univerzum

In Hungarian, the term univerzum corresponds to the English word universe and denotes the totality of space and time and all contents within them, including all matter and energy, galaxies, stars, planets, and the physical laws that govern them. In cosmology, the concept often refers to the observable universe, the portion we can study directly, though the actual universe may extend beyond.

According to the Big Bang model and general relativity, the universe is about 13.8 billion years old and has been expanding since its hot, dense origin. The cosmic microwave background provides a snapshot of the early universe, while the observed redshifts of distant galaxies reveal ongoing expansion, which is currently accelerating due to dark energy.

Normal (baryonic) matter makes up a small fraction of the total energy content; dark matter and dark energy constitute the rest. On large scales, matter forms a cosmic web of galaxies, clusters, filaments, and voids. The cosmological principle states that the universe is, on average, homogeneous and isotropic when viewed at sufficient scales.

Evidence for the universe's evolution comes from diverse observations, including galaxy surveys, primordial element abundances, and the cosmic microwave background. Open questions remain about the nature of dark matter and dark energy, the exact geometry of space, and the ultimate fate of the cosmos, with scenarios ranging from continued expansion to possible future changes in rate.