The Dark Unseen Mirror

Wednesday, July 8, 202635 min read

physics

Have you heard about the theory of a multiverse before? We bet you have (we might be wrong if you are a dull and boring person with 0 life). Well, this theory suggests that there are more universes along with our own universe. However, even with so much advanced technology and satellites, we haven’t detected any signs of this. In fact, we are still searching for signs of life beyond our planet and solar system. The reason for not detecting any such signals is suggested as to be the result of Dark Matter. What is Dark matter? It is such a matter (atoms and substances) that our technologies cannot detect at all, they are completely invisible. And according to many scientists, Dark matter is an unavoidable part of our universe(s), and it is natures’ law itself that they are undetectable by external beings/technologies. Sounds interesting, huh? But envision this: There is something is the very room you are sitting, right beside you, and something else right behind you. You cannot see it, but sometimes when you actually ‘feel’ that there is another unseen presence in your room, it might actually be true, and could be triggered by Dark matter and the beings emerging from it (Do not look behind, it’s no use!).

From stars and galaxies to the shoes on your feet, ordinary matter makes up everything we can see in the universe — in wavelengths spanning from the infrared to visible light and gamma rays. While dark matter interacts with ordinary matter through gravity, it does not seem to interact at all with the electromagnetic spectrum, including visible light. So dark matter doesn't absorb, reflect, or emit any light.

While dark matter is invisible, it does have some things in common with ordinary matter: It takes up space and it holds mass. Because of this, we can see how it interacts with and influences ordinary matter throughout the universe, which is how we're able to "see" and study dark matter.

So, what can we see? And what have we seen that makes us so sure that dark matter exists?

Unlike normal matter, dark matter does not interact with the electromagnetic force. This means it does not absorb, reflect or emit light, making it extremely hard to spot. In fact, researchers have been able to infer the existence of dark matter only from the gravitational effect it seems to have on visible matter. Dark matter seems to outweigh visible matter roughly six to one, making up about 27% of the universe. Here’s a sobering fact: The matter we know and that makes up all stars and galaxies only accounts for 5% of the content of the universe! But what is dark matter? One idea is that it could contain “supersymmetric particles” – hypothesized particles that are partners to those already known in the Standard Model. Experiments at the Large Hadron Collider (LHC) may provide more direct clues about dark matter.

Dark energy makes up approximately 68% of the universe and appears to be associated with the vacuum in space. It is distributed evenly throughout the universe, not only in space but also in time – in other words, its effect is not diluted as the universe expands. The even distribution means that dark energy does not have any local gravitational effects, but rather a global effect on the universe as a whole. This leads to a repulsive force, which tends to accelerate the expansion of the universe. The rate of expansion and its acceleration can be measured by observations based on the Hubble law. These measurements, together with other scientific data, have confirmed the existence of dark energy and provide an estimate of just how much of this mysterious substance exists. Dark energy is basically the energy that is undetected – just the way how dark matter is undetected.

Many theories say the dark matter particles would be light enough to be produced at the LHC. If they were created at the LHC, they would escape through the detectors unnoticed. However, they would carry away energy and momentum, so physicists could infer their existence from the amount of energy and momentum “missing” after a collision. Dark matter candidates arise frequently in theories that suggest physics beyond the Standard Model, such as supersymmetry and extra dimensions. One theory suggests the existence of a “Hidden Valley”, a parallel world made of dark matter having very little in common with matter we know. If one of these theories proved to be true, it could help scientists gain a better understanding of the composition of our universe and, in particular, how galaxies hold together.

Dark matter is the invisible glue that holds the universe together. This mysterious material is all around us, making up most of the matter in the universe. But what exactly is dark matter? That's a question that scientists have been trying to solve for almost 100 years. Dark matter makes up most of the mass in galaxies and galaxy clusters. In fact, scientists estimate that ordinary matter makes up only about 5% of the universe, while dark matter makes up about 27%. (The rest is thought to be dark energy, which is its own mystery). It's thought that dark matter shapes the cosmos, organizing galaxies and cosmic objects on a large scale.

