quantumaniac: Gravitational Waves In 1916, Albert Einstein revolutionized the physics world with his theory of general relativity. This theory was the first to predict the existence of gravitational waves - a fascinating concept. Gravitational waves are effectively ripples in the curvature of spacetime which travel outward from the source - sources could possibly include binary star systems composed of white dwarfs, neutron stars or black holes. Gravitational waves cannot exist in the Newtonian theory of gravitation, since in it physical interactions propagate at infinite speed. Einstein’s theory of general relativity effectively states that gravity is a phenomenon due to the curvature of spacetime. Massive objects cause this curvature - with mass being roughly proportional to the strength of the curvature that object produces. As massive objects move around in spacetime, this curvature inevitably changes. In general, gravitational waves are produced by objects whose motion include acceleration and are not symmetric (examples of symmetrical motion would be an expanding balloon or spinning cylinder). When accelerated, these objects would cause disturbances in spacetime which would spread like ripples on the surface of a pond. This disturbance is known as gravitational radiation - which is thought to travel at the speed of light and never stop or slow down, yet weaken with distance.  Although gravitational radiation has not been directly detected, there is indirect evidence for its existence. The 1993 Nobel Prize in Physics was awarded for measurements of the Hulse-Taylor binary system, which suggests that gravitational waves are much more than mere mathematical anomalies. gravitational wave detectors exist, yet they remain unsuccessful in detecting such phenomena.
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quantumaniac:

Gravitational Waves

In 1916, Albert Einstein revolutionized the physics world with his theory of general relativity. This theory was the first to predict the existence of gravitational waves - a fascinating concept. Gravitational waves are effectively ripples in the curvature of spacetime which travel outward from the source - sources could possibly include binary star systems composed of white dwarfs, neutron stars or black holes. Gravitational waves cannot exist in the Newtonian theory of gravitation, since in it physical interactions propagate at infinite speed.

Einstein’s theory of general relativity effectively states that gravity is a phenomenon due to the curvature of spacetime. Massive objects cause this curvature - with mass being roughly proportional to the strength of the curvature that object produces. As massive objects move around in spacetime, this curvature inevitably changes. In general, gravitational waves are produced by objects whose motion include acceleration and are not symmetric (examples of symmetrical motion would be an expanding balloon or spinning cylinder). When accelerated, these objects would cause disturbances in spacetime which would spread like ripples on the surface of a pond. This disturbance is known as gravitational radiation - which is thought to travel at the speed of light and never stop or slow down, yet weaken with distance. 

Although gravitational radiation has not been directly detected, there is indirect evidence for its existence. The 1993 Nobel Prize in Physics was awarded for measurements of the Hulse-Taylor binary system, which suggests that gravitational waves are much more than mere mathematical anomalies. gravitational wave detectors exist, yet they remain unsuccessful in detecting such phenomena.

(via logicianmagician)

Source: quantumaniac

the-star-stuff: Dark Energy Confirmed: How ancient sound waves shaped the entire universe Just 30,000 years after the Big Bang, the universe started singing. Vast soundwaves rang out and expanded through the primordial cosmos, their ripples determining the universe’s large-scale structure. And this all fits perfectly with one particularly theory of dark energy. The Baryon Oscillation Spectroscopic Survey, or BOSS, has just completed a massive survey of a whopping 327,349 galaxies. These galaxies are on average about six billion light-years away, which was quite possibly the most momentous time in the universe’s history since the Big Bang itself. Six billion years ago, the universe reached a tipping point, where the matter in the universe became spread out enough that the force of gravity could no longer slow down the universe’s attraction. Instead, the repulsive force of dark energy took hold, and the universe has been speeding up its expansion ever since. [Continue reading… arXiv via BBC News. Illustration by Pixel Embargo/Shutterstock]
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the-star-stuff:

Dark Energy Confirmed: How ancient sound waves shaped the entire universe

Just 30,000 years after the Big Bang, the universe started singing. Vast soundwaves rang out and expanded through the primordial cosmos, their ripples determining the universe’s large-scale structure. And this all fits perfectly with one particularly theory of dark energy.

The Baryon Oscillation Spectroscopic Survey, or BOSS, has just completed a massive survey of a whopping 327,349 galaxies. These galaxies are on average about six billion light-years away, which was quite possibly the most momentous time in the universe’s history since the Big Bang itself. Six billion years ago, the universe reached a tipping point, where the matter in the universe became spread out enough that the force of gravity could no longer slow down the universe’s attraction. Instead, the repulsive force of dark energy took hold, and the universe has been speeding up its expansion ever since.

[Continue reading… arXiv via BBC News. Illustration by Pixel Embargo/Shutterstock]

fuckyeah-chemistry: So here’s the deal. Three astronomers, Saul Perlmutter, Brian P. Schmidt, and Adam G. Riess won the Nobel Prize for physics this week. Why is this interesting? Becuase of what they discovered. With the help of a type 1a supernova (a type of exploding star) theydiscovered that the expansion of the universe is actually speeding up, due to an antigravitatonal force called “dark energy.” Although they don’t know exactly what dark energy is, they do know that it’s pushing galaxies apart. An article in the New York Times states that “If the universe continues accelerating, astronomers say, rather than coasting gently into the night, distant galaxies will eventually be moving apart so quickly that they cannot communicate with one another and all the energy will be sucked out of the universe.” Poor Einstein, they believe that there are a bunch of different universes with different properties (obviously we live in one that is habitable). Pretty cool, eh?
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fuckyeah-chemistry:

So here’s the deal. Three astronomers, Saul Perlmutter, Brian P. Schmidt, and Adam G. Riess won the Nobel Prize for physics this week. Why is this interesting? Becuase of what they discovered. With the help of a type 1a supernova (a type of exploding star) theydiscovered that the expansion of the universe is actually speeding up, due to an antigravitatonal force called “dark energy.” Although they don’t know exactly what dark energy is, they do know that it’s pushing galaxies apart. An article in the New York Times states that “If the universe continues accelerating, astronomers say, rather than coasting gently into the night, distant galaxies will eventually be moving apart so quickly that they cannot communicate with one another and all the energy will be sucked out of the universe.” Poor Einstein, they believe that there are a bunch of different universes with different properties (obviously we live in one that is habitable). Pretty cool, eh?