<p>I think the <a href="https://en.wikipedia.org/wiki/Gravitational-wave_astronomy#Science_potential" rel="noreferrer">wikipedia</a> page gives a reasonable overview of why gravitational waves give us a window on the universe that is either not observable or is complementary to the view we get from electromagnetic waves (or neutrinos).</p>

<p>But let's have a specific example. The potential of LIGO, as we have seen today, is to detect the gravitational wave signatures of merging black hole binaries.</p>

<p>The power radiated in gravitational waves strongly depends on the orbital separation of the black holes, it also depends on their masses. The frequency of the radiation will change as the black holes spiral together. The "noise" that this makes in the final few seconds as the black holes merge is the "chirp" that is detected by LIGO. Have a look (listen!) to what a chirp might "sound" like at this web page from <a href="http://www.sr.bham.ac.uk/gwastro/what-are-we-looking-for" rel="noreferrer">University of Birmingham</a>.</p>

<p>The exact characteristics of the chirp (duration, frequency etc.) can for instance yield the masses of the black holes and of their final configuration and may tell us about spin rates of the black holes. Yet these same mergers may produce zero electromagnetic wave signatures that could be seen by conventional telescopes.</p>

<p>Furthermore, because the amplitude and the frequency of the waves depend differently on the masses and <em>distance</em> to the GW source, these binary chirps acts as "standard candles" in a similar way to type Ia supernovae. In other words, measurements of the chirp independently gives the masses of the merging black holes <em>and</em> the distance to them.</p>

CC BY-SA 3.0
2016-02-10T12:48:45.123Z
2016-02-11T22:59:00.453Z
2016-02-11T22:59:00.453Z
ProfRob
<p>Before reading this question, you should read <a href="http://www.ligo.org/news/media-advisory.php" rel="noreferrer">this paper.</a></p>
<p>From what I understood, we managed to detect gravitational waves for the first time.</p>
<p>Is this discovery going to help us understand something we haven't understood yet? Dark matter? Galaxy movements? FTL travel? Gravity manipulation, Interstellar style?</p>
<p>Though I understand the discovery, I'm a little confused about what it will actually improve for science.</p>
<p>So, what are the doors this discovery will open ?</p>

CC BY-SA 3.0
2016-02-10T11:28:36.880Z
From an Astronomical perspective, gravitational waves provide us with a completely new way of gathering information on astronomical objects. Currently the only way that we can learn about objects beyond our reach is through the light they emit.
christopherlovell
CC BY-SA 3.0
2016-02-10T12:53:45.357Z
@RobJeffries : I read an article yesterday in a French newspaper announcing the discovery... I am totally aware of the fact that this newspaper probably knows nothing about what it is speaking about, but I thought this was an anouncement. My bad !
Nico
CC BY-SA 3.0
2016-02-10T14:31:18.273Z
But you linked to a page that quite clearly says that there *will* be a press conference tomorrow. Yes, the media is awash with *rumours* about what will be announced.
ProfRob
CC BY-SA 3.0
2016-02-10T18:08:33.133Z
I thought [this summary](http://www.nature.com/news/gravitational-waves-6-cosmic-questions-they-can-tackle-1.19337) gave some good ideas.
Warrick
CC BY-SA 3.0
2016-02-11T03:23:01.783Z
Since waves seem to be associated with particles, I wonder if detection of gravitational waves would infer gravitons?
Jack R. Woods
CC BY-SA 3.0
2016-02-11T17:19:00.570Z
Well, now it is announced!
ProfRob
<gravity><gravitational-waves>
What do gravitational waves allow us to understand?
Nico
# What do gravitational waves allow us to understand?

(Asked by: username_0 on 2016-02-10)

Before reading this question, you should read [this paper.](http://www.ligo.org/news/media-advisory.php)

From what I understood, we managed to detect gravitational waves for the first time.

Is this discovery going to help us understand something we haven't understood yet? Dark matter? Galaxy movements? FTL travel? Gravity manipulation, Interstellar style?

Though I understand the discovery, I'm a little confused about what it will actually improve for science.

So, what are the doors this discovery will open ?

**Tags:** gravity, gravitational-waves

> **Comments:**
> **username_1**: From an Astronomical perspective, gravitational waves provide us with a completely new way of gathering information on astronomical objects. Currently the only way that we can learn about objects beyond our reach is through the light they emit.  
> **username_0**: @RobJeffries : I read an article yesterday in a French newspaper announcing the discovery... I am totally aware of the fact that this newspaper probably knows nothing about what it is speaking about, but I thought this was an anouncement. My bad !  
> **username_2**: But you linked to a page that quite clearly says that there *will* be a press conference tomorrow. Yes, the media is awash with *rumours* about what will be announced.  
> **username_3**: I thought [this summary](http://www.nature.com/news/gravitational-waves-6-cosmic-questions-they-can-tackle-1.19337) gave some good ideas.  
> **username_4**: Since waves seem to be associated with particles, I wonder if detection of gravitational waves would infer gravitons?  
> **username_2**: Well, now it is announced!  

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## 1 answers

### Answer by username_2 on 2016-02-10. Score: 8 | Accepted answer

I think the [wikipedia](https://en.wikipedia.org/wiki/Gravitational-wave_astronomy#Science_potential) page gives a reasonable overview of why gravitational waves give us a window on the universe that is either not observable or is complementary to the view we get from electromagnetic waves (or neutrinos).

But let's have a specific example. The potential of LIGO, as we have seen today, is to detect the gravitational wave signatures of merging black hole binaries.

The power radiated in gravitational waves strongly depends on the orbital separation of the black holes, it also depends on their masses. The frequency of the radiation will change as the black holes spiral together. The "noise" that this makes in the final few seconds as the black holes merge is the "chirp" that is detected by LIGO. Have a look (listen!) to what a chirp might "sound" like at this web page from [University of Birmingham](http://www.sr.bham.ac.uk/gwastro/what-are-we-looking-for).

The exact characteristics of the chirp (duration, frequency etc.) can for instance yield the masses of the black holes and of their final configuration and may tell us about spin rates of the black holes. Yet these same mergers may produce zero electromagnetic wave signatures that could be seen by conventional telescopes.

Furthermore, because the amplitude and the frequency of the waves depend differently on the masses and *distance* to the GW source, these binary chirps acts as "standard candles" in a similar way to type Ia supernovae. In other words, measurements of the chirp independently gives the masses of the merging black holes *and* the distance to them.


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