The universe's size is unknown, and it may be infinite in extent. Some parts of the universe are too far away for the light emitted since the Big Bang to have had enough time to reach Earth or space-based instruments, … See more

Number of galaxies and stars
The observable universe contains as many as an estimated 2 trillion galaxies and, overall, as many … See more

The most distant astronomical object identified (as of August of 2024) is a galaxy classified as JADES-GS-z14-0. In 2009, a gamma ray burst, GRB 090423, was found to have a redshift of 8.2, which indicates that the collapsing star that caused it exploded … See more

Both popular and professional research articles in cosmology often use the term "universe" to mean "observable universe". This can be justified on the grounds that we can never know anything by direct observation about any part of the universe that is See more

The comoving distance from Earth to the edge of the observable universe is about 14.26 gigaparsecs (46.5 billion light-years or 4.40×10 m) in any direction. The observable universe … See more

Sky surveys and mappings of the various wavelength bands of electromagnetic radiation (in particular 21-cm emission) have yielded much … See more

• Bolshoi cosmological simulation – Computer simulation of the universe
• Causality (physics) – Physics of the cause–effect relation
• Chronology of the universe – History and future of the universe See more