How Did The Universe Actually Begin?

The farthest reaches of the universe also hold its oldest relics. When we gaze upon the Andromeda galaxy, we’re peering back in time 2.5 million years. Even the glint of sunlight bouncing off Jupiter requires 30 minutes to journey to our eyes, while closer objects still appear with a delay. Scientists have traced the earliest light detected to a time when the universe was just a few hundred thousand years old, aiding in our understanding of the Big Bang. But what ignited this cosmic event in the first instance?The universe could have been hibernating before something set it in motion; it may have collided with another universe, or perhaps, it’s a part of an eternal cycle of cosmic bursts and rebounds. Why was the early universe invisible? How does energy define time, and why is 97% of the observable universe forever out of our reach? Could all this lead to another Big Bang? [LOGO] Trying to understand the universe’s origins, scientists use telescopes aimed at the furthest reaches of the cosmos. W hen these telescopes detect light from faraway galaxies, they’re essentially capturing light that began its voyage countless eons ago. This is because light requires time to traverse space. And since the universe has been expanding from its birth, the journey of that light has also been stretched out. The limit to how far back in time we can see is determined by the distance light has been able to travel since the universe started expanding. The very first photons couldn’t move freely, constantl y being scattered off free electrons, which made the early universe opaque. When everything cooled about 380,000 years after the Big Bang, these primordial photons were ‘set free’ and continued their journey in the direction they were moving at that moment. Over their long journey up until now, this light’s wavelength has stretched so much that it has shifted from the visible spectrum to the microwave range, something researchers discovered when they detected what is called the Cosmic Microwave Background radiation. Everything before this period of time is out of our observational reach. So scientists rely on projections to understand what might have occurred during the earlier stages of the universe.

Put simply, the energy spreads out, and becomes less usable. Stars go supernova, black holes slowly evaporate; hot things cool down, and even cold things heat up. Entropy dictates how we define time. Generally, what we refer to as the future is just a state of higher entropy or more spread-out energy, and a state characterized by lower entropy is what we call the past. So the further back in time we look, the lower the entropy should be. We don’t know why this is happening, but it’s something pre-Bang hypotheses’ revolve around. Some physicists propose that the universe before the Big Bang was hibernating. According to the idea, it remained compact and still throughout an everlasting past. Then, at a particular mome nt, a trigger initiated a change. This pre-Bang universe is thought to have been metastable, only appearing stable, while being inherently delicate. In the scientific community, this state is also known as a ‘false vacuum’. To understand the concept, picture a landscape with a valley nestled between towering mountains. People within the valley might believe it’s the most stable point. Yet, beyond the mountains lies a sheer drop to the sea, the true vacuum or an ultimate state of minimal energy. Similarly, the young universe could have existed in a state of false vacuum, until a catalyst triggered a transition into a truly stable state. So what was it that set the universe in motion? In the world of quantum mechanics, there’s a lot of uncertainty in the way particles act. If the pre-Bang universe was governed by the laws of quantum field theory, anything could have happened. Imagine an underground river running beneath the valley, slowly carrying away tiny pebbles into the sea. This con tinuous flow gradually weakens the valley’s foundation until a critical point is reached, and the valley caves in, and boom! This is how we believe the universe instantly expanded into what it is by the Big Bang. For a long time, the idea of a singular point containing all matter and energy was accepted. Today, modern physics suggests there was no such thing as singularity. Instead, the phenomenon responsible for our universe’s origin is cosmic inflation. It all started as a cold and empty space a hundred-billionth the size of a proton. Yet, it was brimming with so much energy, the pressures within produced a repulsive gravitational force. This force triggered an astounding expansion, where the universe doubled in size over 80 times, before resulting in fiery Big Bang. Think of a bomb that’s about to go off. First, the explosive material starts to break down, creating hot gasses and releasing energy. As gasses accumulate and spread out, they push against the walls of the bomb, creating pressure. Only then does the detonation take place. Similarly, all the energy used to fuel the universe’s inflation was released into space in a bang, heating it, and producing different particles. At that point, the universe has expanded to almost an octillion times its original size. Once focused and tightly packed energy became spread out throughout vast distances. However, entropy can also be interpreted as the tendency for all things to transition from a less likely state of order to a mor e possible state of chaos. But how can a seemingly organized universe we observe today, one filled with all the galaxy clusters and star systems, be more of a mess than the early ‘soup’ of extremely hot particles? Imagine the Big Bang as a party popper.

