I'm teaching a high school science class right now called "Are We Alone?" It's a survey class of what kind of objects exist in the Universe, and how we're scientifically attempting to answer the question of whether life exists anywhere other than Earth.

It's going to be fun sharing this with the class today!

We ramped up capacity. Massive traffic! Also, if you are looking for a good article on this from a field expert, we have a Physics Viewpoint on it here: http://physics.aps.org/articles/v9/17

I also enjoyed the article on the LIGO site at http://www.ligo.org/science/Publication-GW150914/index.php

Solid coverage without the fluff.

LIGO's mirror: https://dcc.ligo.org/public/0122/P150914/014/LIGO-P150914%3A...

It's a wonderful data and a well-written paper. Really just remarkable.

They have a few minor events that seem less likely to lead to anything, but to capture a big one like this at the start of 16 days of collection is a gift.

Thank you for posting a direct link to the paper!

B.P. Abbott must be getting a lot of inquiries :)

Edit: Abbott is, when alphabetically arranged, the first name of a long list of authors.

Is this paper mirrored anywhere else yet? The Phys. Rev. Letters site appears to be a bit overloaded!

Here's the abstract:

On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak gravitational-wave strain of 1.0×10−21. It matches the waveform predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203 000 years, equivalent to a significance greater than 5.1σ. The source lies at a luminosity distance of 410+160−180  Mpc corresponding to a redshift z=0.09+0.03−0.04. In the source frame, the initial black hole masses are 36+5−4M⊙ and 29+4−4M⊙, and the final black hole mass is 62+4−4M⊙, with 3.0+0.5−0.5M⊙c2 radiated in gravitational waves. All uncertainties define 90% credible intervals. These observations demonstrate the existence of binary stellar-mass black hole systems. This is the first direct detection of gravitational waves and the first observation of a binary black hole merger.

I dabbled with GR many years ago, so I'd have been surprised if this hadn't turned up sooner or later... but My God, look at that... three earth masses-worth of radiated gravitational energy, I can hardly fathom that.

I think that's three solar masses.

My bad, you're right — my astonishment has risen by orders of magnitude.

Intermediate mass black holes are 100 to 1 million solar masses.

I understand frequency, SNR and significance. The other numbers are mysterious to me; anyone who understands the entirety of this abstract care to explain what the other numbers mean?

Possibly simpler than it looks.

410Mpc = 410 megaparsecs, which is about 1.3 billion light years

62M⊙ = 62 x the mass of the sun

The values have 90% error bars:

62+4−4M⊙ = 62 +/-4 solar masses

As the comments below say, the abstract says that three whole solar masses were converted to gravity waves when the black holes merged.

I'm not sure what the state of research into black hole mergers is, but the science that explains that number is going to be really interesting.

Thanks...but it was the rest of the paper itself I was wanting to look at! Trying to download the pdf...along with a fair few other from the slowness of the site.

Just to add a sense of scale, the co-moving distance to that back hole merge is roughly 1/60th the diameter of the observable universe!

Simultaneously? Are we sure?

(Joking, kind of...)

That's some serious history of physics nerd funny - it's reference to a very embarrassing failure to include time zone discrepancies when analyzing some of the first gravity wave data back in the 1960's

Woohoo, thank you!

Thank you!

wow, I hope some of my APS member dues go to improving the servers!