Gravitational waves will bring us exquisitely accurate maps of black holes - maps of their space-time. Those maps will make it crystal clear whether or not what we're dealing with are black holes as described by general relativity.
Black holes do not emit light, so you visualize them through gravitational lensing - how they bend light from other objects.
In subjects that physicists think of as purely quantum, classical ideas and classical computational techniques can often be powerful.
When Galileo first trained his optic telescope on the heavens and opened up modern optical astronomy, that was the first of the electromagnetic windows out of the universe: light.
The essential point is that, although coordinates are a powerful, and sometimes essential, tool in many calculations, the fundamental laws of physics can be expressed without the aid of coordinates; and, indeed, their coordinate-free expressions are generally elegant and exceedingly powerful.
We have to have a combination of general relativity that describes the warping of space and time, and quantum physics, which describes the uncertainties in that warping and how they change.
I became interested in this question of whether you can build wormholes for interstellar travel. I realized that if you had a wormhole, the theory of general relativity by itself would permit you to go backward in time.
When gravitational waves reach the earth, the waves stretch and squeeze space. This is a tiny stretch and squeeze. Far too small to detect with ordinary human senses.
We'll have four different gravitational wave windows open within the next 20 years, and each of them will see something different. We'll be probing the birth of the universe with this. The so-called 'inflationary era' of the universe. We'll be probing the birth of the fundamental forces and how they came into being.
When I ask myself what are the great things we got from the Renaissance, it's the great art, the great music, the science insights of Leonardo da Vinci. Two hundred years from now, when you ask what are the great things that came from this era, I think it's going to be an understanding of the universe around us.
Our universe - it's three-dimensional, but we can pretend it's two-dimensional so it's like this sheet of paper - and we live in Pasadena over here and London is over there, and it's thousands of miles from Pasadena to London.
As early as I can remember, I wanted to be a snowplow driver. When you grow up in the Rocky Mountains, like I did, you see the snow drifts piled up six feet high, and you're two feet, so it's impressive.
I wanted to be a snowplow driver when I was a kid. Growing up in the Rocky Mountains, that's the most glorious job you can imagine. But then my mother took me to a lecture about the solar system when I was 8, and I got hooked.
A big misconception is that a black hole is made of matter that has just been compacted to a very small size. That's not true. A black hole is made from warped space and time.
'Closed timelike curve' is the jargon for time travel. It means you go out, come back and meet yourself in the past.
A black hole really is an object with very rich structure, just like Earth has a rich structure of mountains, valleys, oceans, and so forth. Its warped space whirls around the central singularity like air in a tornado.
Each black hole spins on its axis like the Earth spins. That spin creates two vortexes of twisting space, somewhat like vortexes in a bathtub or a whirlpool.
My passion is to understand the non-linear dynamics of warped space-time, and the ideal venue for this is black-hole collisions.
