The Science of Avatar (Part II)

By Sheril Kirshenbaum | December 29, 2009 11:16 am

After watching Avatar last weekend, I composed a post about being particularly appreciative that James Cameron and his crew so obviously did their homework when it came to much of the science depicted onscreen. I invited readers to share their impressions and many of you came through with terrific examples–some I hadn’t even considered before. So I’ll run through five of the science details I enjoyed most, followed by a few of the best examples from our reader community:

1) Dr. Grace Augustine. Sigourney Weaver’s portrayal of a research scientist was uncharacteristically good. Instead of the typical caricature we see in Hollywood, she wasn’t socially inept (i.e. typical Rick Moranis roles) or out to destroy everything (i.e. Dr. Evil). Instead, Grace conveyed the natural curiosity about the world that I observe so often in colleagues. Also noteworthy, she was funded by a program with corporate interests, but really using the opportunity to pursue her own research. Sound familiar to anyone?

2) The Skull. Did you catch the Toruk skull? It wasn’t onscreen long, but it appeared to have characteristics of both birds and reptiles. I couldn’t tell for sure, but it seemed quite detailed and cool.

3) Bioluminescence. With a background in marine biology, you know I’m going to appreciate that.

4) Scale. If gravity on Pandora is less than that on Earth, larger organisms would be supported.

5) Location. The choice of putting Pandora on a moon in the real Alpha Centauri star system (the closest system to Earth) was neat since scientists are looking at moons for life. The radiation anticipated could be mitigated by superconductivity. Which brings me to…

Those floating mountains. Many comments expressed disappointment with them, however, it’s not quite as implausible as you may suspect. The filmmakers put thought into this: Superconductors expel magnetic field lines, so the effect could make these mountains levitate like magnets away from the surface. (Details here).

Picture 5

There is a great deal more I like about the science of Avatar, but rather than compose an exhaustive list, I’ll quote some examples contributed by readers below the fold…

Phenomenal writes:

Enjoyed the fact it was a moon, different gravity & atosperic composition, the scientists passion for knowledge & care & respect, transduction between plants, several different layers to the food web, imaginative topography such as floating mountains & giant trees, Gaia theory, biomechanics of the creatures locomotion as six-limbed vertebrates, biolumeniscence & colourations of the flora & fauna.

Patrick B. writes:

..great thought went into the physics of the Pandora solar system, to the geology of the planet, to the plants and animals that evolved on the planet, and to the social structures of the Na’Vi.

1- Pandora appears to be a moon orbiting a gas giant. The gas giant can be seen in the sky in several shots in the movie, and you get the sense that the proportions are realistic.

2- Pandora’s atmosphere is not breathable to humans. I loved this! In Star Wars, Star Trek, and just about any other sci-fi film, there are countless planets with human-breathable air, which is not very realistic. The air pressure on Pandora is tolerable for humans, but humans need face masks in order to breath. It seems that the face masks somehow modify the Pandora air, perhaps by filtering out the bad gases.

3- One line in the movie establishes that Pandora’s gravity is slightly less than Earth’s. By adding this line, the film provides sufficient explanation for why Pandora has phenomenon like gigantic trees.

4- There was clearly a great deal of thought put into the diverse plants and animals we find on Pandora.

The Real World writes:

This article is nothing more than an advertisement in a media science magazine.

Huh? This is a blog TRW and I work at Duke.

Lee writes:

I thought it was cool that you could see an evolutionary resemblance between a lot of the creatures. Everything except the humanoids and the rest of the animals, that is. If everything else on the world has six legs (or wings, or whatever), then why would the humanoids only have four limbs? What possible evolutionary advantage could they have for losing them?

Marshall P. writes:

sub-lightspeed space travel! After I left the theater, I was explaining to one of my friends that based on the stated travel time by the cryosleep doctor, and the distance to Alpha Cen, one could work out the ship’s velocity profile consistent with relativity. And few hours later at home, I stumbled upon the web page by the movie staff where they lay out exactly that!
Someone did their homework on this one. Even the propulsion technology of the ship is quite plausible, given the just one highly speculative step of being able to manufacture large quantities of antimatter for fuel. I especially like the hybrid antimatter/fusion rocket combined with a beam-powered light sail. That’s exactly the sort of complicated trick that real-world engineers would use to reduce fuel and mass constraints on the spacecraft.

kchiou writes:

1) Despite their futuristic tools and their corporate ties, the scientists maintain a childlike curiosity and sheer bewilderment with nature. As a field scientist, that depiction really resonated with me because I see it all the time in the faces of field researchers. Just a thought: do you think Sigourney Weaver’s performance as a scientist was in any way affected by her work on Planet Earth?

