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 …

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. …

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 …

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 …

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 …

Supermassive Black Holes Spin at the Limits of Relativity

You know the saying: nothing, not even light can escape a black hole. That makes them invisible. Amazingly, researchers from the University of Maryland have determined how fast a supermassive black hole is spinning. You won’t be surprised to know it’s spinning insanely fast, at the limits predicted by relativity. The researchers used ESA’s XMM-Newton …

Pulsars Confirm Einstein’s Theories

Einstein was right. Well, according to new observations of a double pulsar, he was at least 99.95% right. An international team of astronomers have been measuring the pulsar pair for three years, and have detected several effects that match Einstein’s theory of general relativity. It’s believed the two pulsars are losing energy through the radiation …

Dark Energy Could be a Breakdown of Einstein’s Theory

Cosmologists from Princeton are working on new tests that could help to explain the nature of “dark energy”, a mysterious force accelerating the expansion of the Universe. It could be an unknown form of energy, or it could be that Einstein’s General Theory of Relativity breaks down at very large scales. The researchers will track the rate at which galaxy clusters have grown in time. If this growth is consistent, it’ll mean that dark energy is at work; otherwise, it could mean problems with Einstein’s predictions.