend just how much energy one star will produce in its lifetime. From an outside perspective, Stars seem to be very simple objects; a very bright ball and while that’s not far from the truth, they are a little more complicated than that; Stars are a sphere of plasma that are held together by their own gravity. But if you were to cut a star in half, it is then that the true intricacy of these marvels of nature will reveal itself.

A cross-section consisting of varying layers and colours would be seen and within each compact layer of a star, incredibly valuable elements are formed under intense but perfected conditions. Hydrogen, helium, carbon, oxygen, neon, silicon and even in some cases iron; the very foundation stones of the universe are created in these cosmological nuclear powerhouses. It is this constant fusion of elements that produce the consistent heat and light to the stellar systems; just like their Gracious Creator, these cosmic marvels go about their incredibly long life taking nothing but giving everything. Without stars, the universe would be a much, much darker, colder and emptier place, more so than it already is.

Death and Beyond

Although millions of years may sound like an eternity to us, on the 13 billion-year timeline of the Universe, a star’s life is relatively short-lived. After burning away viciously for millions of years; the forces holding a star together undergo a weakening and thus, the star begins its dance with death. However, unlike our slow and withering descent into the grave, stars die in a very dramatic fashion, either shedding off their outer layers to create beautiful Planetary Nebulae or going out with a very literal bang in the form of supernovae. The former or latter is a fate decided by the mass of the star and both are incredibly unique in their own way.

Scenario 1: Planetary Nebula

The first form of stellar death is the Planetary Nebula. Amongst the most beautiful creations of Allah, the Planetary Nebula is a considerably calm and slow death for stars. This form of death is the end for smaller stars like our Sun and so, to easily understand just exactly what happens, we will fast forward 5 billion years to the beginning of the end of our beautiful Sun. Just like every other star, the Sun will begin to burn through its Helium and Hydrogen quickly making the outward push stronger than gravity and thus expanding in size. At this stage, our Sun will become a ‘Red Giant’ growing big enough to engulf Mercury, Venus and even the Earth. It will then begin burning through heavier and heavier elements, from the lightest helium to the heaviest carbon, however, unlike the Red Supergiants, smaller Red Giants are not dense enough to fuse Iron and thus, after burning through all the remaining helium, the fusion will stop and the Sun will collapse in on itself due to its gravity. This collapse will not be violent like the Red Supergiant due to the lack of mass and nuclear reactions in the core; instead, the Sun will become a white dwarf, shrinking down to the size of Earth while retaining its mass. Its outer layers, made up of varying elements, will be pushed out into space and, over time, become a Planetary Nebula. These marvels of nature are each a work of unique art; not only are they the most beautiful objects in space but Nebulae such as the ‘Pillars of creation’ serve as nurseries for new stars.

Most recent image of the pillars of creation captured by the James Webb Telescope
The most recent image of the Pillars of Creation captured by the James Webb Telescope

The white dwarf remnant of this death will remain for another 4 billion years slowly burning up its fuel and eventually fading into a black dwarf, a lifeless orb of no energy floating through space. As of now, however, we have not discovered any black dwarves as it is still too early on the timeline of the Universe.

Scenario 2: Supernova

Artist’s impression of a supernova, ESA/Hubble, CC BY 4.0, via Wikimedia Commons

The second form of stellar death that we will look at is the supernova, an astronomical explosion bright enough to be seen around the universe.

So, what exactly causes this explosion? To understand the science behind this, we must once again take a look at a cross-section of a star. The fusion that takes place in the central layers generates an immense amount of energy, energy produces heat and heat produces pressure which creates a powerful outward pushing force. At the same time, the immense gravity of the star pulls inwards; a battle of the forces results in an equilibrium, a state of balance which holds the star together. As the star ages, this equilibrium begins to stutter as the star’s fuel begins to run dry weakening the outward push and thus, allowing gravity to collapse the star.

This collapse causes a supernova and is the form of death for Red Supergiants, i.e., the latter stage of a massive star. Like all stars, massive stars release energy by fusing elements together, however, massive stars use up their supply of hydrogen much more quickly than smaller stars (within 5 – 20 million years). The star then begins fusing the helium inside its core which allows it to create much heavier elements, like carbon and iron but at a cost; these changes in the fusion process release huge amounts of energy causing the star to expand. As the star gets bigger, the heat is spread over a larger area, so the surface cools down and glows with a redder colour hence the name ‘Red Supergiant.’

Supergiants burn all the helium in their cores within a few million years and then start to burn carbon and then oxygen and then nitrogen etc. This continues with heavier and heavier elements until the star begins to form Iron. Up to Iron all elements release energy when they are fused, but Iron needs energy to be fused, so after iron & nickel are created in the core, the end is near for the star. As the iron cannot be fused completely, it begins to build up inside the core until the core itself becomes iron. It is at this moment that the relentless fusion, which has been ongoing since the birth of the star, comes to a halt resulting in the loss of the outward force produced through fusion and thus breaking the equilibrium. The outer edges of the core collapse inward at 70,000 meters per second, about 23% the speed of light and in just a quarter of a second, infalling material bounces off the iron core of the star, creating a shockwave of matter propagating outward. This shockwave can take a couple of hours to reach the surface but once it does, it creates the largest explosion mankind has seen in the form of a supernova. It can take months for a supernova to reach peak brightness but when it does, it is capable of even outshining galaxies!

