By complete coincidence, last night I had my amateur radio telescope pointed at a certain part of the sky. I had left the recording equipment on, and when I played it back this morning there was this strange message:
Thy micturations are to me
As plurdled gabbleblotchits in a lurgid bee.
Group, I implore thee, my foonting turlingdromes,
And hooptiously thrangle me with crinkly bindlewurdles,
For otherwise I will rend thee in the gobberwartswuh
With my burglecruncheon."
See if I don't!"
Black holes...That explains where all my spoons, biros, unicorns, and my wife's hair-clips that keep disappearing end up in. In order to find the Black Hole, we simply follow a large number of my smelly socks to their destination ((nah, the Unicorns are down to Noah; the silly sod got so drunk and confused he filled the Ark with the reject list, so instead of Unicorns, Centaurs, Mimsy Borogroves & c we ended up with the poisonous snakes and spiders, naked mole rats and the various parasites, viruses and such that infest the world now thanks to Noah's love of booze. Of course the book makes him out to be a hero, but who do you think wrote it? He and his family are the only people left, no wonder it's a hagiography! Hell, you don't want to hear what he got up to with the Mermaids!).
I wish we had a theory of quantum gravity.
What we describe as waves in a sea of energy aren't real waves but a representation of probabilities at locations. Particles can come in and out of existence at random, but they may hang around for quite a long time. Long enough to bind together into atoms, which accrete into a planet and eventually get taken up by a tree which is cut down to make my chair. The only visible signal would be if some material around the black holes started crashing together. The energy from the black holes themselves spiralling in just comes out as gravitational waves. You get visible light from the accretion disks of black holes, which are typically pulled off companion stars. But binaries both of whose components are black holes don't have companion stars, and hence have no accretion disks. So they are expected to be very dark electromagnetically. Energy doesn't have to be visible.
Gravity waves are it. I don't know that you would necessarily see any "visible signal", unless by "visible" one simply meant detectable, e.g. visible telemetry data. In which case it's exactly what LIGO and VIRGO are doing as Clegg shows.