Introduction
The universe is so big, that it is created by an unprecedented event. We can see stars, planets, and galaxies using telescopes, but a very large substance is hidden in the shadows of the cosmos, and silently shaping it. This substance, called dark matter, is the greatest mystery in today’s astronomy. Unlike usual matter, dark matter can not emit or absorb light, rather it renders it invisible and can not be detected through conventional ways. It forms 27% of total cosmic mass and energy. On the other hand, ordinary one makes up only 5% (Ade, Aumont et al. 2016). The gravitational influence of dark matter is significant in terms of galaxy creation and the broader universe structure (Bullock and Boylan-Kolchin 2017). For the first time, hints of the existence of dark matter emerged from the observation of Fritz Zwicky in the 1930s, where he recognized that galaxies in the form of clusters moved very swiftly to be held by the visible matter solely (Zwicky 1979).
1. Understanding Dark Matter
Dark matter is a basic yet unknown portion of the universe that has attained the attention of astronomers and physicists for years. Ordinary matter builds up stars, planets, and all visible objects, while dark matter is not associated with electromagnetic forces, which means it can not emit, absorb, or reflect light. This property causes dark matter to be invisible, and its presence can only be detected by the gravitational effects it pulls on visible matter, radiation, and the universe’s structure (Bertone and Hooper 2018).
The dark matter’s existence was first presented to explain inconsistencies in the galaxy mass and clusters observed in comparison to the mass that is calculated based on visible matter only. Such inconsistencies were first identified by Fritz Zwicky where it was noted that the Coma Cluster galaxies were moving at an enormous pace which could not be described by the the visible matter’s gravitational pull only (Zwicky 1979). This resulted in the hypothesis that a hidden existence of matter, later came to be known as “dark matter,” must be pulling additional gravitational force to keep these galaxies held in one entity.
2. Dark Matter’s Role in Cosmic Structure
Dark matter has a vital role in shaping the broader cosmic structure. The dark matter’s gravitational impact is the primary power which drives the creation and evolution of structures of the cosmos (Bullock and Boylan-Kolchin 2017).
One of the strong parts of evidence for the dark matter’s role in the formation of the structure of the cosmos emerges from the research of the radiation of cosmic microwave background (CMB). The CMB is the afterglow of the Big Bang, giving a universe image when it was aged 380,000 years. Small CMB fluctuations, representing tiny variations of density in the starting universe, were the basis of all the structure creation. Such fluctuations would not have turned into the galaxies and clusters observed today if the additional pull of gravity given by dark matter was not involved (Ade, Aumont et al. 2016).
As the universe extended and cooled, dark matter started to accumulate together having its gravity, creating solid and highly dense areas called dark matter halos. The halos acted as the gravitational wells into which normal matter dropped, consequently making galaxies. If there was no dark matter, such structures would not have gotten enough pull of gravity for overcoming the extension and coalesce of the universe in the galaxy forms and galaxy clusters we see this day (van den Bosch, More et al. 2013).
3. Dark Matter and the Evolution of the Universe
The universe continues to evolve, since the day it was formed, and dark matter plays a pivotal role in it. After the Big Bang, the temperature of the universe was high with a dense soup of substances. The moment it extended and cooled, dark matter started to pull its gravitational effect, resulting in the creation of the primary cosmos structures. The radiation hindered the ordinary matter, on the other hand, dark matter freely clumped together in the earlier stages, making the wells of gravity that would consequently turn into galaxies and the clusters of galaxies (van den Bosch, More et al. 2013).
The impact of dark matter went on with the evolution of the universe. In the times of the “cosmic dark ages,” the time before stars and galaxies had been created, the gravitational pull of dark matter assisted in gathering the gas that would consequently light and create the first stars. These stars started to re-ionize the universe, putting an end to the dark ages and letting light letting for travelling with no intervention throughout space (Barkana and Loeb 2001).
4. The Search for Dark Matter
The exploration of dark matter is a significant challenge in today’s astrophysics and particle physics. The existence of dark matter is accepted worldwide because of its gravitational influences on ordinary matter, radiation, and the universe matter, dark matter has always remained mysterious. Scientists are searching for different tactics for the detection and comprehend this intriguing element of the universe.
One of the basic procedures for the detection of dark matter undergoes experiments of direct detection. Such experiments are made for the identification of uncommon interactions that form between the particles of dark matter and ordinary matter. Detectors are specifically put deep underground to save them from the rays of the cosmos and other noise generated by the background. There is the sensitivity of such experiments, like the experiment of Large Underground Xenon (LUX), hence no conclusive fact for dark matter is found yet (Brás, Lindote et al. 2017).
Another strategy is the detection which is done indirectly, which observes the dark matter decay products. Particles of dark matter, if exist, could clash with each other, generating gamma radiations, neutrinos, or other substances that are detected. Observatories such as the Fermi Gamma-ray Space Telescope have been exploring for such signals, but the consequences are not conclusive (Ackermann, Ajello et al. 2015). Scientists are trying to generate the particles of dark matter within particle accelerators, like the Large Hadron Collider (LHC) at CERN. By hitting protons together having alleviated energies, physicists aim to make situations somewhat similar to those post the Big Bang, where dark matter particles could be generated. Although the LHC has explored the Higgs boson, a big triumph, it has still to give evidence for dark matter (Boveia and Doglioni 2018).
Conclusion
Dark matter will remain the most mysterious aspect of today’s cosmology and particle physics. Although the dark matter presence is aided by various astronomical observations and gravitational influences, its accurate nature goes on to avoid detection. From the significant role it plays in the creation and evolution of the universe to its impact on the galaxies and clusters network, dark matter forms the universe in manners that are basic yet unseen.
References
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- Barkana, R. and A. Loeb (2001). “In the beginning: the first sources of light and the reionization of the universe.” Physics reports 349(2): 125-238.
- Bertone, G. and D. Hooper (2018). “History of dark matter.” Reviews of Modern Physics 90(4): 045002.
- Boveia, A. and C. Doglioni (2018). “Dark matter searches at colliders.” Annual Review of Nuclear and Particle Science 68(1): 429-459.
- Brás, P., et al. (2017). “Results from a search for dark matter in the complete LUX exposure.”
- Bullock, J. S. and M. Boylan-Kolchin (2017). “Small-scale challenges to the Λ CDM paradigm.” Annual Review of Astronomy and Astrophysics 55(1): 343-387.
- van den Bosch, F. C., et al. (2013). “Cosmological constraints from a combination of galaxy clustering and lensing–I. Theoretical framework.” Monthly Notices of the Royal Astronomical Society 430(2): 725-746.
- Zwicky, F. (1979). On the Masses of Nebulae and of Clusters of Nebulae. A Source Book in Astronomy and Astrophysics, 1900–1975, Harvard University Press: 729-737.
Mir Muhammad Adil
4th-year BS Biotechnology student at SZABIST University, Karachi
About the author: Mir Muhammad Adil is a passionate 4th-year BS Biotechnology student at SZABIST University, Karachi. With a strong interest in research, he is currently working on his final year project in biotechnology. Adil is also an experienced content writer and researcher, with multiple publications in books, magazines, and newspapers. In addition to his academic and research pursuits, he is a multilingual poet and writer, creating work in English, Urdu, and Sindhi. Adil’s dedication to both science and literature reflects his diverse skills and commitment to making meaningful contributions in both fields.