2) As an extension of the first point, the scientists are conscious of the sheer wealth of knowledge in the Pandoran ecosystem and are careful not to presume too much. This is much more in line with true science. The way that Sigourney Weaver’s character said “What we THINK we know is . . . ” can be pulled right out of any science lab.

Gary Thomas writes:

I found it very annoying that they got the sound of the ducted fan aircraft so wrong. The whoop whoop sound of a large slow speed rotor on a helicopter is not the sound that counter rotating blades, especially small diameter ducted ones would make.

I don’t know about ducted fan aircrafts, but an interesting observation.

Rich writes:

The floating mountains were very clearly explained in the movie. They even show the unobtainium superconductor floating in a magnetic field several times in the human base, and then there are multiple lines of dialogue about the mountains being in a region of strong magnetic field. It does make me wonder why they aren’t mining the mountains though…Also, it’s refreshing that the scientists are the good guys in the film!

Great work so far everyone, and add any new observations in comments…

CATEGORIZED UNDER: Culture, Media and Science

Comments (41)

  1. Jason

    Would much rather have my kids getting their science fiction from this movie than from Star Wars or Star Trek. After all, it comprised both good science and great messages. Would have seen it again, but bad weather in the midwest has kept me out of the theatres.

  2. Joel Barkan

    To continue on the bioluminescence theme, I’d like to point out a specific element of the glowing jungle that the marine biologist in me particularly enjoyed. The forest floor appeared to be carpeted with what looked like a close cousin to the sea pansy, one of my favorite marine species. The sea pansy is a cnidarian (related to anemones and jellies) that resembles a flat mushroom cap. When provoked, it can sustain its light for several seconds, as opposed to the quick flash produced by most planktonic organisms. While walking through the forest at night, Jake and Neytiri repeatedly step on the Pandoran pansies and leave a trail of glowing muffin tops behind them.

    Cameron has claimed he made the blockbuster Titanic in large part to fund his expensive hobby of deep sea exploration. He made a very good 3D IMAX film about the deep sea that I saw a few years ago at the Smithsonian. With that film in mind, I viewed Avatar on the lookout for oceanographic references and noticed quite a few throughout the movie.

    The next step for Cameron (at least on my wish list): a sci-fi film produced with Avatar’s 3D technology that takes place entirely underwater. I’m not sure I’d be able to handle it.

  3. Pete

    The skull looked impressive. I agree.

  4. Marci

    I thought it was interesting how Weaver’s character played multiples roles as a laboratory and field scientist, as well as playing an anthropologist/peacemaker/schoolteacher. I guess you wouldn’t want too many different scientists on screen, but that’s quite a lot for one person to handle. I think you could relate this to the double work day of women, whereas Sully just gets to run around in the jungle and sleep.

  5. I thought it was interesting how Weaver’s character played multiples roles as a laboratory and field scientist, as well as playing an anthropologist/peacemaker/schoolteacher.

    I liked that. Most every professor I know juggles a myriad of responsibilities from teaching and advising to research and review. Again, a very good portrayal of an academic career.

  6. Tetsuo

    And everybody is born with an USB interface built-in! How cool is that?

  7. Michael

    In one of the first shots of the floating mountains, I saw the rock formations below them. At first I thought they were just regular arches, and then I realized that they were loops … similar to coronal loops that result from solar magnetic flux. I knew why the mountains were supposed to be floating. I don’t know if any of it is actually plausible, but I applaud them for putting so much thought into the details.

  8. Matt

    Since most of the posts are dealing with the bio-side of things, how about the mechanical? I agree with Gary Thomas’ gripe about the sound of the ducted fans, though to a point. The counter-rotating props (two pairs in each ducted fan – 4 total props in each fan) were very close together, meaning the proximity of the counter-rotating props could be the explanation. Also, the depth of the *duct* was minimal, which poses another possible explanation.

    The way that the ducts were articulated showed a clear understanding of the mechanics of flight. They were constantly adjusting their angles, thus altering the direction of the thrust. Not surprising since Cameron is a heli pilot.

    I thought that it was clever that the shuttle used for the bombing run was the only vehicle that resembled a re-entry vehicle.

