# Hubble’s Law
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Who / What
Hubble’s law is an observation in physical cosmology that describes the expansion of the universe. It posits that galaxies are moving away from one another at speeds proportional to their distance, with more distant galaxies receding faster.
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Background & History
Hubble’s law was formulated based on observations made by astronomer Edwin Hubble in the early 20th century. Initially, he noticed a correlation between the velocity of spiral nebulae (later identified as distant galaxies) and their distances from Earth. This discovery was further refined by Georges Lemaître in the 1920s, who proposed that the universe is expanding uniformly. The law became foundational to modern cosmology after Hubble’s work confirmed the existence of other galaxies beyond the Milky Way.
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Why Notable
Hubble’s law revolutionized our understanding of the universe by providing empirical evidence for its expansion. It underpins key theories in cosmology, including the Big Bang theory, and has been instrumental in mapping the large-scale structure of the cosmos. The discovery also led to advancements in observational astronomy, enabling scientists to measure cosmic distances and velocities with greater precision.
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In the News
Hubble’s law remains a cornerstone of modern astrophysics, continually informing research on dark energy, galaxy formation, and the universe’s expansion rate (the Hubble constant). Recent studies using data from telescopes like the James Webb Space Telescope rely on this principle to refine cosmological models and explore distant galaxies. Its relevance endures as a fundamental tool in unraveling the mysteries of the cosmos.
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Key Facts
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