Physics of Star Wars book explores the science of The Force (and Gungans)

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Sep 5, 2017

Whether it’s a lightsaber or hyperspace travel, Star Wars teases the tantalizing and impossible. As we continue to make scientific and technological advances it’s hard not to wonder: how close are we to these things ever truly becoming a reality? Professor Patrick Johnson of Georgetown University puts some science into the science fiction in his upcoming book The Physics of Star Wars.

The book is broken into nine sections, exploring a different broad area of the Star Wars universe, and then subtopics within those categories. For example, the "Space Travel" section has chapters with topics like "Solar Sails," "Hyperspace," and "Ship Design." Each chapter offers an introduction to the topic, backstory about its place in Star Wars, how it works with the physics of Star Wars, and then a look at it within the physics of the real world. One section of the book, for instance, looks at how close we are to machines making machines — a seeming eventuality, as Johnson tells SYFY WIRE.

“3D printers can now print out fairly customized things. We have automated manufacturing plants. How soon before we can have a 3D printer print out all of the components of a 3D printer and then have machines put that together to create a new 3D printer?” asks Johnson. “I don’t want to be a prognosticator because predicting the future is notoriously hard to do, but we are starting to come up with the components.”

Johnson says he wrote the book to be accessible to anybody, no matter how little one knows about the subject. There will be an occasional equation that Johnson cites, and he encourages people to also try to pick up a physics book to get the most out of his book, but that's supplemental and not necessary.

When it came to choosing what to explore, Johnson tried to stay within Star Wars canon. Sometimes he went into non-movie Star Wars media that was canon, and then he says he rarely makes the leap into Legends material. Out of the whole book and its many topics, there are two areas he enjoyed exploring most. One was Han Solo’s Kessel Run boast, and looking at how it makes sense from a scientific standpoint.

“Let’s say a new neighbor moves next door to you and says, ‘How far away is the store?’ You say, ‘Oh it’s about 10 minutes.’ The neighbor knows exactly what you mean even though they asked; to rephrase the question in a physics way, what is the distance to the store and you answer this is the time it takes to get to the store, because you have a shared understanding of it’s 10 bike minutes or car minutes, depending on which method of transportation you prefer,” he says. “Given hyperspace travel, it could make sense that you talk about these kinds of things in a real space distance.”

Some have suggested that black holes played a role in how Solo’s 12-parsec statement makes sense, and Johnson enjoyed exploring this and the different possibilities that could explain the boast, while also pointing out how in the real world this is done all the time.

His other favorite part of the book was looking at the bongo, a Gungan submarine, traveling through the planet core of Naboo in The Phantom Menace. Johnson says the movie implies that Naboo has water from surface to surface, right through the core, and in principle, it’s possible to have a planet like that, but as he thought more about it, that led to certain implications. For example, how the temperatures for the freezing and boiling points of water change when it's under a lot of pressure. For Naboo, the water at the bottom would be under a lot of pressure, and more likely to freeze.

"If you do that, what is the radius of the planet able to be before the deepest water is under so much pressure it turns to ice? One of the reasons I enjoyed writing this section is I just naively did the calculations and said, 'OK, how deep is the water?' But then I thought: 'Wait a second, as you go closer to the center there's less of a force of gravity because there's less stuff,'" says Johnson. "If you go to the perfect center of a planet there's no force of gravity because on all sides it would be pulling it towards it, so there's no force of gravity. This means that the pressure behaves in a more complicated fashion as compared to my initial approach."

Then he had to redo his calculations.

“It was one of those things where I knew the basic physics, but as I explored it, I realized there was a richer vein of physics in there that I hadn’t even considered the first time around, and made it, in my opinion, more interesting,” he says. "I compared this to the depth of the Mariana Trench for instance."

He also says that no one had ever put water under that much pressure, so they can extrapolate what it would be like at these temperatures, but technically they don't know.

"One of the other interesting things that came out of it was, 'OK, the core of this planet is made up of water not a molten iron core like the Earth," says Johnson. "The molten iron core of the Earth is what generates the magnetic field around the Earth, which protects it from the solar wind and other charged particles, which in principle would do a lot of damage to our DNA and cause it to be very difficult for life to exist on the planet."

According to Johnson, if Naboo truly has water at its core, then it doesn't have that molten iron core or a magnetic field. It's unlikely the planet is in a place where there were no charged particles or cosmic rays coming at it, so that meant there had to be other answers.

"Maybe they set up some kind of magnetic shield defense to protect the planet from this, or maybe the inhabitants are super resilient to radiation and just developed life that way," he says. "Maybe that's why the Gungans live under water, because water is a great protector from radiation. Maybe that's why they developed underwater because there was this problem with charged particles coming and making it difficult for life, so it would make sense for an underwater race to develop on the planet."

So what path led Johnson to writing this book? He's been a Star Wars fan for a long time, having been first introduced to the franchise when he was around five years old. His love of Star Wars continued as he grew up and continued his education, and eventually, that love also found its way into his work. Johnson has been a full-time professor since 2012, and one of his first exam questions in his Intro Physics 101 course was about Yoda using the Force. It asked how much Force it would take to lift that X-wing out of Dagobah’s swamp, a question first prompted by Randall Monroe’s What If? blog on XKCD. Johnson then also incorporated other similar questions throughout his class. Now, he spends a lot of his time trying to make physics relatable with the use of a fictional universe like Star Wars.

"A fictional universe with magic brain powers and laser weapons and stuff like that is not exactly the most realistic all the time, but it is a very relatable thing, especially using other films and other pop culture things in physics," Johnson explains. "The classic example is doing sports problems, but not everybody likes sports, and so incorporating movies and stuff really helps people relate to the content and think to themselves, ‘That’s a thing that I’ve seen,’ or ‘That’s a thing that I know and love and I can appreciate both this thing that I love for what it is and also the physics that is embodied inside of it.'"