It's fun. There are two angles you can come at how lightsabers work from: how they work in the Star Wars fictional universe, and how something like that might work in our universe. The former builds out the fictional universe into something more "reasonable" in the sense that you can reason within the internal rules of the fiction. Reasoning about fictional worlds, especially with other people, is very fun (see D&D, or religion). The latter is a fun scientific diversion that could even lead to real inventions.

People like to talk, and often already debate real life things to a level that borderlines on tedium, but they enjoy it. Anyone who has been in a group of academics in a conversation are familiar with this.

When it comes to fiction, I don't look into it too deeply, but suspension of disbelief only goes so far. The logic of the work must make some kind of sense in the world that it takes place.

• If there is a civilization underwater, did they evolve to have gills or do they stay inside oxygen filled bubbles?
• If you can move objects with your mind, can be strengthen like a muscle and does it get tired out?

And the most important:

• If a character is evil, why are they that way? Lost sight of a lofty goal? Revenge for a past wrong? TBI?

This is why I'm not a big fan of "magic" because it seems like a lazy way to explain a phenomenon in fiction.

Equally pointless as reading fiction in general, playing a video game, or daydreaming.

Because it makes things more interesting. What do you like to talk about? Whatever it is, there's someone who would tell you it's pointless. The point in talking about fiction is the same as the point in consuming fiction in the first place: it's entertaining

Just an insight into someone else's imagination.

Which is exactly why it can be interesting to discuss?

Edit: to add to everyone else saying "it's fun," it's not just about that.

For me, it's important that fictional stories (particularly outlandish subgenres like sci-fi or fantasy) must have internal consistency, unless I lose my ability to suspend disbelief.

Sometimes that means checking that the internal logic the author is using makes sense and stays consistent.

It's an enjoyable way to engage with fiction and think critically. Everyone in the debate knows lightsabers aren't real, but there's established in universe rules and community-agreed principles you typically frame your arguments on. This can keep a piece of media alive for fans, if it was just about watching movies and not really examining them then there wouldn't be much reason to revisit them, which I feel would be a shame after writers put so much work into creating a universe to explore.

It can give you a good reason to continue to engage with the content, or engage with a community of people who also enjoy the content. In my case watching Star Trek is fun and all but not if I'm just mindlessly consuming the show. Looking at a ship's engine, liking engines in real life and saying "I wonder how that thing would work" is a good mental exercise, especially when you've found others who have the same questions.

You're that guy in the comic yelling at everyone to "Stop having fun!".

It's because people can talk about anything they want and don't even know you exist.

I don't think a post has ever felt this alien to me. Lol.

Enjoying fiction at any level is an exercise in tricking yourself that something fake is something real, but the deeper you can take that process, the more fun the experience is.

Those of us who do that type of thing are unsatisfied with "insight into someone else's imagination," which sounds like an extremely shallow appreciation for fiction. We want full immersion in that imagination. With that comes an appreciation for internal consistency, well thought out lore, curiosity in how different universes we care about might interact, disagreements with any of the former, etc. all colored by our real lived experiences.

I'll use your example as my example. I'm a big STEM guy, so naturally, I appreciate thinking that's more in line with those areas. I think George Lucas' idea of lightsabers being lasers frozen in place is dumb. I prefer to think of them as electromagnetically contained plasma, which also explains other sabers and laser/plasma projectiles bouncing off of them. That headcanon allows me to appreciate lightsabers (and thus the stories around them) more. That headcanon is also fun to express to others (like here).

Fun thought experiments. Like, for example, The Flash has been portrayed as so inconceivably fast that why couldn’t he instantly transport anyone, anywhere and entirely replace all of the world’s manufacturing plants?. It’s absurd and amusing to think about.

As others said, it’s fun.

Also, it engages critical thinking. One has to examine, make a claim, and defend with evidence. It may be silly, but it’s fundamentally helping you to think better.

I used to say that about people who discuss movies and football, but then I realized I'm just like them when it comes to music. I don't see any reason to mock people's trivial interests or claim that our triviality is somehow better than theirs. Life is harsh, and people just want to be happy.

