Universe

The universe is all of space and time and their contents, including planets, stars, galaxies, and all other forms of matter and energy. The Big Bang theory is the prevailing cosmological description of the development of the universe. According to this theory, space and time emerged together 13.787±0.020 billion years ago, and the universe has been expanding ever since the Big Bang. While the spatial size of the entire universe is unknown, it is possible to measure the size of the observable universe, which is approximately 93 billion light-years in diameter at the present day. Some of the earliest cosmological models of the universe were developed by ancient Greek and Indian philosophers and were geocentric, placing Earth at the center. Over the centuries, more precise astronomical observations led Nicolaus Copernicus to develop the heliocentric model with the Sun at the center of the Solar System.

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Observing the Dark Ages of the Universe from the Far Side of the Moon

Machine Learning is Surprisingly Good at Simulating the Universe

'Time machine' reveals hidden structures in the universe's first galaxies (images)

NASA Telescope Snaps First Images of Universe After Vandenberg Launch

Universe Will Start to Shrink in Just 7 Billion Years, Claims Study

At 1.3 Billion Light-Years Wide, Quipu Is Officially The Biggest Thing in Our Universe

Nearly half of the universe’s ordinary matter was uncharted, until now

Physicists Unlock New Path to Weighing the Universe’s “Ghost Particle”

Rubin Observatory Data Flood Will Let the Universe Alert Astronomers 10 Million Times a Night

Astronomers Find Universe’s “Missing” Matter

Astronomers discover a galaxy frozen in time for billions of years: 'Fossil galaxies are like the dinosaurs of the universe'

Growing evidence for evolving dark energy could inspire a new model of the Universe

Record-breaking 10-billion-year radio halo just rewrote the universe’s origin story

A Physicist Explains The Explosive Birth of The Universe's Building Blocks

World’s largest camera just snapped the Universe in 3,200 megapixels

Cosmic Mystery Solved: Astronomers Have Discovered the Universe’s “Missing” Matter

The largest map of the universe reveals over 800,000 galaxies

Fast Radio Bursts are Helping to Locate the Universe's Missing Matter

Radio signals from the dawn of time could help 'weigh' the universe's 1st stars

Did our cosmos begin inside a black hole in another universe? New study questions Big Bang theory