Topic summary
Universe

Everything in space and time UniverseThe Hubble Ultra-Deep Field image shows some of the most remote galaxies visible to present technology (diagonal is ~1/10 apparent Moon diameter)Age13.787 ± 0.020 billion yearsObservable diameter8.8×1026 m (28.5 Gpc or 93 Gly)Average density (with energy)9.9×10−27 kg/m3Average temperature2.72548 K(−270.4 °C, −454.8 °F)Main contentsOrdinary (baryonic) matter (4.9%)Dark matter (26.8%)Dark energy (68.3%)ShapeFlat with 0.4% error margin Part of a series onPhysical cosmology Big BangUniverse Age of the universe Chronology of the universe Early universe InflationBaryogenesisNucleosynthesis Backgrounds Gravitational wave (GWB) Microwave (CMB)Neutrino (CNB) Expansion and future Hubble's lawRedshift Expansion of the universe FLRW metricFriedmann equations Lambda-CDM model Future of an expanding universe Ultimate fate of the universe Components and structure Components Dark energyDark matter PhotonsBaryons Structure Shape of the universe Galaxy filamentGalaxy formation Large quasar group Large-scale structure ReionizationStructure formation Experiments Black Hole Initiative (BHI) BOOMERanG Cosmic Background Explorer (COBE) Dark Energy Survey Pl