"So The Way We Understand That Black Holes Form Is When A Massive Star Basically Runs Out Of Fuel And

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?

Yes, there’s several paths to get to where I am right now and where the other researcher pilots are here at NASA.  We have some that come up through civilian flying and they’re educated in different areas.  Typically most of us have engineering or STEM related degrees in college, and usually Masters degrees on top of that. 

The flying portion, most of us actually come from a military background because that’s the best way to get a lot of intense experience very quickly.  So most of us are retired military pilots from all different services, but then we do have several pilots who have grown up flying corporate jets, larger airplanes and became test pilots for companies like, say, Boeing and Lockheed Martin, things like that.  And then they get hired at NASA based on their depth and breadth of experience.

 So several paths to get there, but these are the most common.

I want to pursue a career in aeronautics and want to get into NASA. Any advice?

So a lot of the research that we do on board the International Space Station has a relationship to an Earth-based disease.  For example, we worry about bone loss; that's got a relationship to things like osteoporosis on the ground.  All of the things we need to do to keep the human body healthy in a confined environment in the long term we're learning about on the International Space Station.

The things that we do on our six-month missions would build into year-long missions, would build into even longer term missions, for example going to Mars.  So we need to know about things like radiation and the effect on the human body, bone loss, how people are going to be able to work and live together in a confined isolated system for so long.  How we're going to get enough nutrition and getting the right balance of nutrients in a really long duration mission.  And then also, how are we going to keep people healthy?  What kinds of medicines can survive that long in space and how do you treat any illness or injury that occurs?  

So all of these things are actively being researched on board the International Space Station and a lot of them have a component to human health on Earth as well.

How could your research in diseases help missions to the Moon, Mars and other places in our solar system?

On a daily basis?  That's a good question, because when you think of people that might be dressed in flight suits and things or have the duty title of a pilot, that's not all we do.  

Most of our time is actually spent working, coordinating with teams, whether it's scientists with different objectives, learning what they want to do so that we know how to translate that into where we need to put the airplane, to put their instruments in the right place to measure what they want to look at.  Or with engineers, when we're redesigning or modifying aircraft so they can perform the way we want.

That combination there is really pretty amazing.

What do you do on a daily basis?

One of the things I always find to be most fascinating about spaceflight is that I can be on the phone with a crew member who has called me from the space station while watching them fly over.  And every time I always sit there like a dork and go [waves] "Hiiiii!" as if they can see me.

What aspect of spaceflight always blows your mind, even after all this time?

"So a black hole is just pure gravity.  In technical terms, that means that Einstein taught us that gravity is energy.  Energy is mass (E = mc2) .

Mass creates more gravity, so you get this essentially runaway effect where gravity is causing energy is causing mass is causing more gravity.

And it just pulls itself in on itself more and more and more, and you get this runaway called a singularity surrounded by an event horizon, which is the black hole."

uhmm, can you tell me what exactly a black hole is? or what iy does? thanks, just really confused and curious on how it actually works.

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.

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?

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?

“So, I’m a theoretical physicist, so frankly I haven’t discovered anything in my life, but I have made a handful of predictions.  One of those having to do with black holes is-has to do with the way the light gets bent by the black hole–the extreme gravity of the black hole–so you can get light bouncing back and forth across an accretion disk due to the extreme gravity of the black hole. 

NASA is actually working right now on building a new x-ray telescope that can measure this effect, the extreme light bending by the black hole.  So hopefully in the next few years we will be able to make that discovery and prove that prediction correct.”

What is the most interesting fact that you discovered about Black Holes? And what is the one you would most want to find out?