[Warning: Spoilers! If you have any intention of seeing the movie “Gravity,” please stop reading now. If you don’t intend to see the movie, I still urge you to stop reading, and change your mind, and see the movie. It’s really good!]

“Gravity” has many virtues, ranging from the beguiling special effects to the winning performances by Sandra Bullock and George Clooney. The movie is, in its totality, an affirmation of life – not just in the usual Hollywood formula, but in the subtle references to key concepts in biology, evolution and the origin of life on Earth. I think the movie is more scientifically accurate in its biology than in its orbital dynamics. You could argue it’s more of a biology movie than a space movie. (“Could argue” is a useful rhetorical tool that lets us countenance things that aren’t actually true.)

As a space movie, it’s fun but implausible. The movie is apparently set in the near future, where, somehow, a space shuttle is in orbit (having escaped from a museum?), and the Hubble is being repaired again (so much for my Post stories on the “final” Hubble repair mission). We see George Clooney as the ultimate Right Stuff astronaut, skylarking around the shuttle, performing a “spacewalk” with no tether, the whole thing improbably dangerous but visually nifty. In real life, spacewalks are delicate affairs performed at roughly the speed that vegetation grows. There are stoppages in the action for “glove checks.” Astronauts stay clear of sharp corners and edges and pinch points. See our story on the ISS, which includes the narrative of a real-life spacewalking drama that almost took the life of astronaut Luca Parmitano. In “Gravity,” however, the astronauts romp around like Romanian gymnasts, turning space vehicles into jungle gyms.

In Hollywood’s version of space, a cloud of space debris can somehow remain in a geosynchronous Low Earth Orbit such that astronauts at the same altitude and circling the planet every 90 minutes will re-encounter the debris every 90 minutes. I’m pretty sure that’s gravitationally absurd. The movie has multiple violations of the principles of angular momentum. Horrors! [Here’s a blog that goes into all the scientifically implausible stuff.]

There are a number of quotations of other space movies (Ed Harris, from “Apollo 13,” is again the voice of Mission Control), but there are also quotations from the biology textbooks. We see Dr. Ryan Stone (Bullock) repeatedly molting: She peels away the exoskeleton of her EVA suit, assuming an almost larval form. When she finally reaches the pressurized interior of the space station, and discards her space suit, she is seen floating, fetus-like, in a high-tech womb.

Dr. Stone has endured a personal tragedy and remains grief-stricken: Down on the surface, she goes to work, then spends her evenings driving randomly, listening to the radio. In space, she’s pretty much the same: She does her duty, and receives radio communication in her helmet, but is joyless, and the great vacuum of space speaks to a painful emptiness in her life. So this is a movie about a woman who needs to learn to live again.

The secret to life is the desire, the compulsion, to be alive. Dr. Stone needs to find some way to move on, to put her feet on the ground – again — and stand up, and live in the light of day. The whole space thing is a gimmick for telling that story.

Which brings us to final, powerful scene. The flaming debris that bombards the surface brings to mind the early Earth, and the Late Heavy Bombardment of space rocks, which, scientists tell us, gave way to a period of relative calm in which life emerged (going back 3.8 billion years or so, to when I started at The Post). We see a second molting underwater (a frog swims by, a nod to the amphibeous nature of early life). The tidal lagoon in that final scene is straight from Darwin’s theory of the origin of life and the “warm little pond.” See his letter to Joseph Hooker.

The landscape is primeval. There are no trees, no flowers, no people, no animals, just a kind of bland greenery on mysterious, anonymous hills. This is the world as it was hundreds of millions of years ago. Life crawls from the sea, and learns to live on solid ground. Space is fascinating but biology moreso. The Earth itself is a spaceship, somehow able to be habitable for all these billions of years, giving rise to simple bacteria, galloping animals, flying creatures, and one biped that figured out how to make really cool space movies.

[FYI, I’m in California working on my space project. Here’s the splash page of our “Destination Unknown" series.]