What on Earth is Wrong with Gravity (14 of 20)

What on Earth is Wrong with Gravity

Gravity will probably and hopefully confuse us for a long time before we figure out what it really is, and scientists are happy when confused and chasing something fun.
Rising out of the swamp in the shape of a giant L, this is the Laser Interferometer Gravitational Wave Observatory or LIGO, for short.
Any signal we see is gonna be from something really, really interesting and cool.
Data from those sources would be valuable to learn things about gravity and it's nature.
This machine was built as an observatory, a chance to witness violent galactic events beyond anything we've ever seen before.

One of the things I hope to see is when you get two stars called neutron stars.
A neutron star is probably twice or three times as heavy as the sun, but compressed into a ball about ten kilometres across, so the size of a city.
And there are places where there can be two of those things orbiting around each other at about 100 or even 1,000 times a second.
The incredibly dense neutron stars spin round each other, churning up the space time.
As they spiral in, going faster and faster, Einstein predicts this sort of violent cosmic event will create something called gravitational waves.
But what exactly is a gravitational wave?
It 's not that easy to describe.
If a wave came through this room it'd...what can I say? Eh...ripples, yeah.
Space time isn't just something that's...
you know up there amongst the stars, it's here.
It 's in front of me, and it's inside me.
So, when I move, I disturb it - I send out ripples in it.
It 's just like if I jump into a swimming pool and start swimming.
I'll send out ripples on the surface of the water.
It 's the same with space time.