Gravitational Waves: first direct evidence

[Rain]

On a snowy St. Patrick’s Day, our offices officially shut down by a late-winter storm, the Science News staff was abuzz over the biggest thing since the Higgs boson. On March 17, scientists announced the first direct evidence of the theory of cosmic inflation: primordial gravitational waves. The news spread fast, even rippling out to the front page of the New York Times.

Cosmic expansion was one of the most important discoveries of the 20th century; before Einstein and Hubble, people assumed the universe was static. Explaining the universe’s expansion led to the idea of the Big Bang and later to inflation (SN: 7/28/12, p. 20): a moment of explosive, exponential growth in the moments after the Big Bang that accounts for the uniformity of the visible universe, among other things. The universe grew from a speck smaller than a proton to something more akin to a softball in a tiny fraction of a second. Soon after, the theory goes, the ballooning universe slowed down to a more leisurely pace.

Working at home and listening in to a glitchy webcast of the press conference, astronomy writer Christopher Crockett reported the biggest science story in months, if not years. As he describes in our lead news story, scientists have discovered the signatures of primordial gravitational waves in the cosmic microwave background, leftover radiation from the early universe. This offers the strongest evidence to date for inflation, and suggests a universe more vast than once imagined. The gravitational waves were stronger than expected, which gives some skeptics pause. But, as one of Crockett’s sources told him, that will also send theorists running to the blackboard to try to explain the discrepancy. If confirmed by other teams and data from the Planck mission, this could lead to new physics.

Tom Siegfried reports on some other intriguing data from the Planck mission in "Cosmic Question Mark." In his Context blog, Siegfried also tackles the latest news by filling in the backstory of the search for gravitational waves and calling the discovery “a landmark in the history of physics.” He points out that, in most models, if you have inflation, you also get multiverses. For the starry-eyed, that’s news worthy of some big buzz.

Gravitational wave detection a big day for the Big Bang | Science News

 

[Hamartia Antidote]

Rumors Are Flying That We Finally Found Gravitational Waves 

Excited rumors began circulating on Twitter this morning that a major experiment designed to hunt for gravitational waves—ripples in the fabric of spacetime first predicted by Albert Einstein—has observed them directly for the very first time. If confirmed, this would be one of the most significant physics discoveries of the last century.

Move a large mass very suddenly—or have two massive objects suddenly collide, or a supernova explode—and you would create ripples in space-time, much like tossing a stone in a still pond. The more massive the object, the more it will churn the surrounding spacetime, and the stronger the gravitational waves it should produce. Einstein predicted their existence in his general theory of relativity back in 1915, but he thought it would never be possible to test that prediction.

LIGO (Laser Interferometer Gravitational Wave Observatory) is one of several experiments designed to hunt for these elusive ripples, and with its latest upgrade to Advanced LIGO, completed last year, it has the best chance of doing so. In fact, it topped our list of physics stories to watch in 2016.


There have been excited rumors about a LIGO discovery before, most notably a mere week after the upgraded experiment began operations last fall. Lawrence Krauss, a physicist at Arizona State University, spilled the beans on Twitter, giving it a 10- to 15-percent chance of being true. “The official response is that we’re analyzing the data,” LIGO spokesperson Gabriela González (Louisiana State University) told Nature at the time.

 

[Providence]

Gravitational waves will fill a huge void in the understanding of gravity which exists today.

It's detection is a tough job. A tow truck moving at slow speeds 5 miles away from the setup can produce the same gravitational effect as a true wave hitting earth would produce.

 

[ultron]

Gravity is curvature in spacetime. It's not a wave. Fake evidence.

 

[django]

Gravity is curvature in spacetime. It's not a wave. Fake evidence.

We may describe electromagnetic forces as particles responding to the presence of electric and magnetic fields, or we may describe them as resulting from the exchange of virtual photons. These views seem similarly incompatible, but nevertheless both theories (classical electrodynamics and quantum electrodynamics, respectively) give excellent predictions. We can't really say that one is more "right" than another; we just have to accept them both.The situation with gravity is pretty much a direct analogy to electromagnetism. We may describe gravity as particles responding to the presence of spacetime curvature, or we may describe them as resulting from the exchange of virtual gravitons. As with EM, these views would correspond to classical gravity and quantum gravity, respectively. But the difference is, although general relativity fills the role of the classical theory, we don't have a good quantum theory of gravity yet. Perhaps an enlightened mind such as your good self could come up with some groundbreaking theory to put us all out of our misery.kudos my dear chap.

 

[Providence]

Gravity is curvature in spacetime. It's not a wave. Fake evidence.

And the curvature of spacetime can change. The troughs and highs produced will comprise a wave and since such twists can only be produced by a rapidly oscillating pair of gravity source, hence it's called a gravitational wave.

Nobody is saying gravity a wave. Read article properly next time.

 

[Maarkhoor]

I believe any accelerating mass would produce a gravitational wave, right? We look for massive objects accelerating violently because that’s the only way the magnitude is remotely measurable.

 

[AZADPAKISTAN2009]

YAWN MORE ....dreamlike prediction

we barely can send a probe to pluto