Energy from quantum level n = 3 of the void is currently creating the 4D (fourth spatial dimensional) part of our 3D Universe. Matter in the form of the three generations of elementary particles of the Standard Model is being sent from the point singularities of our Black Holes into the point singularities of the White Holes of 4D space where the fourth generation of elementary particles has been formed. The four generations are combined by 4D gravity to form 4D matter. During the construction of the final nth dimension, the Standard Model will be filled up with a table of n generations of columns and 4 rows of elementary particles. Matter of all the n dimensions is composed only of elementary particles of the first generation since elementary particles of all higher generations are heavier, hence unstable, and therefore decay into 1D elementary particles. While Dark Energy is the energy of photons located in different levels “n” of the void, Dark Matter is the 4D matter located in the 4D part of our 3D Universe made of protons, neutrons, electrons, and electron neutrinos. Bullet Cluster and Gravitational Lensing experiments confirm the existence of Dark Matter in the 4D part of our 3D Universe.

The scientists have gone even further in adding more mystery to the theory – they suggest that the Dark matter and the ordinary matter exactly coincide, meaning that there is the exact same universe somewhere around us, but we cannot sense or detect it! Just think, the same world, the same country, the same materials, the same constructions, the same everything, a complete parallel universe – just unseen and hidden from us due to mother nature’s love to make mysteries and make us suggest new theories (constantly changing present hypothesis). It seems very difficult to believe, right? You aren’t alone, my dear. Even we found it quite difficult to digest the facts presented, but I guess, we were proven wrong.

Scientists first began to suspect the presence of some unknown type of matter in the 1930s when observations suggested that galaxies in clusters behaved as though the gravity pulling them was stronger than could be accounted for by the amount of matter the scientists could see. Strong evidence for the existence of dark matter finally arrived in the mid-2000s in the form of the Bullet Cluster, shown here, which is actually two clusters of galaxies colliding with each other. Observations using a technique called gravitational lensing showed that most of the mass in the cluster was well-separated from the hotly glowing—and thus visible—clouds of gas (pink), demonstrating that the dark matter (blue) did not feel pressure from the normal matter.

Since the publication of Sir Isaac Newton’s cornerstone work Philosophiae Naturalis Principia Mathematica in 1687, science has struggled towards the explanation of the motion of astrophysical objects in terms of the laws of gravitation. Deviations of observed motions from expected trajectories have proved very effective in deepening the understanding of the Universe. Whenever anomalies were observed in the motion of planets in the solar system, the question arose: should such anomalies be regarded as a refutation of the laws of gravitation or as an indication of the existence of unseen objects, or in a much modern expression: ‘dark’ objects? This second approach proved to be exactly the case of the anomalous motion of Uranus, which led to the existence of Neptune, but failed to explain the anomalies in the motion of Mercury. The latter had to wait for the advent of Einstein’s theory of general relativity. The nature and identity of the dark matter (DM) of the Universe is one of the most challenging problems facing modern cosmology. The problem is a long-standing one, going back to early observations of mass-to-light ratios by Zwicky. This mysterious component that makes up about 22% of the Universe’s energy contents is conceptually very similar to the old problem of unseen planets. Observations of some ‘anomalies’ in large astrophysical systems, with sizes ranging from galactic to cosmological scales, can only be explained either by assuming the existence of a large amount of unseen, dark matter, or by assuming a deviation from the known laws of gravitation and the theory of general relativity.

The most direct and convincing evidence for DM comes at the galactic scale. The rotational curves of disk galaxies, namely the distribution of circular velocity of stars with respect to their distance from the centre of the galaxy, are obtained observationally. Usually, the resulting behaviour of a flat profile at large distances from the galactic centre does not match the theoretical prediction. One of the several methods to calculate the mass of a cluster is treating it as a hydrostatic system at equilibrium.

Roughly speaking, outside the core, the temperature of the cluster is constant and the density profile follows a power law with an index between –2 and –1.5. As early as 1933 Fritz Zwicky compared the mass-to-light ratio of the galaxies at the Coma cluster with the Solar neighbourhood. The considerable discrepancy in the resulting temperatures among that cluster and the Solar neighbourhood suggests the existence of a large amount of DM.

Back in 1964 Arno Penzias and Robert Wilson observed an isotropic radiation coming from space. This radiation, the CMB (Cosmic Microwave Background) had already been predicted by George Gamow and his collaborators in the 1940s. After the Big Bang, as the Universe cooled down, it went through different stages: first baryogenesis, then the primordial nucleosynthesis followed by neutrino decoupling, etc. Through those epochs the Universe experienced the decoupling of certain particles, that is, their interactions at some point stopped being fast enough compared to the expansion of the Universe; hence they stopped being in equilibrium with the plasma. Particularly important is the decoupling of photons. Those photons constitute the CMB observed nowadays, and as they have been travelling essentially free ever since, they are imprinted with the characteristics of the Universe at the moment of their decoupling, the last scattering surface.

