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Gravity Probe B Confirms Two of Einstein’s Space-Time Theories

[/caption] Researchers have confirmed two predictions of Albert Einstein’s general theory of relativity, concluding one of NASA’s longest-running projects. The Gravity Probe B experiment used four ultra-precise gyroscopes housed in an Earth-orbiting satellite to measure two aspects of Einstein’s theory about gravity. The first is the geodetic effect, or the warping of space and time …

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Astronomy Without A Telescope – Doubly Special Relativity

[/caption] General relativity, Einstein’s theory of gravity, gives us a useful basis for mathematically modeling the large scale universe – while quantum theory gives us a useful basis for modeling sub-atomic particle physics and the likely small-scale, high-energy-density physics of the early universe – nanoseconds after the Big Bang – which general relativity just models …

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This is Getting Boring: General Relativity Passes Yet another Big Test!

[/caption] Published in 1915, Einstein’s theory of general relativity (GR) passed its first big test just a few years later, when the predicted gravitational deflection of light passing near the Sun was observed during the 1919 solar eclipse. In 1960, GR passed its first big test in a lab, here on Earth; the Pound-Rebka experiment. …

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Einstein’s General Relativity Tested Again, Much More Stringently

[/caption] This time it was the gravitational redshift part of General Relativity; and the stringency? An astonishing better-than-one-part-in-100-million! How did Steven Chu (US Secretary of Energy, though this work was done while he was at the University of California Berkeley), Holger Müler (Berkeley), and Achim Peters (Humboldt University in Berlin) beat the previous best gravitational …

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What is Einstein’s Theory of Relativity?

There are two, theories of relativity, by Einstein, the special theory of relativity (or just special relativity, SR), and the general theory of relativity (or just general relativity, GR). The special theory of relativity was published in 1905, in Annalen der Physik (“Zur Elektrodynamik bewegter Körper“, in the original German; “On the Electrodynamics of Moving …

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New Way to Measure Curvature of Space Could Unite Gravity Theory

[/caption] Einstein’s general theory of relativity describes gravity in terms of the geometry of both space and time. Far from a source of gravity, such as a star like our sun, space is “flat” and clocks tick at their normal rate. Closer to a source of gravity, however, clocks slow down and space is curved. …

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Small Engine For the Big Job of Testing Theory of Relativity

[/caption] Researchers from the European Space Agency are testing what they describe as the smallest, yet most precisely controllable engine ever built for space. Measuring 10 centimeters (4 inches) across and making a faint blue glow as it runs, the Field Emission Electric Propulsion, or FEEP, engine produces an average thrust equivalent to the force …

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Cosmologists Search for Gravity Waves to Prove Inflation Theory

[/caption] During the next decade, cosmologists will attempt to observe the first moments of the Universe, hoping to prove a popular theory. They’ll be searching for extremely weak gravity waves to measure primordial light, looking for convincing evidence for the Cosmic Inflation Theory, which proposes that a random, microscopic density fluctuation in the fabric of …

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Inflation Theory Takes a Little Kick in the Pants

Inflation theory proposes that the universe underwent a period of exponential expansion right after the Big Bang. One of the key predictions of inflation theory is the presence of a particular spectrum of “gravitational radiation”—ripples in the fabric of space-time that are really hard to detect but thought to exist. But a team of researchers …

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