  9. Yeah, the concepts in this movie made me so happy. I mean, what an awesome reinvention of what is essentially a dragon! Microraptor gui and sunset moths with dragonfly and predatory fish adaptations! That’s right up my alley! If you look at how each creature functions, they really did a great job looking at an alternate evolution for sea life without just putting giant, oddly colored versions of common animals in. I cant wait for my order of the natural history book and art book come in! As someone who specializes in concept and worldbuilding…this movie rocked. I dug the plot also- to me it read like an old legend. Cant wait for a sequel.

  10. J. D. Mack

    With all of these explanations for the floating mountains, I wonder what’s next, “The Science of Roger Dean Album Covers”?

  11. Dave C

    I really loved this movie, and more than anything else, felt like I wanted to explore the ecology of the entire planet. Obviously, the ability of different organisms to “plug” directly into each other and exchange information via their pseudo-USP ports would have great ecological implications. Many of these implications were explored, but I could definitely handle learning a lot more. I really hope that James Cameron chooses to make more movies set on Pandora–though they wouldn’t necessarily need to be direct sequels to “Avatar.”

  12. JC

    To the person noting Weaver’s character holding down too many job titles:

    I find the characterization rather plausible. In any skeleton crew situation, people end up with more job titles than they’d ever want. The lab geek has to be a field researcher if she wants the goods.

    I would also assume that an era like this, where people are out of contact with the mainstream of their civilization for years on end, would be similar to previous such eras. If a would-be scientist in the early 1800s wanted to go out into the world, they got stuck half-assing all the other roles that other, better scientists would fill. Most discoveries during that era were filtered in a slow cycle through the major European cities as scientists would return with their specimens and their stories.

    You’re not going to get a lot of scientists to spend 6 years in cryo, followed by however many years wandering around an inhospitable planet, followed by another 6 years in cryo. So, the person directing the avatar program is also going to get stuck being the anthropologist. It’s just how small, far-off-the-grid operations work.

  13. Guy

    I think James Cameron and his crew did a good job with the science for the most part. Given the amount of time and money spent on making Avatar it’s difficult to imagine what more they could have done to make it seem more realistic. About the only thing that jumped out at me was what evolutionary forces would have created the Na’vi. They don’t resemble any of the other creatures so their evolutionary history is unknown. Maybe they can address that in some future sequel .

  14. One of the few things I didn’t like was the name of the stuff they were after: “unobtainium”. That just seemed silly, and out of place with the effort that went into realism everywhere else.

    I agree that the bioluminescence was cool (and beautiful), but I’m not sure I understand why practically everything either lights up or glows. What’s the evolutionary advantage in that?

    And how did the floating thingie know that Jake is “good” and prevent Neytiri from killing him early on? This smacks of some sort of ESP, which makes me very nervous.

    But these are nits. Overall, the science behind it all was very well thought out. It’s good to see; sci-fi movies generally can’t be bothered with it.

  15. I loved the easter eggs for people who care. In one of the split-second close-ups of the ikran skull, I thought, “Huh – jaw looks a bit fish-like”. The next day, I find this Wiki created by the creators, which says “shape of jaw indicates that Ikran may have evolved from fish”. That’s just earned them more of my money.

  16. I liked that Weaver’s character is a smoker – which is more humane than the portrayal we usually think of – but I didn’t like that she smoked inside the lab (specially using her assistant to further her non-academic needs).
    It’s interesting to notice how the traitor took advantage of the natives’ gullibility in his return – by riding the ikran all his wrongs were automatically forgiven by the na’vi. This tells us more about the bon sauvage than the rest of the story.

  17. Guy

    @Chris #15,

    How do you know that there isn’t some biological form of ESP? If all life on Pandora is connected, then they would have a sensory net that far exceeds anything else. It could be that the life on Pandora was just a good judge of character and acted to protect what it liked.

    With movies, you have to suspend disbelief to some degree. Most people love Star Wars but had to just accept the idea of the force and Jedi powers as being part of the fiction. Course, you could say that Lucas merged fantasy with sci-fi but still it’s a matter of perception.

  18. Marci

    So perhaps as an undergrad I’ve underestimated the work “real” academics do 🙂

    Nonetheless I’m still a little perturbed that the role of women as both caretakers and hyper-achieving scientists is naturalized as perfectly realistic, while men mostly play one role (or at least one role at a time).