There are some properties that a candidate for dark matter should have: it must be electrically neutral, massive, weakly interacting, and stable. None of the known particles from the Standard Model (SM) have these characteristics; therefore DM is a signature of new physics. Many theoretical models have proposed candidates for DM, among them: sterile neutrinos, light scalar fields, axions, particles from Little Higgs models, Kaluza– Klein states, superheavy dark matter, Q-balls, CHAMPs, heavy fourth generation neutrinos, and within supersymmetry (SUSY) models there are sneutrinos (ν˜), neutralinos (χ~01), gravitinos (g˜), and axinos. SUSY is a symmetry that relates bosonic with fermionic degrees of freedom. In practice it generates a new set of particles which are related to the particles we know (the SM particles), called the superpartners, which have half-spin difference from the SM ones.

One of the most promising techniques to detect dark matter is by direct detection experiments. These experiments are based on the idea that the galaxy is filled with WIMPs and a fraction of them pass through the Earth. Therefore, it is possible to look for the interaction of WIMPs with matter. To evaluate the rate of WIMP–nucleon scattering events, per unit of time and per unit detector material mass, we need to know the density, the velocity distribution and the WIMP–nucleon cross-section.

The Higgs and Dark Matter will be the two most searched for particles in the next few years. The gigantic experimental effort towards the discovery of the Higgs boson is all taking place at the Large Hadron Collider (LHC). Besides, there is a fervent activity in trying to identify the nature of the Dark Matter (DM) and in contrast with the search for the Higgs boson, this effort is spread on many different fronts, using three very different approaches. First, DM will be searched for at the LHC as missing energy events. However, even if we were to detect events at the LHC with large missing energy, we would not be able to conclusively say that we have discovered dark matter. It would only mean that we have produced a particle with at least a nanosecond lifetime. We will therefore need complementary information from direct detection experiments. Here, the idea is to search for recoil energy events in underground detectors. There are tens of such competing experiments all around the earth. Another flourishing activity is to search for DM indirectly, by looking for the products of annihilation or decay of DM, like positrons, electrons, photons, neutrinos, antiprotons...

Note that all these approaches assume that DM is a Weakly Interacting Massive Particle, which is a very compelling (but not unique) possibility. In contrast with DM, the Higgs is being searched solely at colliders, although the LHC and Tevatron are not the only places in the universe where the Higgs could be produced today. Indeed, it may be copiously produced in our galaxy in dark matter annihilations or decays. Nevertheless, being unstable, the only way to probe it outside of colliders is if the Higgs is being produced in association with a stable particle, which can be detected, such as a photona. The reason why this is interesting is that DM being non-relativistic today, the photon is monochromatic and its energy gives us information about the higgs and DM masses.

If the WIMP hypothesis is correct and if DM is connected to the dynamics of EW symmetry breaking, it is natural to expect the WIMP to have couplings which favor the most massive states of the Standard Model. Here, we explore the possibility that the WIMP has important couplings to the top quark, through which it can couple at the loop level both to photons and to Higgs bosons. In addition to being a solution to the little hierarchy problem, the Mirror Twin Higgs provides a natural setting for Asymmetric Dark Matter. In its incarnation with only one Higgs doublet and its mirror copy, dark matter would however almost certainly consist mostly of mirror atoms, which is severely ruled out by constraints on dark matter self-interactions. By adding a second Higgs doublet and its mirror, the vevs of the different Higgses can be arranged such that dark matter consists mostly of mirror neutrons, which is cosmologically viable. In this paper, it is shown that current constraints from colliders, flavour and cosmology can accommodate such a vev structure with little increase in the necessary tuning.

The presence of a non-baryonic Dark Matter (DM) component in the Universe has been inferred from the observation of its gravitational interaction. If Dark Matter interacts weakly with the Standard Model (SM) it could be produced at the Large Hadron Collider (LHC) experiments, escaping the detector and leaving a large missing transverse momentum as its signature. The LHC experiments have developed a broad search program for DM candidates, in signatures with large missing transverse momentum produced in association with other particles (including light and heavy quarks, Z and H bosons, as well as additional heavy scalar particles), direct resonance searches for mediator particles coupling dark matter to the SM, and searches for invisible Higgs decays as would result if the Higgs boson provides a direct portal to dark matter. Searches have also been made for extended or strongly-interacting dark sectors, that can result in long-lived or novel hadronic signatures. A review of recent collider DM searches on 13 TeV proton-proton data, their interplay and interpretations will be presented.

