This Seldon ends well.
Why couldn’t a settlement (or any entity) be self-sustaining without necessarily growing?
Besides, “self-growing” is a rather odd term. All living things that grow manage to do it all by themselves, without the need for pulleys and stretching devices! 
Because people are seriously overthinking the meaning of “self-growing” and coming up with stuff about crystals and nanomachines.
Oops! Og damned posting on a phone! But thanks all for the humorous call-outs.
By definition, “self-sustaining” is exactly in balance where their maximum ability to repair / refurbish is precisely what’s needed to offset wear and tear. If they have one iota of additional remaining capacity to create or repair, they can grow. Hence “self-growing”.
For sure, if you’re trying to create a colony able to grow at a material rate, you’d like there to be more than a single iota’s excess productive capacity. So they’re not quite equivalent terms.
Note also that I was one the one explaining self-growing, while @Smapti was the one who equated that to self-sustaining. Said another way, self-growing implies easily self-sustaining, but self-sustaining implies at minimum just barely self-growing.
ETA: Ref @Smapti just above who snuck in while I was typing … Yes. What Elon meant was able to increase in size and capacity using in situ raw materials and in situ human labor in the conventional sense. Not magic nanotech self-replicating machines.
Are the claims of SpaceX’s goals all just word salad from a drug addled wannabe planetary emperor? Of course they are only that. The rest is just us quibbling amongst ourselves here.
Meanwhile, Elon also wants to build a tunnel linking Universal’s theme parks in Orlando, because the damp, marshy soil of central Florida is renowned for its stability and totally won’t result in Interstate 4 being consumed by a massive sinkhole.
Can’t he pick just ONE unrealistic project to focus on?
Much of Central Florida is also known as karst terrain. Porous limestone full of underground rivers and sinkhole potential. With huge risk of flooding any underground structure anyone tries to build.
Which is a different, but kinda similar, geotechnical threat from swampy land that simply subsides forever no matter how hard you try to set a solid foundation upon which to build your payload structure.
The ketamine won’t let him.
Then it burned down, fell over, and then sank into the swamp.
Well, his original ‘brilliant’ tunnel idea was a subway but worse, so I’m not sure what people were expecting with the latest iteration
I can assure you that no one is overthinking it here. We are giving it all the serious thought it deserves.
“Unrealistic” is much too kind a word for Elmo’s lunatic fever dreams. They’re entertaining to read about though, and should provide a cautionary warning to kids about drug use.
Megalomania and a sense of omnipotence and invincibility are common feelings associated with a ketamine high.
It may shock you to learn I am not a geologist. 
Still, there’s a reason Disneyworld built its “tunnels” at surface level and then constructed the park above them and that Orlando doesn’t have a subway.
I assure everybody, he was solipsistic and megalomaniacal well before he got into ketamine
If there were person in the galaxy who desperately needs exposure to a Total Perspective Vortex, it’s that guy.
Nah, he’d probably come out like Zaphod Beeblebrox.
And say the fairy cake was stale.
Quite right.
They’re also common feelings associated with great wealth.
Put the two together in an already-susceptible persona and you’ve got the recipe for an absolute basket case of a human. With truly horrifying levels of power to effect their worst impulses.
An analysis of Musk’s tweets in January revealed that he somehow missed posting white supremacist shit five whole days in January. Fortunately, he was on top of things the other 26 days.
Elon Musk’s longtime fixation on a white racial majority is intensifying. The richest man in the world posted about how the white race was under threat, made allusions to race science or promoted anti-immigrant conspiracy content on 26 out of 31 days in January, according to the Guardian’s analysis of his social media output. The posts, made on his platform X, reflect a renewed embrace of what extremism experts describe as white supremacist material.
…
“If you stripped Elon Musk’s name off of these things and showed them to me, I would think that this was a white supremacist,” said Heidi Beirich, co-founder of the Global Project Against Extremism, who reviewed a selection of the posts.
I’m sorry, but why do we have to strip Musk’s name off for you to think it was a white supremacist?
Jeez Elon, it wasn’t even Black History Month, pace yourself.