A Ciência de Avatar

Já colocamos aqui vários artigos sobre o Avatar. Leiam esta categoria.

Achei interessante o número de artigos online que analisam o filme de um ponto de vista científico:
– Popular Mechanics.
– Space.Com
– Discovery News.
– Discovery Magazine: 1, 2.
– MSNBC.
– filmes.

Gostei também das críticas feitas pelo professor John Kormendy a este filme (e que reproduzo aqui com a autorização dele):

“The above image from the movie Avatar shows the moon Pandora and its parent giant planet.
One of the things that the movie did correctly was to use our new knowledge that giant planets are observed at all radii around their parent stars, including radii that would put their moons within the habitable zone of their star.
Since such planets are now known to be common and since we expect that they will in general have moons, such moons are now thought to be the most likely places outside the Solar System in which we may find life.”

“The “mistake” in the picture of Pandora and its parent, giant planet is this: the giant planet is rendered in deep blue colors, like the colors of Uranus and Neptune in our Solar System.
The parent planet clearly is a giant planet like Jupiter, with storms and other cloud features correctly shown. Pandora is one of its moons, as correctly described in the movie.
The problem is this: Pandora and its parent planet are very much in the habitable zone around the star. The temperature on Pandora is comfortably warm. This is OK: it is to be expected that some Jupiter-sized planets will have migrated inward into the habitable zones around their stars. Then their satellites will be plausible places to look for life, and Pandora is portrayed as such a world. All OK. But this means that the temperatures on the giant planet will be warm, too, warmer, in fact, than on Jupiter. The blue color of Uranus and Neptune is created by methane absorption in the atmosphere. But methane would be very abundant only at the low temperatures found far out from the star, way beyond the habitable zone.
The composition of such a giant planet is not much in doubt, and there is no trick to change the composition to favor blue colors. So the planet should be colored more or less like Jupiter or even redder.”

“Arguably, it should also have a stormier surface than is shown.”

“I am not criticizing the movie or its producer, James Cameron. I have the highest respect for James Cameron’s artistic vision and professional skills. I like the movie a lot. It is even possible that Cameron knew very well that the blue color of the primary planet was at odds with the science, but picked it anyway for artistic reasons – he may have done this on purpose. It does create an atmosphere where Pandora is more emphatically emphasized.
A redder, more stormy giant planet would take attention away from Pandora and might look ominous or threatening. Cameron may have deliberately decided to avoid this. With a blue primary, the atmosphere of the picture is calm and serene; maybe that’s what he wanted.”

Notem que podem ler a tradução destas palavras para português, através da tradução automática do Google (com várias falhas na tradução), aqui.