Laser Observatory May Directly Detect Gravity Waves

Atmospheric Gravity Waves as seen from Space - Satellite image of Atmospheric
Gravity Waves over the Arabian Sea. Their visibility is due to sunglint, caused by
the "impression" of the atmospheric waves on the sea surface.
(Image Sources: NASA, Wikipedia.org )

By Kenneth Hicks, Professor of Physics and Astronomy, Ohio University in Athens
The Columbus Dispatch

Astronomers typically use telescopes of one sort or another to explore what’s going on in the cosmos.

But a new type of astronomy, one that uses a different apparatus that can measure gravitational waves, could be on the verge of making history.

Most telescopes collect light, which is an electromagnetic wave. Even radio telescopes operate on this principle; the only difference is that radio waves have a longer wavelength than light waves.
But electromagnetism is not the only way to make waves. According to Einstein’s theory of general relativity — 100 years old this year — gravity also can make waves as ripples in space-time.
How would you build a device to see gravitational waves?

The answer is the Laser Interferometer Gravitational-Wave Observatory, or LIGO, which began as a collaboration of scientists in 1997 and just started recording data in mid-September.

The observatory uses a laser to precisely measure the length of two perpendicular arms, each 2.5 miles long. The technique, called interferometry, can measure the change in length to better than a fraction of a wavelength. This kind of precision is necessary because gravitational waves slightly expand one arm while contracting the other.

There are two LIGO facilities — one in the desert near Hanford, Wash., and the other near Livingston, La. Two facilities are needed because if one sees a gravitational wave, the other can confirm it. Both facilities are required to be in operation at the same time to avoid any false signals.

“I believe the first direct detection of gravitational waves by ... LIGO will excite the scientific community,” Madeline Wade said.

More - Link >>> http://www.dispatch.com/content/stories/science/2015/10/04/1-new-observatory-to-track-gravitational-waves.html

More on the Laser Interferometer Gravitational-Wave Observatory (LIGO):
Link >>> https://en.wikipedia.org/wiki/LIGO

More on Gravity Waves: Link >>> https://en.wikipedia.org/wiki/Gravity_wave

Related Blog Post ---

"Gravity Waves Found: Strong Evidence of Big Bang Theory." 2014 March 17.

Link >>> http://spacewatchtower.blogspot.com/2014/03/gravity-waves-found-strong-evidence-of.html

Sources: The Columbus Dispatch, Ohio University in Athens.

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