Besides the obvious reason of a power source, maybe they built around a star because it led to a way to shed the flesh. Or perhaps it was only a summer home?
As per upthread, they would't even need to hide. How could our heroes hope to detect them? It takes them dozens of seconds to scan a planet for lifeforms. Even after centuries of scanning, they simply might not have hit the right spots on a Dyson sphere that is 95% inhabited. Add to this that their ship was broken and they were in a hurry (for whatever reason - we never learn of one). All we know in the end is that the Spherites weren't hailing them, or sending spacecraft. That would allow for a hundred thousand separate industrial civilizations, or for mildly private advanced ones. Timo Saloniemi
And why would Scotty do that when he's an accomplished engineer and the ship is actively flying... Scotty is arguably being used as a punching bag by the writers solely to score a cheap and ageist narrative at the expense of known character traits. And Scotty wasn't anywhere near Admiral McCoy's age...
Well, aging is all about losing your character traits (among other things) and either coping with it or not. We saw a process that might be considered the former. What narrative isn't "cheap"? These characters live, die, suffer or triumph purely for the story. Any illusion of them being real folks comes from reading between the lines, that is, seeing patterns in flat white. Scotty was born to be a punching bag, a phaser target, a butt of jokes. And then got Chekov on his side, and almost lost his justification for existing. So some all-new jokes and torments were invented... Timo Saloniemi
By that point in TNG's run, its storytelling was lagging compared to other television. Something like the Dyson Sphere could have supported a multi-episode arc, like other dramas at the time were doing. There are a lot of things to criticize "Relics" for, like the way it handles Scotty, but using a Dyson Sphere as a throwaway MacGuffin is its most unpardonable sin. I sometimes think about TNG occasionally adopting the narrative, arc style of Wiseguy, and I get kinda sad that it didn't.
May I kindly request that Maurice practice his Google-fu in the future when seeking information than can be obtained in a fraction of a minute with practically no effort XCV330, In case you didn't see my post right above yours (we all comment without reading the whole thread sometimes), you might want to go take a gander and see that idea fleshed out in fiction. Thanks for the info about that being an accepted hypothesis!
Praise the Lord that they didn't do weekly television shows like that. TV shows like that wouldn't have worked as well back then when there was One night a week and One time to watch Your show. No , Netflix, no Hulu, YouTube, etc. if you missed your show that week possibly you could catch it the One time they Might re-run it during the summer.
One shouldn't have to employ Google to follow a conversation. I wouldn't wander in here and start talking about the crew compliment and maximum speed of Federation Pursuit Ships without adding the qualifier that I'm referring to the Terran Federation of Blake's 7. But maybe that's just me.
Another non-canon explanation for the Dyson Sphere crops up in the MMORPG video game Star Trek: Online, where it is discovered that: Spoiler The Sphere is just one of many created by the Iconians (oh yeah, they're back) or one of their proxy races - the Solanogen-based lifeforms from TNG's Schisms are heavily implicated - for the purposes of creating Omega particles. Since the Iconians travel via Gateways, the ability of Omega particles to destroy subspace and thus prevent warp drive are a useful weapon for them to strike at the "lesser" spacefaring races. The Jenolen Sphere (called this to distinguish it from others) is discovered to have "jumped" from it's original location (with the survey ship USS Gold inside!) during one mission. There's also another Sphere located in the Delta Quadrant, which becomes a contested battleground with the Voth (who are out to steal the Omega particles for themselves).
Always bothered me a bit that a race so advanced they could build such a humunguous Dyson sphere couldn't detect/predict the star's instability before building it. Then again of course, the sphere could be old. Perhaps they were perfectly capable of predicting it but decided that the billion-year use they could get out of it before the star would become unstable would be worth the investment ....
Or then they first built the sphere and then wrecked the star. If they can do Dyson spheres, then manipulating stars ought to be a breeze, and a likely means of warfare or vandalism or whatever. Or then the star is fine, and our heroes just don't realize how it's perfect for the needs of the inhabitants... I wonder why they are keeping Harry Mudd's role secret. And the whole Metron/Q/Quinn/Trelane connection. Timo Saloniemi
Even our star, stable.. ish as it is, in a billion years, will be 10 percent brighter.. so if we put a shell around it, the star will change given time, so the shell may be millions of years old, and the people either moved, or accended and left it be..