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General relativity

General relativity (GR) is the geometrical theory of gravitation published by Albert Einstein in 1915. It unifies special relativity and Sir Isaac Newton's law of universal gravitation with the insight that gravitation is not due to a force but rather is a manifestation of curved space and time, with this curvature being produced by the mass-energy and momentum content of the spacetime. General relativity is distinguished from other metric theories of gravitation by its use of the Einstein field equations to relate spacetime content and spacetime curvature.

General relativity is currently the most successful gravitational theory, being almost universally accepted and well confirmed by observations. The first success of general relativity was in explaining the anomalous perihelion precession of Mercury. Then in 1919, Sir Arthur Eddington announced that observations of stars near the eclipsed Sun confirmed general relativity's prediction that massive objects bend light. Since then, many other observations and experiments have confirmed many of the predictions of general relativity, including gravitational time dilation, the gravitational redshift of light, signal delay, and gravitational radiation. In addition, numerous observations are interpreted as confirming the weirdest prediction of general relativity, the existence of black holes.

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October 6, 2026
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A Meteor Hit Oklahoma 100 Million Years Later Than Scientists Thought
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Powerful Simulations Reveal How the First Stars Changed the Universe
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This Suitcase-sized Spacecraft Could Hear the Universe Before Stars Existed
Sep. 28, 2026 — CosmoCube will use the far side of the Moon as a shield from Earth’s radio noise to search for a faint signal from the universe before the first stars existed. The suitcase-sized satellite could reveal how the cosmic dark ages ended and how dark ...
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The Secret to Growing Food on Mars Could Be Fungi
Sep. 25, 2026 — Scientists think beneficial fungi could help transform nutrient-poor lunar and Martian regolith into a material capable of supporting crops. By helping plants access nutrients and withstand harsh conditions, these microbes could someday make ...
A Strange Circle on Satellite Maps Turned Out to Be a 390-million-year-old Impact Crater
Sep. 22, 2026 — An amateur astronomer searching satellite maps for a Quebec camping spot accidentally discovered a massive ancient impact crater. Scientists later found shatter cones that confirmed the ...
NASA Just Powered Up Roman’s Massive 300-megapixel Camera
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NASA’s Roman Space Telescope Could Last More Than Twice as Long as Planned
Sep. 18, 2026 — NASA’s Roman Space Telescope may now have enough fuel for at least 22 years of science, more than double its original 10 year design life. An extremely precise course correction, extra fuel at ...
A $100 Detector Can See Invisible Particles Raining Down from Space
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NASA-backed Scientists Turn Plastic Waste Into Edible Cookies
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