  19. phil

    The neural connections that most creatures had excited my imagination. If most animals had it, then it must have been A: an evolutionary advantage, and B: a trait found in a common ancestor. It seems to make the most sense for animals like the dire horse, a herbivore that presumable travels in packs, and could benefit from instantaneous communication. For a solitary hunter like the thanator, it makes less sense, unless it serves a benefit in keeping a mate or raising offspring. Of course, if any animal can use it to communicate with nature, then it could be very useful indeed in locating prey etc.
    The navi apparently find such a connection very useful, but don’t appear to use it with another, even between mates. My reasoning would be that perhaps it is taboo. It could result in one person taking control over another permanently, like with the flying animals, or a sharing of too much information. Thoughts?

  20. Jon

    I’ve been wondering that since I saw the movie, Phil. How could they resist hooking together when they were actually having sex? Maybe it’s not a taboo, maybe it’s just lousy making love that way.

  21. Martin

    Well, when I saw the movie I was wondering how it was possible that the native population of Pandora had evolved to look and behave pretty much exactly as humans. They even had the same expressions of emotions, like laughing and crying. This was extremly unscientific and suggested some kind of intelligent designer. There´s no way two different species would just happend to be this much alike.

  22. Phenomenal

    Thanks for pointing out the details about the skull. That was something I missed entirely and delighted to read about that fits in conjunction with the tropical fish colourations.

    James Cameron is recently quoted as suggesting that the “USB-connection” appendage physiology that appears common to all fauna on Pandora, is how the Na’vi actually mate and may be included as an extended extra in the dvd version, of the scene where this happens. This appears to be coherent to with other sea denizens such as how Cuttlefish mate, using a tentacle-like medium to transfer gametes, between sexes . In fact, perhaps this is a common-inherited “bauplan” of the reproductive system on Pandora? Albeit the Na’vi appear to have done a typical evolutionary-trick and extended it’s original function?

    Wow, a ton of guesses! Hope people can fill on the other science. The reading about the heli-rotars, space travel & magnetic fields was very fascinating. Good piece on the linguistic choices below:

  23. Phenomenal

    @ Martin #22 & Guy #15: quote: Unquote: “Unknown evolutionary history” & “suggests intelligent design: Well appears two options: Either Convergent evolution &/or some common ancestor! It looked like the avatar’s have 4 fingers & the Na’vi 3, excluding thumbs? But the major difference between the races appeared closer to differences between 21stC cultures & indigenous neolithic societies is the main emphasis of contrast as well as the biology, which is a strong theme of the movie (land grabbing & qualitative values). But the suggestion DNA between the 2 species can be mixed (creating the avatars) tends towards a common link?!

  24. Phenomenal,0,5033714.story

    “Inventing the Plants of Pandora” – interview with USC Riverside Plant Physiologist, Jodie Holt.

  25. gillt

    I was excited to see the movie and felt the 11.75 ticket price was worth it. Isn’t it enough to say what the movie lacked in story it more than made up for in eye candy and call it a day?

    That the movie took cues from nature doesn’t make the film scientifically accurate just, maybe, more visually believable than most other movies.

    I did think Weaver’s line about wanting to collect samples as her last wish was pretty funny.

  26. To those wondering about if the Na’vi use those things during mating, they might find out when the special “unrated” version comes out on DVD:

  27. As cool as they are, they could have explained the floating mountains. And yeah, how does them glowing help at all?

  28. Did anybody notice that sigourney’s avatar nose was more human? when I noticed that, it almost seemed to imply that her own avatar was maybe a different, or older blend of DNA? version 1.0, if you will?

  29. Phenomenal

    A section of the movie that shocked & surprised me a great deal was “the shooting of arrows as the ‘copters moved in to attack the hometree. I was taken aback at how indigenous they came across. Obviously aware of this theme but it was painfull “real” for me and recalled some stories of the toils and tribulations of tribal people across the world eg Survival charity helps these people.

    But look at this link to the battle between Chevron and: NO HOLLYWOOD HAPPY ENDING

    Quote: “In Peru, President Alan Garcia has called indigenous people “confused savages”, “barbaric”, “second-class citizens”, “criminals”, and “ignorant”. He has even compared tribal groups to the nation’s infamous terrorists, the Shining Path.

    There is no end in sight in the struggle between the indigenous people of Peru and government-sanctioned corporate power. ”

  30. Phenomenal

    Will interest anyone cocerning the linguistics of this language!