Supersymmetric Twin Higgs models ameliorate the fine-tuning of the electroweak scale originating from the heavy scalar top partners required by the non-discovery of them at the Large Hadron Collider. If the Lightest Supersymmetric Particle resides in the twin sector, it may play the role of dark matter even if it is charged under twin gauge interactions. We show that the twin stau is a viable candidate for charged dark matter, even if the twin electromagnetic gauge symmetry is unbroken, with thermal relic abundance that naturally matches the observed dark matter abundance. A wide parameter space satisfies all the experimental constraints including those on dark matter self-interactions. Twin stau dark matter can be observed in future direct detection experiments such as LUX-ZEPLIN. The stau has a mass in the range of 300- 500 GeV, and in the minimal scenario, has a decay length long enough to be observed as a disappearing track or a long-lived particle at the Large Hadron Collider.

Gravitational lensing is still our best tool for finding and studying dark matter. It uses Albert Einstein's prediction, now demonstrated thousands of times, that concentrations of matter can bend light. During gravitational lensing, rays from a far-distant source, such as a young galaxy, passes by a concentration of matter, such as another galaxy, that lies between the source and the Earth. This concentration of matter serves as a lens, bending the light toward us and magnifying the source.

Strong lensing, the best-known type of gravitational lensing, can actually create several recognizable images of the source, while weak lensing, a more subtle phenomenon, causes distortions in the appearance of the more distant objects. The two techniques in tandem can not only help us understand dark matter, but enable us to use the mysterious substance as a tool to track the growth and evolution of the Universe. But strong lenses are rare; weak lenses are more common but their effects are difficult to see without huge amounts of data about galaxy sizes and shapes to enable us to tell the true gravitational distortions from natural anomalies in shape. Finding enough gravitational lenses to constrain the properties of dark matter structures requires a powerful telescope with a huge field of view—like Rubin Observatory. Rubin Observatory will find thousands more gravitational lenses of all sizes and configurations, and what these lenses show us about themselves as well as the objects they magnify will expand our understanding of the Universe in both time and space.

Scientists looking for dark matter have looked almost everywhere they could imagine: deep underground detectors, powerful particle colliders, precision telescopes, and maps of the universe itself. Yet, despite making up most of the matter in the cosmic realm, dark matter remained frustratingly invisible.

Now, researchers think they may have found a profoundly different way to look for it: by listening to black holes collide. A new study published in Physical Review Letters suggests that gravitational waves—the tiny ripples in spacetime generated when black holes merge—may carry subtle fingerprints of dark matter if those black holes happen to collide within dense concentrations of the mysterious substance. “We know that dark matter is around us. It just has to be dense enough for us to see its effects,” co-author and MIT postdoc research fellow, Dr. Josu Aurrekoetxea, said in a press release. “Black holes provide a mechanism to enhance this density, which we can now search for by analysing the gravitational waves emitted when they merge.”

Dark matter is believed to account for roughly 85 percent of all matter in the universe, yet it has never been directly detected. Scientists infer its existence because galaxies rotate too quickly and large-scale cosmic structures behave as though far more mass exists than telescopes can see. Unlike ordinary matter, dark matter appears to interact almost exclusively through gravity, making it extraordinarily difficult to detect using conventional techniques.

That challenge motivated researchers to pose a different question. Instead of trying to see dark matter directly, could scientists detect its influence on something else?

The researchers’ answer focused on gravitational waves. These are disturbances in spacetime first directly detected in 2015 by the Laser Interferometer Gravitational-Wave Observatory (LIGO). Since then, the international LIGO–Virgo–KAGRA collaboration has catalogued dozens of black hole mergers and transformed gravitational-wave astronomy into one of the fastest-moving areas of astrophysics.

Traditionally, those signals have been treated as extraordinarily clean probes of the black holes themselves. However, in this recent study, researchers argue that the environment around merging black holes may matter more than previously thought.

The study centres on a class of hypothetical dark matter candidates called ultralight scalar particles. These represent exotic fields that appear naturally in many extensions of the Standard Model of particle physics and have long been considered viable dark matter candidates.

Under the right conditions, ultralight scalar particles could accumulate around spinning black holes, forming extremely dense clouds. Moreover, some of those clouds could become astonishingly concentrated.

