Mission Control Is A Unique Environment.  The People Who Work There Are The Cream Of The Crop.  The

"So I got started working on black holes my first year in graduate school.  I actually tried another research project first about cosmology, but frankly the math was just too difficult for me, so I decided to go into easier things: black holes."

I love astrophysics and especially black holes and I want to pursue a career on them, but to be honest I'm scared to be not good enough or not clever enough. How did you decide to work on black holes? How did you become the person you are today?

"So, I think we're studying them simply because they're fascinating.  This is how a lot of pure science is motivated.  What are the questions about the world around us that fascinate us, and for me at least black holes is at the top of that list.  If we're looking for more technical applications, like is it going to make the next new cell phone work better?  Probably not.  

But a hundred years from now we really never know where some of these pure science ideas are going to go.  For example, if you think about electricity and magnetism and quantum mechanics a hundred years ago, similairly in the pure pure science realm and now they dominate every aspect of our lives."

Why are we studying them? What’s purpose of this field for us on earth?

Joy is great motivator to do things to do.  And that's actually some advice that I have is whatever you're doing in life, make sure that it brings you some joy.  But there's a lot of reasons that people do things, and I think one of the really great things about being an astronaut is getting a chance to explore.  

We get to do things that are absolutely amazing.  And when we see the planet, we explore outer space, and we get to do all these things and we can come back and we can tell people about it.  So I think it's the thrill of science.  I think it's the lure of discovery.  And then the opportunity to share that with the world is really amazing.

Other than joy, why do you do the things you do?

"So I think what we mean when we say a "gentle" black hole is probably that there's not a lot of hot gas, x-rays, gamma rays, relativistic jets around the black hole.  That makes it safe to go closer to.  In terms of that actually, the supermassive black hole in the center of our Milky Way galaxy, Sagittarius A*, is a pretty gentle black hole.  But even so it still would be far too dangerous to get close to and survive."

Is there such thing as a ‘gentle black hole’ (as in Interstellar) that would one day be a candidate for sending probes? Or is it a lost cause?

Other than flying in combat in my military days, I would say my time at NASA when I've been exploring--probably the scariest time that I had was taking off in the ER-2 behind me on the island of Oahu off a cliff into the ocean of Kaneohe Bay.  

And the reason for that is it climbs up so steep on initial take-off that at night you just go into pitch black, and all you can see is dark sky and dark water, so you can't tell what's what.  And that gets a little unnerving for about the first minute or two of the flight until you know your way up and away from the water.  Otherwise it's a little disorienting and you could be diving into the water.

Have you ever been scared while flying? What was the event that scared you the most?What's your favorite plane to fly?

Yeah, so the human body changes a lot when you're in space. There's things that happen like fluid shifts, since you don't have gravity drawing the fluid down into your legs, all that fluid shifts upwards.  And the body can adjust to this, it does this by just getting rid of the excess fluid.  When you come back to Earth, however, you're a little bit dehydrated.  So one of the things we do is get fluid in right away.  

Another thing that's concerning is things like bone loss aor muscle loss, so what we do to prevent most of that on board is actually just work out a lot.  We have a device called ARED, which is a Resistive Exercise Device, and we have a whole gym's worth of weight-lifting exercises.  We do that, we do running, and we do cycling.  And that can counteract most of the muscle loss and the bone loss we see on board.  We're really successful in returning astronauts in pretty good health these days.

Is your health affected from being in outer space?

"So the way we understand that black holes form is when a massive star basically runs out of fuel and collapses in on itself.  And the reason that happens is because, the reason stars don't collapse in on themselves on a regular day is because they're hot.  

Hot gas has pressure, so you have all this gas pushing out, you have gravity pulling in and you get a nice balanced equilibrium.  But eventually you run out of fuel, so you run out of temperature, you run out of pressure, and the gravity wins.  So the gravity just pulls in and there's not enough hot gas to hold it up anymore.  

That's how they form.  How do they move?  They move pretty much like every other star in the galaxy.  Mostly orbiting around, for example in the solar system, orbiting around the center of the galaxy with a little bit of random motions here and there."

How do blackholes form and how do they move ?

Yeah, flying's great.  It's a completely different sensation.  You know, you can compare parts of it to things like riding a bicycle, skateboarding, surfing, things like that - even skydiving.  It's a real feeling of freedom when you're actually controlling *makes wing gestures* the aircraft flying through the air - a little bit like a bird. 

And that's an amazing privilege to have, and it's really a nice opportunity to get up there and maneuver in three dimensions - really four dimensions if you consider speed - through the earth's atmosphere.  I absolutely love it.

How does flying feel?

Yeah, that's a great question and that's exactly how it feels.  Once we get up about 13 miles above the earth, and get everything set up and start doing the science collection, every now and again you have to kind of stop and just take a minute to look around.  And it's a fascinating sight up there.  

On a normal clear day looking down at the earth, you can see the curvature of the earth out in front of you, and then the sky is just a really dark purple up there because you're above all the moisture in the air that causes the dark blue to turn to light blue down towards the earth's surface.  And it's such a different sight, it really makes you understand how small we really are.

What does it feel like to be up there and look down at the Earth? I've always imagined it would send me into a moment where I feel so small compared to the expanse and beauty of Earth.

So when I was inside the space station, one of my favorite things to do was go in the Cupola, which is an area that has a whole bunch of windows.  You can actually get your whole body into the Cupola and just see the Milky Way and the universe from the Cupola.  And that was amazing.  

It was, um–you know terrifying is almost a good word because it was so awe-inspiring to just be in the universe and see the stars–but it was one of the most interesting things to do because it was always changing.  Your view was changing as you go around the planet; even at nighttime you can see different aspects of the planet at night as well. 

And so whenever I could, I would spend a few minutes when we were in a dark orbit and just try to poke my head into the Cupola and see the stars. It never got old.

What is like to be surrounded by the stars and darkness? Is it terrifying or calming?