Because dark matter remains invisible to our current telescopes and detectors, despite its significant influence on the observable universe.
The enigma of dark matter continues to captivate the scientific community, as researchers strive to understand its elusive properties and behaviour. Several theories have emerged, each offering insights into the nature of this invisible substance that makes up a significant portion of the universe.
### 1. WIMPs (Weakly Interacting Massive Particles)
One of the leading candidates for dark matter is WIMPs, particles that interact with normal matter only through the weak nuclear force and gravity. Despite being a leading contender, direct detection of WIMPs has proven elusive, leading scientists to investigate alternative theories.
### 2. Axions
Another intriguing possibility is axions, hypothetical particles that could potentially explain dark matter. Predicted by some theories beyond the Standard Model, researchers are exploring innovative methods to detect axions, such as using magnetically levitated particles to measure subtle oscillations caused by dark matter moving through the Earth.
### 3. 5-plet and String Theory
The discovery of a 5-plet, a set of particles predicted by some theories, could challenge string theory while providing insights into dark matter if one of these particles is neutral and stable. Researchers are analyzing data from the Large Hadron Collider (LHC) to search for signs of the 5-plet, which could weigh around 10 TeV, fitting theories about dark matter's formation.
### 4. Fifth Force of Nature
Some theories propose a new, fifth force of nature beyond the known forces of gravity, electromagnetism, and the strong and weak nuclear forces. This force could be mediated by a particle that interacts with dark matter, and scientists are using trapped ions in experiments to search for signs of this undiscovered particle.
### 5. Simulations and Galaxy Observations
Simulations of galaxy formation and behaviour can provide invaluable insights into how dark matter interacts with normal matter and shapes galaxy structures. Researchers are creating supercomputer simulations of galaxy twins to compare with real observations, aiming to understand dark matter's role in galaxy formation and evolution.
The search for dark matter extends beyond the MACHOs versus WIMPs debate, with the possibility of abundant black holes in the outer reaches of galaxies being proposed. Only by determining which type of particle is responsible can we explain why dark matter has been so hard to find.
The evidence for dark matter includes gravitational lensing, where galaxies bend light from more distant objects more than visible stars can account for. Dark matter is estimated to be more than five times as abundant as visible matter in the universe, and its existence is inferred from the observed rates of objects orbiting each other, as the mass controlling orbital speed is often greater than what can be accounted for by visible matter alone.
However, contrary to MACHOs, WIMPs cannot be seen with existing instruments due to their lightness. The challenges in explaining the origin of these black holes have limited their popularity as a dark matter candidate.
The quest to identify the nature of dark matter continues, with ongoing research exploring these theories and testing their predictions through innovative experiments and simulations. The elusive nature of dark matter promises to keep scientists intrigued for years to come.
Science's exploration of dark matter delves into various realms, including space-and-astronomy and technology. The study of WIMPs, weakly interacting massive particles that could be a leading dark matter candidate, is enabled by advanced technology in particle physics. Similarly, the hunt for axions, another hypothetical particle that could explain dark matter, relies on cutting-edge technology like magnetically levitated particles. Furthermore, in the realm of medical-conditions, understanding dark matter's properties could potentially lead to breakthroughs in our comprehension of fundamental forces, as string theory and theories proposing a fifth force of nature are intertwined with this enigma.
