Saturday, November 23, 2013

Astrophysicist Neil deGrasse Tyson and Astronaut Mike Massimino on the film, "Gravity."

Popular astrophysicist Neil deGrasse Tyson,  two-time veteran astronaut Mike Massimino, and comedian Chuck Nice answer listener questions, talk about what it's really like to be in space, and discuss the scientific inaccuracies in the film "Gravity". Gravity, the 3D film by  Alfonso Cuarón, has globally become the highest grossing live action October film of all time. Tyson (quite hilariously) *tweeted about the inaccuracies in the film soon after its release, and caught much more attention for it than he expected. While Both Tyson and Massimino agree that the film got a lot right, Tyson uses his radio show, Star Talk Radio, to address these errors a bit further. Massimino's experiences in space are very instrumental in this discussion, as well as generally interesting.  

To listen to this show,  click here. I paraphrase and provide accurate information given by all parties to allow you to obtain the information faster than listening to the 45 minute show.They also talk fast at times, so reading this allows you to learn at your own speed, especially if not familair with physics.  What I have written is not often an exact transcription of what was stated.

Knowledge Nuggets: 

Tyson stated that there were a dozen or more inaccuracies in the film. Massimino and Tyson agree that the film was well grounded with accuracy; they got a lot of the science right.  Some liberties were taken as expected with a film, but because of how grounded it was, it actually merits being criticized. 

Massimino:  Two thumbs up for capturing the feel of what it's like to be in space. The tools used to repair the Hubble were also accurate.

If in a situation with debris etc, do you save the machine or save yourself?
Massimino: You save the telescope. There are other astronauts up there. Events like a micro-meteor impact are also practiced before you go in space. 

What was the most egregious thing about the movie? 
Massimino : The way they could go from place to place in space so easily with their little jet packs. They had to take some liberties to make the ISS (International Space Station) be right there. Also, for his last trip, there was a shuttle and crew in quarantine ready to rescue them, unlike in the film.   

Tyson: There is gravity in space. Astronauts, satellites, etc. are in orbit between the moon and earth, constantly falling towards earth. He used an example from Isaac Newton, a thought experiment about firing a canon from a mountain top. Fire it slowly and it will soon fall and hit the ground. The faster you fire it, the farther it will go. If you shoot it so fast that it goes all the way around the earth, it will hit you in the back of the head...but if you duck, (it doesn't hit anything), it will continue to orbit. It's going to keep going rather than hitting the ground because curvature of earth. To orbit is to be a continuously falling object, but the planet curves away from it so the object never hits the ground, even though the object tries. To orbit is to be in free fall, and when you're in free fall, you're weightless. 

Massimino: Weightlessness is fun (after the nausea passes). We kinda experience it on earth with some theme park rides or when you're driving and hit a big bump in road where your stomach comes up, or when you're floating in water (not on top) like a scuba diver, that buoyancy. Tyson also added that if you cut the cable on elevator and free fall, you'd be weightless.

Tyson provided a home experiment: puncture two holes in a tall cup, then fill with water. Notice that the hole at the bottom will have more pressure and water will come out farther away from the cup. Now hold the cup high as it spills out and let go of cup. The spigots turn off instantly and the water and cup are weightless. The water is in free fall so it doesn't know to come out.

Are astronauts constantly falling down at 17,500 mph? 
Tyson:  They're falling 17,000 mph sideways, not down, and because they're going so fast sideways, it means they're falling down towards earth at rate that it curves away from them. Also, the shuttle launch doesn't go up into space, most of energy is to give it horizontal speed. This is why the space shuttle rolls. They launch to the East because they pick up speed following earth's orbit.

Is the scene Bullock where uses a fire extinguisher to manuever around, accurate?
Tyson:  If your mass loses mass,  (holding the extinguisher, it becomes part of her mass), the extinguisher pushes mass out, so she must recoil. If she doesn't push the mass out through a line that connects to her her center of mass, she would start to  rotate. You must know how to aim it. He adds that even when you burp, you must recoil. 

Massimino: (on the fire extinguisher scene): She was being smart there. We have a smaller jet pack that shoots gas one way and a hand controller to direct it so you can maneuver and propel yourself.  