As you pull the string, it bursts into a dazzling display of confetti. We’d expect the confetti to scatter chaotically in all directions, forming a random assortment of colorful pieces. Yet what we see is the confetti organizing itself into perfe ctly shaped numbers and geometric objects—circles, squares, triangles, which represent subatomic particles, atoms, and molecules. And not just that, the universe appears to be uniform in all directions. Across its vast expanse, the universe has mysteriously consistent temperatures. Regardless of the direction researchers study, they measure a temperature of around 2.7° Kelvin throughout the cosmos. This is something that shouldn’t happen, and here’s why: Even though the age of the universe is an perature if these distant regions of space haven’t had enough time to exchange information yet? This is known as the horizon problem. Another puzzle is the flatness problem. Einstein’s theory of relativity reveals that massive objects curve space-time, influencing the motion of matter within it. Locally, stars, galaxies, and black holes cause irregularities in this space-time fabric. But when observed on a larger scale, these irregularities average out, resulting in a smoother structure. This ov well into this theory, but it doesn’t mark the beginning of the universe as a whole; only a tiny part of it as a result of quantum fluctuations happening on a much, much grander scale. Although life as a whole persists, there’s more of it with each passing moment. Let’s look at it this way. Every pocket universe runs out of energy, cools down, and ceases to exist. But at the same time, more of them are being created. And because every possible universe will exist, life would too, and there would osmic inflation theory has different variations. The model proposed by Alan Guth suggests that the expansion of the universe wasn’t constant. In its earliest phase, the universe was so small that the regions of space, that are now extremely far apart, were still close enough to exchange material. Then, space doubled and redoubled in size over 80 times within a fraction of a second, before the pace of expansion decreased, and continued in a more steady pattern. Even right now, the universe is qui le corner, things might seem uniform, like the flatness of space and the overall temperature equilibrium. But just like a wider view reveals the curvature of the Earth’s surface, a broader cosmic view could expose variations we don’t notice from our limited viewpoint. Before inflation, the universe might have had big temperature differences. As it expanded rapidly, some areas were pulled apart too far away to see, possibly concealing those variations from us. Or maybe, inflation stretched the un d of perpetually expanding for an infinite duration, the universe in the bouncing cosmological model would experience different phases of inflation and contraction. Each cycle starts with a Big Bang, a monumental burst of energy that launches a fresh era of cosmic evolution.

As the universe expands and evolves, it gives rise to galaxies, stars, and complex formations. However, with the passage of time, a mysterious force known as dark energy takes center stage. Its subtle sway grows stronger, eventually becoming the predominant force. As a result, the entirety of the universe begins to contract, with the observable horizon shrinking even faster, until it diminishes to a tiny point. As this boundary, beyond which events are obscured from our view, draws closer, our glimpse into the cosmos becomes increasingly limited.

First, distant galaxies would vanish from our sight, followed by stars within the Milky Way, then even closer objects like Mars and the Moon. Gradually, it will reach a point where people wouldn’t see things in their room, and then even the people would start to disappear! This p le or not depends on the overall curvature and density of our universe. If the fabric of space-time holds a significant quantity of energy and matter, this collective gravitational pull could make the universe ‘positively curved’, like a surface of a sphere. This curvature has a unique quality—it folds the canvas back onto itself, effectively slowing the universe’s ongoing expansion. And this might go one step further, reversing the expansion of space altogether. Everything would collapse in a B e bigger and bigger indefinitely. The universe’s ever-expanding nature lays the foundation for another intriguing hypothesis, one involving extra dimensions, and based on string theory. It is called ‘Brane Cosmology.’ Imagine all of existence as a giant cosmic book. Each page of the book exists in a lower dimension than the book itself. Scientists call these flat surfaces ‘branes’, and the idea is that they represent different universes, each doing its own thing based on a unique set of physical ntal units in physics. To understand these concepts, imagine a photon racing through space at the maximum speed possible – the speed of light. The photon is traveling a certain distance, a distance so short that it’s the smallest length that has any meaning in the universe. The Planck time is the precise duration it would take for this speedy photon to traverse the smallest indivisible distance, also known as the Planck length. Both of these units represent a measurement at the boundary of what on Kelvin within the core of a post-supernova neutron star pales in comparison to the magnitudes of the Planck temperature. Temperature serves as a reflection of a particle’s motion, energy, and vibrational intensity – essentially, the hotter it is, the more rapid the motion. Physicists believe this was the age of unpredictable quantum foam. Everything vibrated and changed randomly, giving rise to micro black holes and wormholes that would disappear as soon as they were created.

In the very dawn es of nature started separating from each other. The first one was gravity, which emerged as a distinct entity, shaping the universe’s future dynamics. The energy levels during this epoch were surging at a staggering 10 to the power of 28 electron volts. To put this into perspective, the universe was pulsating with a trillion times the energy achievable at our most advanced particle accelerator – The Large Hadron Collider. In a gradual cooling of the cosmos, the strong nuclear force finally brok This process, known as the Higgs mechanism, fundamentally shaped the future building blocks of matter. Somewhere along the way, baryogenesis, a crucial process in the early universe, occurred. Scientists don’t know the exact timing, but this hypothetical event is believed to have taken place when temperatures were so incredibly high that the random movements of particles happened at relativistic speeds. As particles and antiparticles collided, they annihilated each other. And somehow, matter dom By the end of this period, the universe was roughly 1 second old. [NUCLEOSYNTHESIS] Around three minutes after the Big Bang, temperatures plummeted to one billion Kelvin and below, allowing for nucleosynthesis. During this brief period, light atomic nuclei like hydrogen and helium were formed in abundance. Protons and neutrons combined to create these nuclei, setting the stage for future stellar processes that would produce heavier elements and pave the way for the formation of planets, stars, a erse without any obstacles. The emergence of neutral hydrogen and helium atoms allowed the first light to penetrate the cosmos, illuminating its history. The universe became transparent, allowing future human civilization to trace back time to this epoch. [DARK ENERGY & DARK MATTER] In the subsequent billions of years, as the universe evolved, dark matter—a form of matter that doesn’t emit light—presented its gravitational influence. Physicists believe that dark matter outweighs ordinary matter the mysterious forces of Dark Energy lead to a dramatic “Big Rip,”