The most recent study, published on July 8, explores whether dark matter could have formed in a hidden sector—a kind of “mirror world” with its own versions of particles and forces. While completely invisible to humans, this shadow sector would obey many of the same physical laws as the known universe.

The idea draws inspiration from quantum chromodynamics (QCD), the theory that describes how quarks are bound together inside protons and neutrons by the strong nuclear force. UC Santa Cruz has deep roots in this area: Emeritus physics professor Michael Dine helped pioneer theoretical models involving the QCD axion, a leading dark matter candidate, while research professor Abe Seiden contributed to major experimental efforts probing the structure of hadrons—particles made of quarks—in high-energy physics experiments.

In Profumo’s new work, the strong force is replicated in the dark sector as a confining “dark QCD” theory, with its own particles—dark quarks and dark gluons—binding together to form heavy composite particles known as dark baryons. Under certain conditions in the early universe, these dark baryons could become dense and massive enough to collapse under their own gravity into extremely small, stable black holes—or objects that behave much like black holes.

These black hole-like remnants would be just a few times heavier than the fundamental mass scale of quantum gravity—known as the ‘Planck mass”—but if produced in the right quantity, they could account for all the dark matter observed today. Because they would interact only through gravity, they would be completely invisible to particle detectors—yet their presence would shape the universe on the largest scales.

According to researchers, a process called superradiance may allow rapidly spinning black holes to transfer rotational energy into surrounding ultralight particles, dramatically amplifying them. In some scenarios, those dark matter structures could reach densities more than 30 orders of magnitude greater than the average dark matter density in our galaxy. If a pair of black holes then spiralled together inside one of these environments, the surrounding scalar field would slightly alter their orbital motion. That change would be subtle but measurable.

Rather than producing the gravitational-wave “chirp” expected from two black holes merging in empty space, the waves would show tiny distortions in timing and phase evolution, essentially arriving with an altered rhythm. To test the idea, researchers developed a new semi-analytic waveform model capable of predicting how black hole mergers should appear embedded within environments of scalar dark matter. They then validated those predictions using full numerical relativistic simulations that model black hole mergers inside dense scalar fields.

The simulations showed that dark matter-like scalar structures could survive the violent inspiral process better than many earlier models had suggested. Previous thinking often assumed equal-mass black hole binaries would destroy surrounding dark matter structures before merger. However, the new simulations suggest the opposite may sometimes occur. Portions of those structures can persist and potentially leave observable signatures in gravitational waves.

Environmental effects, parameter indeterminacies, or constraints in current waveform models could potentially mimic some of the observed behaviour. Researchers carefully examined possibilities, including orbital eccentricity and line-of-sight acceleration, and found no strong evidence that those effects explain the signal, but warn that confirmation will require future observations.

“The statistical significance of this is not high enough to claim a detection of dark matter, and further checks should be performed by independent groups,” Dr. Aurrekoetxea said. “What we think is important to highlight is that without waveform models like ours, we could be detecting black hole mergers in dark matter environments, but systematically classifying them as having occurred in vacuum.”

That said, further checks of the researcher’s theory may arrive sooner than expected.

Current gravitational-wave observatories continue collecting data, and next-generation instruments such as the Einstein Telescope and Cosmic Explorer are expected to detect mergers with far greater sensitivity and over longer durations. That improvement could make tiny environmental signatures easier to isolate from ordinary black hole physics.

For now, the result remains an intriguing hint, but not yet proof. Nevertheless, after decades of dark matter remaining elusive through light, particles, and laboratory experiments, researchers are beginning to explore the possibility that the universe’s missing mass may announce itself in an entirely different way. Not by being seen. But by changing the sound of spacetime itself.

More intriguingly, when researchers applied their method to real gravitational-wave observations, one previously recorded event appeared to show a tentative preference for exactly that kind of hidden environment. The results do not amount to a discovery of dark matter. Researchers repeatedly stress that alternative explanations are possible and that additional observations will be required. Still, the work opens a new observational front in one of modern physics’ longest-running mysteries.

Although only a few times heavier than the fundamental mass scale of quantum gravity, these dark black holes could potentially account for all of the dark matter inferred to exist—if they formed frequently enough. A compelling aspect of this idea is that it could explain why dark matter has remained undetected. These black holes would be invisible to particle detectors, yet their gravitational influence would be felt across the cosmos. Because they would interact solely through gravity, they would evade detection by conventional means. Yet their presence could still help shape the large-scale structure of the universe. By relying on established physics, it offers a testable hypothesis that doesn’t require introducing new particles beyond the Standard Model.

