OT: Scientists confirm existence of gravitational waves

This is huge. 

The LIGO project still seems strange to me.  The scientists themselves admit that seismic activity or even a passing freight train can register in their data, and that it is a constant battle to get it right.  How they can ultimately determine this vibration is due to black holes colliding?

My physics knowledge peaked at 17 with AP Physics, but I love reading these threads and the comments from the more intelligent set of MGoBloggers.  I learn something every time I read a thread like this.

Thanks for posting!

When you read the "breaking" story account of this, it basically sounds like they stood outside, held up a microphone and they heard, "Hi! We're gravitational waves!"

WAY TO UNDERSELL YOUR ACCOMPLISHMENTS, SCIENCE. 

Yeah, no flying cars, just confirmation of existing ideas. But pretty huge for a few reasons. We've been searching for them a long, long time. Measuring gravity is hard because it's so weak compared to the other forces (like 10^30 times weaker). So a great experimental and technical accomplishment. And it means people don't have to waste time trying to explain why there _aren't_ gravity waves. 

EDIT: I should also have added that it is a huge milestone along the way to opening up a new subfield in astronomy, that is, gravitational wave astronomy. We should eventually be able to make new measurements (and old measurements in new ways) using gravity waves instead of electromagnetic waves (light, infrared, x-ray, etc.). In fact, some new astrophysics has already been done with this LIGO result as, to my understanding, it implies a relatively high population of black holes in the range of 10's of stellar masses (because it's sensitive to the types of high-frequency gravity waves these things emit in death spirals, and it wasn't on for long, so they seem likely - again, that's my takeaway, but I'm far from a pro physicist, so take it FWIW).

My son is looking at Caltech, who with MIT, are leaders in the LIGO efforts. They also recently "killed" Pluto and predicted a new, unseen ninth planet based on gravitational pull of nearby orbits. Just wow. Here's a LIGO video that is for laypeople like me:

Wow!  Lost in Space was scary-correct!

See.

I'll bet those scientists worked over Spring Break.

If this is indeed true - an awesome discovery.

The only thing that bothers me when I read the article is this section.  Bold emphisis mine:

"On Sept. 14, the system had barely finished being calibrated and was in what is called an engineering run at 4 a.m. when a loud signal came through at the Livingston site. “Data was streaming, and then ‘bam,’ ” recalled David Reitze, a Caltech professor who is the director of the LIGO Laboratory, the group that built and runs the detectors.

Seven milliseconds later, the signal hit the Hanford site. LIGO scientists later determined that the likelihood of such signals landing simultaneously by pure chance was vanishingly small."

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So, the system had just barely finished being calibrated and something got detected?  That's either incredibly conincidental or perhaps once the system was calibrated some part of the system (mirror, support, anything) settled and "snapped" into place.  If the two seperate sites were setup the exact same way, it's plausible the settling of the experiment occurred at the exact same time in those two places.

I have to think the experimenters already ruled this out, but really, RIGHT when you finished calibrating the thing you detect something and it's gold?  And nothing that big since?

EDIT - I'm assuming the calibration being talked about in this article was the first one ever and this experiment was "brought online" for the first time on Sept 14.  If this was just the first calibration of that particular day, then my doubts fade away.  It doesn't seem clear to me from the article if this was the experiement's first run ever or just first run of the day.  I got the impression it was the first run ever, hence the skepticism.