The expansion of the universe was discovered by separate theoretical and observational work in the 1920s. Since then, the expansion has become a core aspect of the astrophysical field of …

expanding universe, dynamic state of the extragalactic realm, the discovery of which transformed 20th-century cosmology.

Dec 13, 2024 · Then, in 1998, scientists discovered the universe’s rate of expansion is accelerating. In the years since, researchers using the Hubble Space Telescope have …

May 2, 2025 · Some 13.8 billion years ago, the universe began with a rapid expansion we call the big bang. After this initial expansion, which lasted a fraction of a second, gravity started to slow …

Aug 26, 2025 · If the universe is expanding now, will it continue forever, or will it slow and reverse under the pull of gravity? The answer depends on two opposing forces: the attractive pull of …

Oct 13, 2025 · If the universe is expanding, then what is it expanding into, and what is it expanding from? Where's the edge of the universe, and where is its center?

Dec 18, 2024 · Initiated by the Big Bang, this expansion is accelerating due to dark energy, which comprises most of the universe’s total energy. The complexities of expansion challenge both …

Dec 9, 2024 · New observations from the James Webb Space Telescope suggest that a new feature in the universe -- not a flaw in telescope measurements -- may be behind the decade …

Observations show that the expansion of the universe is accelerating, such that the velocity at which a distant galaxy recedes from the observer is continuously increasing with time. [1][2][3] …

May 4, 2025 · To answer those questions, we need to trace the story of the expanding universe—from ancient stargazers to modern-day telescopes probing the edges of time itself.