The remnants of this extreme death are two of the wildest creations of nature: either a Neutron Star or a Black Hole.

Neutron Stars

As mentioned previously, Neutron Stars are the remnants of Supernovas; these are truly a freak of nature. When the core of a Red Supergiant collapses, it condenses the mass of a whole star into a ball the size of a city which, when put into perspective, truly boggles the mind. For example, if you were to have a marble-sized chunk taken from a neutron star, it would weigh as much as Mount Everest. These stellar remnants are also spinning at incredible speeds; some as fast as the blades in a kitchen blender, combined with magnetic fields trillions of times stronger than the Earth.

Black Holes: The Cosmic Lawbreakers

Einstein’s Theory of Relativity helped introduce the concept of ‘Space-time’ which, simply put, explains that the cosmos is vaguely like a 4-dimensional rubber fabric. This fabric is capable of bending and twisting just like any fabric that we know. Massive objects – like the Earth or Sun – create small distortions in space-time that cause it to bend and curve; celestial orbits, like the moon for example, are done around the curves of these distortions. Black Holes, on the other hand, are a region of Space-time where the gravity is so strong that its distortion brings this fabric to a ripping point.

First image ever taken of a black hole, Event Horizon Telescope, uploader cropped and converted TIF to JPG, CC BY 4.0, via Wikimedia Commons

Secondly, this gravitational pull of a Black Hole gets exponentially stronger as you get closer to the event horizon (the absolute point of no return). This means that if, in theory, you were to approach the event horizon feet first, they would be pulled away from the rest of your body at an atomic level continuing until your whole body became a single string of atoms.

This process is aptly named ‘Spaghettification’ or ‘Noodle Theory’ by astrophysicists.

Furthermore, since space and time are relative (hence the term Space-time), time around a black hole behaves incredibly differently. The intensity of this time distortion depends on one’s distance from the Black Hole. In less severe scenarios, being in relatively close proximity to a Black Hole would slow our passage of time to the extent that days for us could be months or even years for others. This effect becomes much more extreme as we get closer to a black hole. For example, let us assume that someone (for the sake of science) willingly offered to throw themselves into a black hole and they promised to flash a light in your direction every second of their journey towards it. As they get closer and closer to the Black Hole, you would see them getting slower and slower; the intervals between the flashes growing longer and longer, until they reached the event horizon. At that point, for us, they would completely freeze in place and the flashes would stop; for them, however, time would be passing completely normally as they proceed to be swallowed by the black hole. If we watched for long enough, we would see their frozen projection slowly turn red until suddenly disappearing out of sight. The majority of what we know about space is based on theories born from the laws of physics; laws that we thought were absolute. When black holes were first theorised to exist, (only recently confirmed to exist because of the first-ever picture of one) they defied not only logic itself but the very laws of physics as we knew them. However, considering how little we know about the universe, it was bold of us to assume that the universe would function according to our created laws. The truth is, it does not and it never will. The secrets of the creation of the cosmos lie with our Creator and we will only uncover that which He allows us to.

وَأَنَّا لَمَسْنَا السَّمَاءَ فَوَجَدْنَاهَا مُلِئَتْ حَرَسًا شَدِيدًا وَشُهُبًا

‘And we sought to reach heaven, but we found it filled with strong guards and shooting stars.’

The Holy Qur’an (72:09)

An average human blink is 250ms. Is it not astonishing that in just a fraction of this time, grand cosmic events will happen all across the universe; 15,000 stars will be born, 300 stars will explode and 30 enigmatic black holes will come into existence? Closer to home, the Sun will burn through 175,000,000 tons of hydrogen producing 96,100,000,000,000,000,000,000,000 Jules of energy… all in the time it takes for a human to blink.

So the next time we look up to the night sky and see the countless ‘white dots’ scattered across the expansive black canvas of space, we should be grateful for the beautiful sight that we behold as there may be a generation of humans in the future that may look up to a dark and empty universe. Their simplicity and uselessness are nothing but an illusion. The reality is that everything in this universe is irreplaceable, a cog in the flawless machine of the Cosmos. On the human timeline, we are incredibly new to studying space, to discovering the countless beauties that Allah has bestowed us with. With every new discovery mankind makes, it should add a new factor in strengthening our belief in God because behind all the beauty and awe-inspiring objects in the universe is an Omnipotent Creator.

“If you love the art you must love the artist; if you love the creation you must love the creator”

Hazrat Khalifatul Masih IV (rh)

Disclaimer

This article was originally published in the Annual Printed Edition of Majallatul Jamia

Ehtesham ul Islam

Ehtesham ul Islam

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