Yes, it’s Star Wars Day again! The Star Wars films base their wow-factor on their adoption of science and technology in their settings and storylines. But do the movies actually involve any science or is it even bad science? They have certainly showcased many fantastical technological concepts.

Some people say that the point of science is to help us understand and give our lives value. But does it make us less amazed and amazed by the world around us like we were kids? We feel awe when we see or experience something huge and strange. As adults, we tend to think of awe in terms of big events, and we lose the ability to feel awe in small, everyday things. I would say that knowing about science doesn't have to stop you from being amazed, but it can make you wonder a little more. Yes, of course. While some newer science fiction films try to show how scientifically sound they are, Star Wars doesn't care about the rules of nature.

Things like R2D2 and C3PO, the self-driving robots that amazed us in the original 1977 movie, seem pretty ordinary now that artificial intelligence is getting better all the time. However, two of the movies' most famous ideas—lightsabres and travel faster than light—still excite both kids and adults.

Lightsabres

The lightsabre is without a question the most famous piece of technology in Star Wars. Those strong beams of light can cut through metal like a hot knife through butter. With what we know about science, we wonder if they are actually possible. It's likely that the idea of lightsabres having power has been the subject of many a talk. In movies, the blade comes out of a handle that looks like a medium-sized torch. It's a set length and can cut through anything except other lightsabres. Plasma is the only thing we have right now that can cut (almost) as well as a lightsabre. The fourth state of matter is plasma, which is ionised gas. Plasma tools cut metal into thin slices. This is a problem: metal needs to be hot in order to be cut. Very warm. Heat that is at least 40,000 degrees Fahrenheit high. The person still needs to wear safety glasses and gloves. As soon as someone touched the handle of a lightsabre, a beam of plasma the size of the blade would fry their hands. Your triple-A batteries aren't going to give you enough power. To get the power needed to make a lightsabre out of plasma, you would need a much bigger power source.

The plasma that comes out of the cuts used for welding is also very small. It's only a few millimetres wide. Most plasma cutters are hooked up to something about the size of a car battery that changes the energy that comes from the wall into a different form. Think about what it would take to make a 3 foot blade. Since you have to plug it into the wall, it makes it harder for people to fight with their lightsabres while roaming around and jumping and running. You'd get caught in the cord, just like when you dust. Two plasma blasts would pass right through each other, which means you won't be able to fight like the Jedi. There you have it. You can have a lightsabre fight if you don't mind using a plasma that's millimetre-sized, wearing a suit that won't catch fire, and plugging into a converter the size of a car battery. You could say that "knowing" ruins the dream, but that didn't stop Russian Alex Burkan from making his own lightsabre that retracts. Burkan applied what he knew about science to make a machine that makes a plasma blade more than 1 m (3.28 ft) long and hotter than 2,800°C (5,072°F). Also, the blade is strong enough to cut through steel. Get smart!

Light speed

Han Solo is happy to say that the Millennium Falcon will "make point five past lightspeed" in the original Star Wars movie. Let's take a better look at what that means. Let's not worry about the fact that we know of no vehicle that can move faster than light. The famous equation E=MC2 says that as an object gets closer to the speed of light, its mass increases at a very fast rate. To keep going faster, you would need more fuel. 470 tonnes of Nb–Ti superconductor are used by the Large Hadron Collider (LHC), which is the world's most powerful collider and speeds up atomic particles almost to the speed of light. During LHC operations, the CERN site uses about 200 MW of power from the French grid. This is about a third of the energy that the city of Geneva uses, and about 120 MW of that is used by the LHC collider and detectors.

186,000 miles per second is how fast light moves. The Falcon can move at about 279,000 miles per second, which is what Han Solo meant when he said that it could move at 1.5 times the speed of light. That would go by quickly. "Space is big," though, as they say in "The Hitchhiker's Guide to the Galaxy." It's so incredibly, incredibly, mind-bogglingly big that you won't believe it. You might think the chemist's is far away, but space is way farther away.

Star Wars takes place in a galaxy that is about the same size as ours. It would be about 100,000 light-years across, since light travels about 6 trillion miles per year. At the speed of light, it would take 100,000 years to get from one side to the other. If you go 1.5 times the speed of light, that's about 75,000 years. Still, Han brags that he has been to every planet in the galaxy! It's true that Harrison Ford is getting old, but how old is he really? To give you an idea of how far away it is, Proxima Centauri is only 4.2 light-years away. The Millennium Falcon would still need a little more than 3 years to get there.

Last but not least, we need to talk about time dilation. When comparing speeds, the faster one is, the longer the time difference between them. Time stops moving as one gets closer to the speed of light. In the world of Star Wars, old friends and enemies fly around the galaxy and sometimes meet up for fights or other events. But how can everyone stay in the same time frame? It's well talked about in a science fiction book from around the time that George Lucas was planning his world. The American author Joe Haldeman wrote the military science fiction book The Forever War in 1974. It's a thoughtful story about soldiers from Earth fighting an interstellar war against an alien society. Soldiers move through "collapsars" that connect to each other and let ships fly over thousands of lightyears in an instant. But, and this is very important, travelling to and from the collapsars at almost lightspeed has huge effects on relativistic time. In one timeline, the main characters make it through four years of military service, while many ages pass for people in general.

What fan didn't enjoy seeing the Millennium Falcon jump into hyperspace, the epic fights with lightsabres, or the Death Star finally being destroyed (twice!). Science fiction has almost turned into a modern mythology, and it's a genre that speaks to a wide audience in films in a way that writing can't even begin to. People find the "sublime" to be one of the most appealing things about science fiction, like in Haldeman's work. The "sublime" is a psychological and aesthetic idea that can mean greatness, power, and limitlessness. The expression of the sublime in films makes people feel "awe." In the past few years, more and more theoretical and empirical works have investigated awe as a complicated emotion. Even though the Star Wars movies are great, a lot of what we saw isn't possible in real life. That's why it's called science fiction.