What, exactly, is space-time?
Few ideas in modern science have reshaped our understanding of reality more profoundly than space-time—the interwoven fabric of space and time at the heart of Albert Einstein's theory of relativity.
Gravitation as a research area investigates the fundamental interaction responsible for the attraction between masses, spanning classical, relativistic, and quantum regimes. It encompasses the study of Newtonian gravity for weak-field, low-velocity systems, general relativity for strong-field and cosmological phenomena, and experimental and observational tests across scales from laboratory to astrophysical and cosmological. The field also includes gravitational wave physics, black hole and neutron star dynamics, precision tests of the equivalence principle, alternative and modified gravity theories, and efforts toward quantum gravity, such as loop quantum gravity, string-inspired models, and semiclassical approaches, with strong connections to cosmology and high-energy theory.
Few ideas in modern science have reshaped our understanding of reality more profoundly than space-time—the interwoven fabric of space and time at the heart of Albert Einstein's theory of relativity.
Astronomy
Aug 25, 2025
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A research team led by Prof. Jiao Chengliang at the Yunnan Observatories of the Chinese Academy of Sciences, along with collaborators, has introduced a self-consistent model that addresses long-unresolved theoretical gaps ...
Astronomy
Aug 22, 2025
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We're often told it is "unscientific" or "meaningless" to ask what happened before the Big Bang. But a new paper by FQxI cosmologist Eugene Lim, of King's College London, UK, and astrophysicists Katy Clough, of Queen Mary ...
Astronomy
Aug 21, 2025
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It sounds like science fiction: a spacecraft, no heavier than a paperclip, propelled by a laser beam and hurtling through space at the speed of light toward a black hole, on a mission to probe the very fabric of space and ...
Astronomy
Aug 7, 2025
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Black holes embody the ultimate abyss. They are the most powerful sources of gravity in the universe, capable of dramatically distorting space and time around them. When disturbed, they begin to "ring" in a distinctive pattern ...
Astronomy
Jul 31, 2025
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A team of scientists led by expert Raúl Jiménez, ICREA researcher at the University of Barcelona's Institute of Cosmos Sciences (ICCUB), in collaboration with the University of Padua (Italy), has presented a revolutionary ...
General Physics
Jul 15, 2025
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In physics, there are two great pillars of thought that don't quite fit together. The Standard Model of particle physics describes all known fundamental particles and three forces: electromagnetism, the strong nuclear force, ...
Quantum Physics
Jul 11, 2025
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A new study has revealed a novel effect caused by dark photons—hypothetical particles thought to make up a portion of the universe's elusive dark matter. This discovery, made within the framework of Einstein–Cartan–Holst ...
General Physics
Jun 3, 2025
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In 2015, a piece of equipment at an observatory in the US moved one quintillionth (10-18) of a meter. This tiny movement was the first recorded event of gravitational waves. And it helped confirm Einstein's theory of general ...
Astronomy
May 28, 2025
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We have long taken it for granted that gravity is one of the basic forces of nature—one of the invisible threads that keeps the universe stitched together. But suppose that this is not true. Suppose the law of gravity is ...
General Physics
May 13, 2025
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