SPACERIUM

  The Cosmic Expansion The universe is undergoing a large-scale expansion. This is evident in the redshift of distant galaxies, indicating they are moving away from us at a rate proportional to their distance. This phenomenon, described by Hubble's Law, suggests the universe is stretching like an inflating balloon. However, it’s crucial to understand that this expansion occurs at the level of galaxy clusters and superclusters, not within individual galaxies or their groups. Gravity counteracts this expansion on smaller scales. Galaxy clusters, bound together by the mutual gravitational attraction of their member galaxies, form relatively stable structures. The motion of galaxies within these clusters is primarily influenced by their gravitational interactions, not the overall cosmic expansion. Dark Matter: The Invisible Architect Dark matter, a mysterious substance detectable only through its gravitational influence, plays a pivotal role in cosmic structure. This non-baryonic matte...

  Dark Energy In the late 1990s, astronomers found evidence that the expansion of the universe was not slowing down due to gravity as expected. Instead, the expansion speed was increasing. Something had to be powering this accelerating universe and, in part due to its unknown nature, this “something” was called dark energy. What Is Dark Energy? In the late 1990s, astronomers found evidence that the expansion of the universe was not slowing down due to gravity as expected. Instead, the expansion speed was increasing. Something had to be powering this accelerating universe and, in part due to its unknown nature, this “something” was called dark energy. Hubble plays an important role in verifying, characterizing and constraining dark energy. Both Hubble and ground-based observations measures a special type of stellar explosion, a white dwarf supernova, to measure accurate distances to galaxies.  ​ A galaxy located a billion light-years away provides a data point for the universe ...