With a blare of Imperial trumpets and the now-familiar march of words across the screen, "Star Wars: The Last Jedi" blasted its way into theaters across the country this weekend.
While the jury is still out on where the film ranks in the "Star Wars" pantheon, there is no denying the mark this movie franchise has had on society. (Note: there are no spoilers here.)
The "Star Wars" movies have never really been about science or technology. They focus more on spiritual issues and the storyline of a family seemingly destined to guide the fate of the galaxy. But the films are in the genre of science fiction and that means that scientists like myself can't help asking whether the science and tech we see on the screen are even remotely possible.
Let's take a look at some of them.
Droids, short for androids, are one of the more plausible technologies in the "Star Wars" universe. Current robotic technology is used mostly in industrial applications (with significant consequences for our economy, although that is another story). However, in "Star Wars," robots are not just industrial drones. Starting with the iconic C-3PO and R2-D2, and now joined by the personable BB-8, these robots have personalities and capabilities that differ little from people.
Reality check: Yep, definitely going to happen.
There is perhaps nothing more iconic in the "Star Wars" franchise than the lightsaber. Heroic Jedis cut their way through a swath of robots, Stormtroopers and the occasional Sith Lord in a dazzling display of colorful swordplay.
There has been much written on how the lightsaber might work, with some real attention to the required technology. From "The Phantom Menace," we can deduce that the Jedi's lightsaber must wield at least 20 megawatts of power, which is about the energy needed to run approximately 14,000 American households, all stored in a device small enough to be held in the human hand. There are no known energy sources with that kind of capability, except perhaps antimatter. Even nuclear power won't work.
By ignoring this energy problem, various technologies have been suggested for how a lightsaber might work, but most center on the possibility that they are plasmas with perhaps a ceramic core. Then there is the issue of why the immense heat of these plasmas do not char the hands of the Jedis. All in all, the lightsabers and the possible technical solutions raise more questions than they solve.
Reality check: Sorry, Luke, Han was right when he said ancient weapons are no match for a good blaster.
Faster than light travel
"Star Wars" began with a story about the conflict between a rebellious group and an empire that spans a galaxy. And to have a galactic empire means that you need to be able to travel great distances in a reasonable amount of time.
We can take our own Milky Way galaxy as a baseline. It has a diameter of 100,000 light-years, which means that it would take a beam of light 100,000 years to cross it, and half of that to fly from the center to the edge.
There are reasons to believe that the galactic center would not be hospitable to technological civilizations. This is because of the proximity of stars and the dangers of radiation from nearby supernovas. So maybe the Empire "only" spans a few tens of thousands of light-years.
But even that smaller volume is immense. Traversing these sort of distances in a reasonable time will take a new discovery, like the hyperdrive of "Star Wars." Nominally, this involves spaceships moving through alternate dimensions of space and time to get to their destination. Unfortunately, there is absolutely no evidence of dimensions of this kind, and they probably don't exist.
Reality check: Not very likely, even if you live as long as Yoda.
Even people who have never watched "Star Wars" have probably heard the phrase, "May the Force be with you." The Force is said to be an energy field that permeates the universe.
According to the "Star Wars" canon, people contain within their cells intelligent organisms called midi-chlorians. People with more midi-chlorians can harness the Force to perform superhuman feats, such as telekinesis (using the mind to manipulate objects) and being able to anticipate the intents and motions of a foe.
Setting aside the fact that there have never been reproducible reports of telekinesis, there are some real physics issues here. For instance, when an object is lifted by any familiar way -- say, when you or I pick up a ball -- the forces must balance, meaning that as you pick up a ball your weight increases. But when you see a master of the Force such as Yoda or Darth Vader lift a heavy object, there is no transfer of the weight anywhere.
Reality check: Unfortunately, it is very unlikely that the Force will be with you.
Death Star/Starkiller Base
In the original "Star Wars" trilogy, two different moon-sized battle stations called Death Stars were said to have the power to destroy a planet. And in 2015's "Star Wars: The Force Awakens," a mobile ice planet called Starkiller Base could destroy several planetary systems across the galaxy in a single shot.
Are those possible?
You can calculate the energy needed for a Death Star to destroy a planet. To destroy the Earth, you'd have to harness the energy output of our Sun for an entire week. That's already challenging, but the Starkiller Base drained the entire energy stored within a star, which is typically emitted over billions of years. Either way, this is a ton of energy to control, but the second one is especially hard to imagine. Somehow Starkiller base absorbed and stored the energy of a star in a location on a planet.
Reality check: No way. That's just crazy talk!
Now, to be fair, we don't watch movies like "Star Wars" to be educated about science or space. We watch them to have a good time, and "The Last Jedi" is the latest in a franchise that has entertained a generation of moviegoers and their children for four decades.
So, don't sweat the science. Grab some popcorn, sit back and enjoy the spectacle.
And may the Force be with you.