As discussed above, dark matter is undetectable by direct instruments, because it is electromagnetically neutral, it doesn’t emit, absorb or reflect light. This makes it invisible to telescopes. Dark matter takes up 27% of the entire universe, while dark energy takes up 68% of the universe. Ordinary matter, which is everything we can see, understand and touch, takes up only 5% of the whole universe. Scientists differentiate between dark matter and dark energy, as they behave differently. Dark matter seems to have mass and form giant clumps. Cosmologists calculate that the gravitational attraction of these clumps played a key role in causing ordinary matter to form galaxies and other clusters and superclusters. Dark energy, by contrast, appears to be without mass and spreads uniformly throughout space where it acts as a kind of anti-gravity, a repulsive force that is pushing the universe apart to create massive dark regions called voids. There are many theories and science fiction lores analysing the formation of these voids. It appears some mysterious force causes superclusters to run out of energy to form voids. Is it Dark energy that forces the energy out of the galaxies? If so, how?

We know that the Dark energy can also change its behaviour in a mysterious way to act like gravity, as explained above through the formation of these clusters and superclusters. Humans are fundamentally composed of normal matter and energy, we can feel it, touch it, use the energy, harvest this energy. Our body cells effectively use this kind of usable energy to function. Our evolution in Earth was stimulated through this matter and energy. But, normal matter and normal energy are not the only kinds of existent energy. Dark matter and Dark energy make up most of the universe. They could also result the existence of other intelligent entities, which can utilise this dark energy to go beyond their regions; they explore outside their realm, and they enter our solar system. Unfortunately, we haven’t yet utilised the full potential of normal energy, let alone using Dark Energy. Thus, it is very clear that those entities are a lot more advanced than us, and most probably, their morning walk in our solar system and planet Earth has led to some pretty unexplained occurrences.

Thus, we gave these potentially existing and very highly advanced beings a cool name: extraterrestrials. Dark energy is a deeply mysterious force that counteracts gravity and causes the universe to expand at an accelerating rate. It can change its behaviour in a very unpredictable way. It changes the unpredictable by actively altering the ultimate fate of the universe. Human perception is strictly locked into three dimensions; we are inherently blind to fourth dimension. In our three-dimensional reality, when a 3D object is placed in front of a light source casts a flat, two-dimensional shadow. What if Shadow people are a fourth dimensional entity, if it passes through our universe, or interacts with it, we won’t be able to perceive its true form. We might only see its three-dimensional shadow, which we describe as paranormal encounters. In the same way, other extraterrestrials, like aliens, could be a being from the 4th dimension. According to the Law of Conservation of Energy. Energy can neither be created or destroyed. It can only change from one form to another. This suggests extraterrestrials are able to change dark energy to normal energy. After this, they explore beyond Dark matter. They walk into our universe, our galaxy, and into our solar system, in their so-called, vehicles which are yet undetected. We call these vehicles unidentified flying objects (UFOs). They have much more advanced technology than us. They are able to go invisible, and they also might be interdimensional beings, since they could be four-dimensional beings, and they can move into our dimension in their 4D form, causing us to see some really weird and distorted visions sometimes (if we are really lucky to catch them in their act). The explanation is very simple: we are 3D, but we can access and distort 2D and 1D, and in the same way, these respected alien brothers and sisters can come and distort our reality, leading to some incredible scenarios.

You must have seen or heard a lot of events and research regarding aliens and extraterrestrial life. It is also suggested that extraterrestrials have methods and plans; in fact, their visits elsewhere might be a mission. Now, you might ask why we haven’t discovered any other civilisations. The reason is very simple.