  31. you call this science?

    Really, I just want to know why the Na’vi lack rectums. And why do the women have nipples only when they’re outside of close focus?

    And more importantly, what happens when the corporation returns in 12 years and razes the planet?

  32. Mark

    I thought this movie was all in all pretty good, but one thing kept bugging me. Please correct me if I’m wrong. My understanding is that our moon rotates around our Earth but does not spin on it’s own axis, so the same side of the moon faces Earth all the time. So if this is the case with our moon, how is there day and night on Pandora if it itself is a moon. I mean shouldn’t it not spin on its own axis like our moon, but instead just rotate around the gas giant with the same side always facing it?

  33. Phenomenal

    Inspirations for the floating mountains from real life rock formations and mountains around the world + various design interviews:

    @ Mark: Agree, this puzzles me until the exact details of the orbit are expounded. James Cameron is fully aware of this detail however, hence the biolumenescent evolution of the plants during long nights. The system is created in Alpha Centauri which has 3 types of stars and the fictional planet Polyphemus has a number of moons, including Pandora which itself is made of a lot of the strange material Unobtanium.

  34. Tynesha

    I’m not as into the Sciences as most of you guys but I also thought to myself that a great deal of thought went into this movie. The most touching part for me though, was the way in which they became one with eachother and the animals and the plants and such. I thought is was beautiful!!! Especially when they bonded with the animals and how the Toruk would only fly with that person whome they first became one with. there were so many innuendoes and hidden messages in this movie. I loved every minute of it!!

  35. Ed

    Mark wrote: “My understanding is that our moon rotates around our Earth but does not spin on it’s own axis, so the same side of the moon faces Earth all the time.”

    Actually the moon does spin, what happens is that “it rotates about its axis in about the same time it takes to orbit the Earth. This results in it keeping nearly the same face turned towards the Earth at all times.” (I just took it from Wikipedia…)


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About Sheril Kirshenbaum

Sheril Kirshenbaum is a research scientist with the Webber Energy Group at the University of Texas at Austin's Center for International Energy and Environmental Policy where she works on projects to enhance public understanding of energy issues as they relate to food, oceans, and culture. She is involved in conservation initiatives across levels of government, working to improve communication between scientists, policymakers, and the public. Sheril is the author of The Science of Kissing, which explores one of humanity's fondest pastimes. She also co-authored Unscientific America: How Scientific Illiteracy Threatens Our Future with Chris Mooney, chosen by Library Journal as one of the Best Sci-Tech Books of 2009 and named by President Obama's science advisor John Holdren as his top recommended read. Sheril contributes to popular publications including Newsweek, The Washington Post, Discover Magazine, and The Nation, frequently covering topics that bridge science and society from climate change to genetically modified foods. Her writing is featured in the anthology The Best American Science Writing 2010. In 2006 Sheril served as a legislative Knauss science fellow on Capitol Hill with Senator Bill Nelson (D-FL) where she was involved in energy, climate, and ocean policy. She also has experience working on pop radio and her work has been published in Science, Fisheries Bulletin, Oecologia, and Issues in Science and Technology. In 2007, she helped to found Science Debate; an initiative encouraging candidates to debate science research and innovation issues on the campaign trail. Previously, Sheril was a research associate at Duke University's Nicholas School of the Environment and has served as a Fellow with the Center for Biodiversity and Conservation at the American Museum of Natural History and as a Howard Hughes Research Fellow. She has contributed reports to The Nature Conservancy and provided assistance on international protected area projects. Sheril serves as a science advisor to NPR's Science Friday and its nonprofit partner, Science Friday Initiative. She also serves on the program committee for the annual meeting of the American Association for the Advancement of Science (AAAS). She speaks regularly around the country to audiences at universities, federal agencies, and museums and has been a guest on such programs as The Today Show and The Daily Rundown on MSNBC. Sheril is a graduate of Tufts University and holds two masters of science degrees in marine biology and marine policy from the University of Maine. She co-hosts The Intersection on Discover blogs with Chris Mooney and has contributed to DeSmogBlog, Talking Science, Wired Science and Seed. She was born in Suffern, New York and is also a musician. Sheril lives in Austin, Texas with her husband David Lowry.Interested in booking Sheril Kirshenbaum to speak at your next event? Contact Hachette Speakers Bureau 866.376.6591 info@hachettespeakersbureau.comFor more information, visit her website or email Sheril at


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