Saturday, September 1, 2012

Searching evidence about gravitational waves

Spacetime curvature was suggestsed by Einstein
BBC Future 31. August 2012 has an article by award winning science writer Philip Ball that tells with admirable clarity about current search for proof of the existence of gravitational waves predicted by Einstein in 1916 in his general theory of relativity.

There is a fascinating new European Union project to build an Einstein telescope that would be able to catch such extremely difficult to measure ripples of cosmic waves caused by gravity curving the spacetime continuum.

Philip Ball also tells about the theory that detectable gravitational waves might be created under the extreme conditions in the collapsed remains of stars called neutron stars. Following are some excerpts of the article(with my subtitles).Read the entire text in this link

Fundamental unity of micro- and macro-cosmos
"One thing physics has taught us is that events at the smallest possible scales can have consequences of cosmic proportions. And, in turn, studying some of the universe’s most spectacular astrophysical phenomenon can reveal a lot about physics at its most elementary level.

The latest example of this has been proposed by a team of researchers in Europe – they say that studying the contours of burned-out remnants of stars thousands of light years away could provide concrete evidence for two of the most sought-after phenomena in fundamental physics."

Gravitational waves by analogy
"The first phenomenon, gravitational waves, was predicted by Einstein’s theory of general relativity, which explained the force of gravity as a curvature in spacetime induced by mass. Einstein’s theory is typically illustrated by depicting spacetime as if it resembled a rubber sheet, which a heavy object (such as a star or planet) bends down into a dimple, into which other objects can roll. In this analogy, a disturbance of the heavy mass can produce a ripple in the sheet, radiating outwards like a splash in a pond. This is a gravitational wave, which carries away some energy from the source. When a gravitational wave passes by, it distorts spacetime so that distances get very slightly shorter or longer in the direction of the wave."

Is there quark matter?
"The second sought-after phenomena in fundamental physics. It supposes that the incredibly high density of the star could squash its atoms not into neutrons but into a sea of the still more fundamental particles of which atomic nuclei are made: quarks.

It’s not known if this “quark matter” can really exist. Some hope that it might be sighted in the Large Hadron Collider particle accelerator at CERN in Geneva, but a better bet could be to search for its signature in neutron stars – which would then in fact be quark stars, most probably with a core of quark matter coated with ordinary matter such as neutrons."
Philip Ball BBC Science

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