This is mainly explained by the Fermi Paradox. This Paradox highlights a profound contradiction: if intelligent alien civilisations are common and expand across the galaxy within just tens of millions of years, then “where is everybody?” It is the contraction between high statistical probability that extraterrestrial life exists and the lack of physical evidence or contact with them. The conditions for intelligent life to arise don’t seem uncommon in the Cosmos, but we don’t observe anybody out there.
There are hundreds of billions of stars in the Milky Way galaxy, and many of those are similar to the Sun, they have Earth-like planets in their habitable zones, such as Kepler-186f, Kepler-452b, Proxima Centauri b, and TRAPPIST-1e. Many of these worlds have likely hosted habitable conditions for as long as Earth has, or even longer. So, it is very likely that the earth has developed life by now. It could be mind-blowingly extraordinary if Earth were the only planet in the galaxy to have done so. Their stars are billions of years older than ours, so it is highly likely that they are more technologically experienced, and they are capable of interstellar travel, or communication. This leads to the conclusion that detectable alien civilizations should be common in our galaxy, it stands to reason that the universe should be buzzing with activity, but we have been searching for signals for decades, but haven’t heard anything. This absence of signals, spacecraft, or any other signs of alien intelligence is sometimes called the “Great Silence.”

The Theories mentioned below are collectively known as explanations for the Fermi Paradox.

The Different Kind of Life hypothesis: This is a theoretical framework suggesting that extraterrestrial life may exist in forms, biochemistries, and states of matter are fundamentally different from anything found on Earth.

Eath-based life is constructed around carbon chains and requires liquid water as a solvent. Astrobiologists hypothesize that life in other environments could utilize entirely different chemistries. They could have a Silicon-based life! Sounds funny right? The same stuff that makes computer chips and electrical circuits may also constitute life somewhere in the whole wide universe! Carbon can form bonds with up to four other atoms at once, bind to oxygen, and form polymer chains, all of it makes it ideal for the complex chemistry of life. Silicon is also below carbon in the periodic table; they also share these characteristics. However, silicon is still quite limited as a basis of life, it can only form stable bonds with a limited number of other elements. Its polymers would be very monotonous, limiting its ability to form the complex compounds needed for life to occur. Silicon chemistry is not stable in aqueous or watery environments. When silicon oxidizes, it forms silicon dioxide, also known as silica, quartz, or sand. This solid waste would pose some serious mechanical challenges for any silicon-based life. This hypothetical life form would excrete sand every time it took a breath. This is quite funny! Vacationing at the beach would have been horrifying.

However, silicon-based life would be more favourable for life than carbon-based. Silicon chemistry would be much more amenable to life in oceans of cold elements that we don’t usually associate with life, such as liquid methane, ethane, neon and argon. For example, Saturn’s largest natural satellite, Titan, has lakes of liquid ethane and methane. These compounds

Jupiter’s largest satellite, Ganymede, along with its sibling Europa, are considered the best for alien life. Europa’s orbital path around Jupitar lies deep within this powerful magnetic field, so it receives a continuous barrage of electrified particles or ions. According to a Researcher, Chyba, when these ions slam into the icy surface of the satellites, chemical reactions are likely to occur, transforming frozen molecules of water and carbon dioxide into new organic compounds such as formaldehyde. One of the most common bacteria on Earth, Hyphomicrobium, a gram-negative bacterium, survives on formaldehyde as its sole source of carbon. Chyba believes that similar formaldehyde-feeding microbes could be alive and swimming in Europe’s subsurface ocean. Radiation from Jupiter also may drive chemical reactions that produce oxidants, which are molecules such as oxygen and hydrogen peroxide that can be used to burn formaldehyde and other carbon-based fuels. Along with this, there is also the existence of frozen ice caps in these two natural satellites that Jupiter possesses. This ice when melted forms water which could support life in various ways. Including the habitable conditions that these two satellites contain, it is very possible that these two satellites could possibly support life, and they also could contain forms of life that we are yet unaware of.

The Far Away Hypothesis: This is a proposed solution to the Fermi Paradox. It suggests that extraterrestrial civilizations are out there, but the cosmos is simply too vast and distances between them are too big for us to have detected their signals or to interact with. The observable universe is about 93 billion light-years and contains billions of galaxies. An alien signal must travel such a large vacuum just to reach us. Electromagnetic signals, such as radio waves and light can only travel at the speed of light, which is approximately 299,792,458 meters per second. Even this speed is really slow when compared to the vast distance between interstellar objects. The distance between Earth and the second nearest star, Proxima Centauri, is approximately 4.25 light years. This means that the light takes 4 years to reach us, and that the image of Proxima Centauri that we see now is around 4 years and 3 months old! We see how Proxima Centauri was a little more than 4 years ago! One light year is about 94,60,730,472,580 km. It is the distance covered by light in a whole earth year. Also, the distance between our Milky Way and Andromeda galaxy is around 2.5 million light years. The image we see of Andromeda galaxy is thus 2.5 million years old! Thus, it takes millions of years for signals to cross the interstellar void. This can also be explained by the brief window hypothesis. In the classical Drake Equation, L is defined as the length of time a civilization takes to develop the necessary technology and transmit a signal. The brief window hypothesis also considers the time it would take to get a reply. Civilizations may only possess the technology to broadcast signals or travel the stars for a very brief period before they collapse or destroy themselves.