Does weightlessness have an affect  on cognitive functions?
Massimino: The brain tries to figure out what's going on. The inner ear/vestibular system tries to figure it out, which takes a couple days. Your brain says your body is still, but your eyes say what position you're in (floating around). As an example,  if you suddenly become weightless right now and you flip upside down, your brain says you're right side up, that the room is upside down, not you. Your orientation is all messed-up. Also, the distribution of your fluids get pooled to the upper extremities, so your head gets big. Your brain then thinks it has more water and you urinate more, giving you a higher risk of dehydration. Drinking lots of water is important, especially while the  body adjusts. None of this messes-up your intelligence.  

How do they not tear their suits sliding all over the place?
Massimino: You have to be very careful in space not to tear your space suit. My space glove tore on a space walk fixing Hubble. There was a weak point between the thumb and index finger as it needs to be a flexible area. The suit is seven thin layer in case it's penetrated with some impact. There's thin kevlar then a pressure layer, though no kevlar in the gloves. The final layer is pressure layer (a bladder). Once that's penetrated you have a pressure leak; your oxygen goes out and the pressure goes up.

How did they enter other spacecraft that should've been internally sealed?
Massimino: The doors open to the inside like an airplane and pressure keeps it locked. You can open the door if there's no pressure on the inside.  If it's a pressurized volume, if you can go in and take space suit off and live, like in the film, that won't work. That door wouldn't open. They took liberties with this in the film.

Tyson: Speaking of pressure, suction cups have nothing to do with suction. If you push a suction cup down and expel the air, there's nothing to balance the air pressure around it so the atmosphere sits on it at  15 lbs per square inch. The larger the suction cup size of course, the more pressure. That's why a suction cup will work on the ceiling or walls; atmospheric pressure works in all directions here at the base of the atmosphere. 

In the fire on the ISS there were small floating fireballs. Is this possible? If fire rises how does it work in zero gravity?
Massimino: We don't know exactly how it would happen as we've never had a real fire in space. Gravity helps fire rage, it's the fuel. A raging fire doesn't seem likely with a lack of fuel. It would just go out. Everything they have in space is also fireproof. We have fire extinguishers for a small localized fire and an electrical fire would be what we  would expect if there were one.

Tyson: In space, a candle will extinguish itself. 

Are they allowed to stay outside (on a space walk) until the reach the last 10% of their  oxygen as in the film?
Massimino: They wouldn't be out with less than an hour of reserve.

If we put a fat astronaut into space, how would their gravity affect earth?
It costs $10,000  per lb to put someone in orbit. Tax payers pay would pay much more, plus extra materials for a larger space suit, clothes, and food.

If you're lost in space, is there a suicide pill?
 Massimino: No 

Massimino, would you rather drift into space until you die or take a suicide pill?
Massimino: I would get every second out of it I could. No pill. 

Is it possible to launch a satellite capable of changing orbital altitudes instead of falling around the earth?
Tyson: Yes, you can change angle, height, altitude and re-enter the atmosphere, but only  if you have fuel.

Do astronauts get trained in breathing techniques to prolong oxygen if in trouble?
Massimino: We always take as shallow breaths as possible. If you take a full breath, you use more oxygen and breath out more c02, which uses-up the filter. 

My thoughts:

Having watched the fabulous film that is "Gravity" (widescreen, 3D, HD...only way to do it) and happening to read Tyson's amusing tweets about ten minutes after they came out, I was especially interested in this show. I could listen to Tyson talk about anything though. Really. Let him give a five hour lecture on today's weather around the world; I'll be captivated. Something about his charisma and manner of speaking just do it for me. So, anyhow, between that and wanting more information on how "real" the film was, he had me at hello with this radio show. I'd already spoken with an astrophysicist friend about it, but Tyson, and especially Massimino, discussed topics that we didn't get to...mostly because I wouldn't have even thought to ask the questions. I learned a lot by listening to this show again and again in order to understand and be able to paraphrase the info!

Also, if you haven't seen HUBBLE 3D  (2010) and get a chance, I recommend it highly. It's an absolutely enthralling documentary, especially in 3D.  I've watched it twice recently at the Smithsonian Air and Space Museum in Washington DC. Massimino was one of the astronauts in the film and easily one of my personal favorites.

Further Reading:

Twitter Feeds:
Neil deGrasse Tyson @neiltyson
Mike Massimino @Astro_Mike 
Chuck Nice @chucknicecomic

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*Below are Tyson's Tweets after seeing the film

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