Does the gravitational wave contain 0.9 solar masses of energy?
Or in less sensical units, the energy from detonating 1% of our galaxy's mass worth of TNT.
"Which of the following would be brighter, in terms of the amount of energy delivered to your retina:
1. A supernova, seen from as far away as the Sun is from the Earth, or
2. The detonation of a hydrogen bomb pressed against your eyeball?
Answer: the supernova, by nine orders of magnitude."
Just as a nuclear bomb converts a small amount of mass to radiant energy (grams?), a merger can convert mass into other forms of energy, too.
Gravitational waves, of which there are probably many passing through us all the time from many sources, carry a lot of power. The only reason we don't see them every day is that spacetime itself is extremely stiff.
Far away in linear approximation (which is what we saw here), the lattice picture is quite appropriate as a first order analogy.
As energy radiates outwards, it becomes diluted on a sphere that increases its surface area as r^2. Thus the local energy density goes with inverse square law in the distance to the observer. But we don't measure the local energy density of gravitational waves, but the local amplitude. And in wave mechanics energy is the square of the amplitude. So the amplitude goes down with 1/r.
Needless to say, you would not survive if 1 solar mass of energy were released in any other form (even neutrinos). The key feature is that that tremendous amount of energy results in only a minuscule deformation of spacetime, i.e., spacetime is extremely stiff.
By the way, the distances are way smaller than merely subatomic. The strain sensitivity is 10^-21, which for the ~ 1 km arms of LIGO is a shift of just 10^-8 the width of an atom.
But it is close!
A supernova releases "few times 10^45 J of neutrino energy" , so let's say 5. 5e45 J is about 6e28 kg, while solar mass is 2e30 kg. And neutron radiation from a supernova would get fatal when closer than about 2.3 AU . So we have a factor of 30 from the masses and a factor of 5 (1^2 AU vs. 2.3^2 AU) from the distance.
So about 1/150 of solar mass released in neutron radiation would be survivable at the distance of 1 AU.
The formula for gravitational potential energy is just mgh (mass times gravitational acceleration times height), and g is just GM/r^2, so the potential energy of one black hole in the other's gravitational field would be GMm/r, which would be the same for the other, so the total gravitational potential energy would be twice that.
Also, the schwarzschild radius of a black hole is about 3km per solar mass (2e30 kg).
Which means that before their event horizons touch the two black holes should be separated by a distance of at least 65.1 km.
So, 2 * G * 14.2 * 7.5 * (2e30kg)^2 / 65.1 km is...
divide by c^2:
9.7e30 kg or 4.86 solar mass
So the system actually had nearly 5 solar masses of gravitational potential energy in it, some of which was radiated away as gravitational waves.
As more detectors come online they will be able to triangulate more accurately. The next one is supposed to come online in 2018 iirc.