Astronomy Picture of the Day -- Advanced LIGO: Gravitational Wave Detectors Upgraded

NASA ^ | February 07, 2016 | (see photo credit)

[SunkenCiv]

Explanation: Accelerate a charge and you'll get electromagnetic radiation: light. But accelerate any mass and you'll get gravitational radiation. Light is seen all the time, but, so far, a confirmed direct detection of gravitational radiation has been elusive. When absorbed, gravitational waves create a tiny symmetric jiggle similar to squashing a rubber ball and letting go quickly. Separated detectors can be used to discern gravitational waves from everyday bumps. Powerful astronomical sources of gravitational radiation would coincidentally jiggle even detectors on opposite ends of the Earth. Pictured here are the four-kilometer-long arms of one such detector: the LIGO Hanford Observatory in Washington state, USA. Together with its sister interferometer in Louisiana, these gravitational wave detectors continue to be upgraded and are now more sensitive than ever.

[Hebrews 11:6]

Those are some foul lines. You’d need some speedy outfielders in that ballpark.

[FredZarguna]

We are still befuddled over the wave/particle aspect of what we call light.

No one is "befuddled" by it. It is as well understood as the fact that the earth is round.

[SunkenCiv]

What they're doing is called research -- they don't merely rely on received opinion about what is and is not possible.

[SubMareener]

General Relativity requires the postulation of “dark matter” and “dark energy” to make it work at galactic distances.

[JoeFromSidney]

Years ago when I was assigned to Air Force Office of Scientific Research we were funding some gravity wave research at University of Maryland. That was long before LIGO. Back then the preferred way of detecting gravity waves was to use a large metal cylinder (usually aluminum) under the theory that a gravity wave would case the cylinder to "ring," and the vibrations could be detected.

I visited the site one day, as part of my regular duties, and noted that the researchers had bolted a license plate to the side of the case (not the detector itself). The head researcher told me, with a straight face, that this was the only licensed gravity detector in the State of Maryland.

[fieldmarshaldj]

I can’t make any Uranus jokes about this photo. I got nothin’.

[FredZarguna]

Nope, it doesn't. Those are both possibilities but General Relativity doesn't require them per se.

[SubMareener]

Take a look. Tell me what you think. http://public.fh-wolfenbuettel.de/~haeuser/research/STAIFLogNo021.pdf

[SubMareener]

Here is another paper on the subject: http://www.hpcc-space.de/publications/documents/ExtendedHeimTheory.pdf

[zeestephen]

Thanks, Fred, that’s very helpful.

[Red Badger]

It seems to me that Gravitational Waves should be fairly easy to detect..........................

[SunkenCiv]

They should just line up a bunch of apples, worked for Newton...

[Red Badger]

Seems to me that you could measure the absorption lines of a certain element in a star’s spectrograph, via a satellite in constant optical contact with that star, 24 / 7 / 365, then measure the amount of red or blue shift, indicating that star’s direction of movement, either toward or away from the observer. It should be constant, or nearly so.

Then, monitor that star’s spectrum constantly for a long period of time, and check to see if that absorption line moves, either way, up or down the spectrum. That would indicate that a gravity wave had passed between the star and the observer satellite, stretching then contracting the fabric of space-time between............................

Sound okay?..................