Dark Matter and Dark Energy
Since the dawn of modern astronomy, humanity has been enthralled by the mysteries of our universe, with each discovery adding new dimensions to our cosmic understanding. Among these stand two enigmatic forces: dark matter and dark energy.
In 1933, astrophysicists stumbled upon the puzzling fact that the visible mass of the galaxies alone is insufficient for their gravitational cohesion—something else must be producing the additional force. This idea is the origin story of dark matter, constituting about 27% of our universe. Dark matter exhibits no known interactions with visible matter or electromagnetic waves but occupies space and exerts gravity, like mass. Its presence has been inferred through fluctuations in the Cosmic Background Radiation and gravitational lensing. While its true nature remains uncertain, we know it’s not antimatter or black holes. Potential candidates for dark matter include MACHOs and WIMPs.
Dark energy, comprising approximately 68% of the universe, has the opposite effect of dark matter: it fuels the expansion of the ever-accelerating universe and creates space between matter. This concept originated in the 1920s when astrophysicists observed galaxies moving further apart. Unlike matter, dark energy seems to uniformly permeate space and time. Scientists theorize that dark energy may be generated through quantum fluctuations in “empty” space. Interestingly, the properties of dark energy align with Einstein’s Cosmological Constant (Λ).
Despite no concrete proof of their existence, dark matter and energy are pivotal to modern physics. Either we can come closer to unraveling our universe’s past, present, and future, or we might have to revisit our knowledge of gravity and spacetime—perhaps they work differently for galaxies. Nevertheless, the allure of these unknowns continues to push the frontiers of science and technology, propelling us to uncover their complexities and mysteries.
