The “Star Wars” saga isn’t exactly a science textbook, but there’s one fact about the universe that the movies got dazzlingly right: There are more planets out there than you can shake a lightsaber at.
Back in 1977, the movie now known as “Star Wars: A New Hope” put an assortment of alien worlds on display. There was Tatooine, a desert planet with two suns. Alderaan was Princess Leia’s home planet and the epicenter for a “disturbance in the Force.” Rebels took refuge on a moon in orbit around the gas giant Yavin.
In those days, the idea that there could be so many livable worlds seemed like pure science fiction. “For the most part, scientists thought planets were very rare in the universe,” said Jeanne Cavelos, an astrophysicist-turned-author who literally wrote the book on “The Science of Star Wars.”
Now we know better. The first planets beyond our solar system were discovered in 1992, halfway between “Return of the Jedi” and “The Phantom Menace.” Since then, more than 1,000 exoplanets have been added to the list. And if that figure doesn’t wow you, observations by NASA’s Kepler space telescope suggest there are billions of habitable planets in our Milky Way galaxy.
Some planets are known to orbit two suns, just like Tatooine. There are also lava planets (like Mustafar in “Revenge of the Sith”), cloud planets (like Bespin, home of Cloud City in “The Empire Strikes Back”), disintegrating planets (like Alderaan), frozen planets (like Hoth) and perhaps ocean planets (like Kamino in “Attack of the Clones”).
Astronomers even think it’s likely that some moons of gas giants may be habitable (like Yavin in “New Hope” and Endor in “Return of the Jedi.”)
The planetary plenitude earns the “Star Wars” saga an A-plus on its science report card. Other aspects might not score as high. But you do have to remember: “Star Wars” is only a science-fiction movie.
Kevin Grazier, a planetary scientist who’s the co-author of “Hollyweird Science: From Quantum Quirks to the Multiverse,” won’t even go that far. “I wouldn’t consider it science fiction,” Grazier said. “I consider it fantasy. It’s on par with the superhero films.”
For that reason, Grazier doesn’t get uptight about X-wing fighters that make zooming sounds in the vacuum of outer space. And neither should we. With that in mind, here are four flights of fantasy from past “Star Wars” films and how they compare with 21st-century realities:
3-D augmented reality
“Help me, Obi-wan Kenobi. You’re my only hope.” The 3-D projection of Princess Leia would be child’s play if Luke and Obi-wan were plugged into their HoloLens headsets. “Augmented reality” wasn’t even a thing back in 1977. Now AR technology – which involves projecting computer-generated 3-D imagery over your field of view – is all the rage. They’re even doing it on the International Space Station. Grade: B.
If you’re Han Solo and you need to make the Kessel Run in the minimum number of parsecs, it helps to jump to hyperspace. Being able to take an extradimensional route from point A to point B at a faster-than-light velocity also helps move a movie’s plot along, whether it’s “Star Wars,” “Contact” or “Interstellar.” The concept is theoretically possible, if Han Solo is able to traverse a wormhole.
“One problem is, wormholes are believed to be much smaller than atoms, so it would be hard for Han Solo to fit through one of those,” Cavelos said. It would take some sort of exotic matter, perhaps dark matter plus dark energy, to widen a wormhole and keep it open. Grade: C.
First there was the classic lightsaber with just one blazing blade, color-coded for the good guys and the bad guys. As the movies progressed, the lightsabers became more baroque. In “The Force Awakens,” Kylo Ren wields a weapon that’s lit up like a Christmas tree.
Fermilab physicist Don Lincoln says the closest thing to a lightsaber that you could make in real life would be a plasma weapon contained by magnetic fields. Plasma could pose problems, however: Cavelos says physicists have told her the plasma temperature would have to reach 200 million degrees. Even if it could be contained, there’s a risk that some of the hot gas would leak out from the top and bottom of the lightsaber, incinerating anything in its path.
“You might be better off just mailing a lightsaber to your enemy,” Cavelos said. “He opens the package, turns it on, and gets horrible burns all over his body.” Grade: D.
In the first “Star Wars” movies, the Force was a mystical energy field that needed no further explanation. But when “Phantom Menace” came out, it turned out that the Force was channeled through midi-chlorians – microscopic, intelligent life forms that were present in all living cells. A blood test could determine how high your midi-chlorian count was. The higher the count, the more the Force was with you.
For some fans, this pseudo-scientific claptrap was a bigger buzzkill than Jar Jar Binks. J.J. Abrams, the director of “The Force Awakens,” promised that there’d be no midi-chlorians mentioned in the new film. The funny thing is that we really do have little critters in our cells that help channel the life force. It’s just that they’re called mitochondria, not midi-chlorians.
Grazier argues that midi-chlorians have gotten a bit of a bad rap. If you’re charitable about it, you can think of midi-chlorians as being linked to the Force in the same way that Higgs bosons are linked to the Higgs field.
“If you look at the physical definition of a ‘force field,’ the Force as created by midi-chlorians comes closer to that definition than what we typically see as an impenetrable barrier created by technology to keep the good guys in or the bad guys out,” Grazier said.
Grazier points out that the invisible force fields typically depicted in the movies don’t exist, either. But they might someday, if Boeing follows through on a patent application. Grade: F (for the Force)