The science behind May the Fourth

Today is the day that Star Wars fans around the world wait for — it's the day to celebrate hyperdrives, lightsabers, Wookies and the best/worst pun of all: May the fourth be with you.  

'Star Wars' seems like such fantasy, is there a reality to any of these movies?

Take the foreign world Tatooine, the desert planet where Luke and Anakin Skywalker lived when they were young. This is a world in a binary star system where the planet orbited around two stars that orbit each other (well, technically they orbit a common centre of mass). The idea of a two-star system is very much something we see in our own universe, and a habitable planet in a two-star system is most definitely a reality. 

I spoke with Siegfried Eggl who is a post-doctoral fellow with CalTech working at NASA's Jet Propulsion Laboratory where he studies these binary star systems.

"We already found like thirty planets that are in this configuration. I think what's amazing about that is of those thirty planets that we've uncovered so far, six are already in the habitable zone of the system," he said.

"Everybody would imagine Tatooine to be a very desert planet, but in fact it turns out that if you put the planet there with sufficient water, like the Earth for instance, then it would retain all the water. So it turns out that you have to go a little farther out from the two stars in order to retain Earth-like climate, but you could have them, so there's no need for Tatooine to be desert-y at all, actually."

So the only thing that the movie got wrong wasn't that Tatooine could exist, but it was just less like the Sahara than depicted.

There's no doubt thousands, if not more, habitable planets exist in our universe. Getting there is a bit of an issue right now and studying them is hard, but they are out there, and there's probably a real world that can match any Star Wars fictional worlds depicted in the saga.

How do we get to these far flung locations?

Sorry, going the speed of light is impossible. The hyperdrive in Star Wars is something that, theoretically, contracts space ahead of the ship and expands it behind to propel it through space time. Right now though, it is impossible, even theoretically impossible, for anything with mass to travel close to the speed of light without requiring infinite energy —which is also impossible.

But don't be dismayed, there may be a way to travel to different areas of our universe or galaxy, and that's by taking a short cut through a wormhole. 

I spoke about the feasibility of wormholes with Jeanne Cavelos, an astrophysicist who also wrote a book called The Science of Star Wars, .

"What we need to do is, we need to be able to form one when we want it, then we need to be able to expand it, so they're big enough to get the Millennium Falcon through, and then we need them to stay stable," she said. "Now to do that, we need something with an anti-gravitational force, and that, theoretically exists. It's called exotic matter, and it has negative mass."

At this point in the calculations, you'd need an object of negative mass about the size of Jupiter. I never said it was going to be easy!  It just may take longer than our lifetime to realize it.

What about the lightsaber?

Yes, the lightsaber, the most iconic weapon ever imagined. I spoke with Don Lincoln, a senior scientist at Fermilab, a research centre where science fiction is not fiction at all, it's inspiration to think more about how it can happen

"We saw in The Phantom Menace that Qui-Gon stuck his lightsaber in this heavy blast door and melted it, so, you can see how thick the door is. You assume it's steel, measure how many seconds it takes to melt how big of a swath in it, and you can come up with the energy output of that lightsaber, and it's something like 20 megawatts, which is an awful lot of energy. Now, 20 megawatts of energy stored in the handle, maybe that could be something you could imagine, technology doing, but you have the issue that it's able to generate sufficient heat to melt a blast door, and yet the Jedi's hand is inches away from the blade, and it's hard to imagine you wouldn't burn the person's hand off."

But to make a real non-Jedi Force-requiring lightsaber, the energy is the hardest part — how do you hold that much energy (20 megawatts is enough to power about 15,000 households) in your hand that can do all of those things without being either ridiculously heavy or large, or simply too hot to handle.

Does that mean the take home is that Star Wars is mostly fiction, but has some grounding in reality?

Yes, exactly. I don't think Star Wars would be as famous and as ever-lasting as it is without some element of reality to the fantasy.