The Zoo hypothesis: This hypothesis is the least unsettling in the fermi paradox. This hypothesis holds that they can see us, but we cannot see them. Aliens may not find us humans as worthy as them. In fact they might consider us as uncivilised beings, and keep us in a universal display, much like we do to animals in a zoo. We are flawed beings. We threaten each other, cause harm to one another. Humans have little to no respect for each other. Many of us spread false rumours and accusations about one another. Perhaps the extraterrestrials know we’re here, but they don’t want to deal with us. This hypothesis was first discovered by MIT Astronomer John Ball, he argued that highly technologically advanced aliens might already exist, but their scientists decided to a hands-off policy. Human beings are effectively in a cosmic zoo being observed by more advanced aliens. Humans are animals, and the aliens are the ambassadors who are monitoring our development! Sounds quite funny, this hypothesis has been a popular topic for many science fiction writers. Some versions of the theory suggest that interacting with a technologically society could destabilize humanity. The other Intelligent life in the universe decided to leave us alone and allow us to evolve naturally. This is their “Prime Directive” it upholds the principle that the extraterrestrials must refrain from contacting a species way too early in their development or interfering with it.

Now, with so many possibilities and theories for unknown, undiscovered life somewhere else in the universe, and also the possibility that there are other civilised creatures in the universe. Maybe some of you have heard about the term ‘Shadow people’. If you haven’t, we would recommend some of the references below (search and find out yourself), or, better, see the article, ‘Are We Alone’ given in this website. For a head start, shadow people are jet-black silhouettes that move amongst us. They are most likely beings from the realm of dark matter. They could be interdimensional, which means that they could be from the 4th dimension. As discussed above, humans' perception is locked to 3 dimensions only, so if a shadow person, who is probably from the 4th dimension interacts with out 3-dimensional reality, we might just see it’s just a shadow or an unsettling presence. The interesting fact is that, since these are from the ‘dark’ dimension (from dark matter and dark energy of course), these might actually be invisible to the naked eye until or unless they are willing to show themselves. Many of the times, we sometimes feel like we are being watched, something out of order, lights flickering, unsettling feelings and occurrences. We just brush it off as hallucination and as a result of tiredness, or, we just think that the brain tricks us and put forward a psychological explanation (do you honestly believe these nonsense explanations which require a translator just to understand?) People with schizophrenia tend to have such hallucinations.

People brush it off as a trick of their mind. However, the very real possibility of mysterious beings from dark matter existing may be proved through everyday paranormal incidents. Many people have many strange experiences which just cannot be an illusion, for the fact that there has been physical interactions with these shadow people. Some people are reported to have been thrashed off trees in many regions in Bangladesh (especially tamarind trees), knocked fully unconscious, and after they regained consciousness, they report that a dark, mysterious, haunting translucent black, almost smoky humanoid figure, often possessing an eerie apparition and a pair of glowing eyes, apparently grab their hands and then push them off with incredible force. Now, for only one or two people, it could just be a simple hallucination, but far more people have reported similar events, each description having strikingly similar details.

Now, whether or not these are just a part of a huge hoax, or just truly paranormal unsettling events, you decide. But, we advise that whenever you feel that something is off, you also consider the very faintest possibility, just because there is a mirror, an entire universe beyond our comprehension that we just cannot see.

References:

https://arxiv.org/abs/2007.00052

https://cds.cern.ch/record/1114397/files/p297.pdf

https://cds.cern.ch/record/2861081/files/astronomy-02-00007v2.pdf

https://cds.cern.ch/record/2765259/plots

https://cds.cern.ch/record/2274362/files/1269358_445-450.pdf

https://cds.cern.ch/record/2843045

https://cds.cern.ch/record/2843045/files/ATL-PHYS-SLIDE-2022-630.pdf

https://cds.cern.ch/record/2803902/files/2202.10488.pdf

https://cds.cern.ch/record/2803902

https://cds.cern.ch/record/2826795/files/ATL-PHYS-SLIDE-2022-460.pdf

https://home.cern/science/physics/dark-matter/