The universe contains many phenomena, from minor to significant, hot to scary, and visible to invisible. However, everything we see only makes up 5% of what should exist for the universe to function correctly. The remaining 95% comprises dark matter and energy, which are elusive and challenging to study. Dark matter is invisible to us as it does not emit light and is thus difficult to detect. Scientists first discovered dark matter when they realized that galaxies were spinning too fast, suggesting that there was more mass present in the outer parts of galaxies than visible matter could explain. Weakly interacting massive particles (WIMPs), axions, sterile neutrinos, and dark photons are some leading candidates for dark matter. Scientists have attempted to detect these particles through various experiments, but conclusive results have yet to be obtained.
Dark energy is responsible for accelerated cosmic expansion, and without it, the universe would have collapsed into a big crunch. Dark energy permeates the fabric of space-time as a field or a type of particle. Emergent gravity is an alternative theory suggesting that gravity arises from quantum entanglement, which could explain the effects on galaxies and cosmic structures attributed to dark matter. However, there are no experimental observations to support this theory.
The search for dark matter and energy continues, and new experiments are being developed to detect these elusive phenomena. These cosmic mysteries continue to fascinate and challenge scientists, and discovering their properties could provide valuable insights into the universe’s workings beyond what we can currently see.