Discussing how light sabers work is relevant to technological progress, many real life inventions were inspired by sci-fi (some even out pace sci-fi like with the Star Trek communicator vs the real life smart phone). Super hero fights are relevant so when avengers civil war or Batman vs Superman is announced you can make your bets on kalshi

It’s a further exploration of the concepts. Thinking about how light sabers work gives you new ideas on hot the world has evolved over time. Why do they exist s but are so restricted? Then you can use your imagination to fill the gaps of the narrative. It’s a way to make the story interactive and make it yours.

Maybe they discuss it to get an insight into someone else's imagination.

As it was already said, it's fun. Because it's almost like trying to solve a puzzle. A well thought out world has incredible internal cohesion and mulling on it reveals angles that aren't necessarily even explicitly pointed out. Realizing that interconnectedness is immensely satisfying (even if you only have it pointed out to you) and makes you appreciate the work even more. Let's say a fantasy world where there's a well thought out magic system, and a well thought out financial system - and thinking on it reveals that the two are very interconnected, even if it's never highlighted in any way. It's a meta-story within the story. Popular fiction tends to have a lot of this, which makes it a popular topic for discussion, which makes it more popular. Brandon Sanderson's works are a great example of this. One Piece is a great example of this. I'd say the satisfaction of interconnectedness is also why multiverse stuff is so hot these days, though most of it is executed in a fairly lazy way (just piling things on top of each other and handwaving anything that doesn't gel as "well, it was another timeline", looking at you Marvel).

Of course sometimes there are some works that ride on such nice vibes that you don't really care that it doesn't really make much sense. Harry Potter being a good example (or at least was before Rowling went off the deep end). HP world building is actually so flimsy it's embarrassing, but it still managed to tap in to such a good idea of a fantasy that people were largely willing to overlook it.

Insert the stop having fun meme.

the pointless things are the most fun. also, there are things like consistency, you can have magic with boundaries for example, the rules dont have to be real to be discussed. but if its not your cup of tea who cares :D

To develop a deeper understanding of and apprectikn for a universe.

A lot of science fiction has to put some emphasis into world building because it is how they create the settings in which their stories work. The setting is narratively important in a way that it isn't for a medical drama since the audience can't backfill seeing information from their personal knowledge base. The Tommy Westphall Universe was presented as a critique of this requirement as, if you followed crossovers, most of American television occurs in the head of Tommy Westphall.

So why is it important how pretend worlds work? Well, it creates a place for stories and plot to exist without the baggage of reality. It also creates interesting implications for how we view our own world. For instance, the transporter issues in Star Trek have spawned a lot of conversations on personhood in the wake of copying things. It also becomes a way to talk about ethical issues before technology catches up to create an ethical issue.

Some of it is fluff, but there are interesting ideas being discussed within the worlds we make.

It is fun to talk about things you enjoy, regardless of how pointless it is.

Ask my kid anything about Minecraft and you will see the light of joy it sparks in her eye. She knows it is pointless; she could make up half the words and it wouldn't matter, but she still gets joy about talking about it and that's the point i guess.

I did a similar question once and got my answer delivered through a book I was reading then: fantasy knows no bounds.

Many technological breakthroughs and discoveries were made because someone decided they wanted to test if some weird or outlandish concept a writer put in a novel or a television series actually holds up to the real world.

And regarding discussing super heroes fighting each other, it is a good way to plot ideas and concepts. It's a mental exercise. In similar way to philosophy or religion.

Its just the modern version of mythology. Its the same as arguing Zues can piledrive Ra.

The same reason people discuss religion logic.

its fun, if it sometimes is relative to "physics" concepts, like FTL tech, or how someones powers work, reality warping, teleportation, or raw strength.

lik Evangelion, how the the angels work, thier reason for thier current form,,,etc, like thier core houses thier "soul" and S2 engine the power source of angels, which gives them significantly more control in producing unlimited power to give them the ability to put up a energy shield, and power thier energy weapons, or defy physics. while "humans" only have the same energy field to maintain thier form thats about it.

Its fun :)

An example could be Star Wars, where they discuss how a light saber works.

It's worth noting that fiction can and has led to new inventions before. So, discussing how something could work in real life, could lead to people trying out new things because they were inspired by a book.

https://www.youtube.com/watch?v=bWb9cxTYcD4

It's nice to have hope for something, even if it's a fictional universe.