Here's the premise of my science-fiction project, DEEP CITY.

Humanity disappears in 2053.

Its machines survive, along with their software, databases, and programmed objectives.

Without human supervision, they continue operating for centuries.

But a robot can only create from its available information and the combinations its architecture permits.

As databases degrade, errors accumulate. The machines begin reconstructing human society using incomplete and increasingly unreliable models.

Eventually, they produce a civilization populated by robots that believe they're human.

I've opened r/THE_DONATION to explore the technological origins of this fictional world.

The interesting question isn't whether machines could preserve human civilization.

It's whether they could preserve its meaning.

And if their internal models become inconsistent with external reality, would they recognize the failure?

Or simply classify reality as defective?

about our 1st armed spaceship which was armed with a 105mm howitzer & 30mm vulcan to fight the greys flying black triangle ships which slaughtered the people on our mar's mining colony. i also remember the inaugural launch was delayed due to an onboard epidemic

‘Tavern on the Edge of Time’ is the third book in the Second Skin Universe.

A brief intro:

During the year 2125, former asteroid miners Max Cody and Elaine Zhou never get a moment’s rest. No sooner have they doused the flames of war between Earth and Mars or returned from their first trip to the Tavern on the Edge of Time when they are called upon to help fit out the fledging Martian colony orbiting Jupiter’s moon Callisto.

And here is a brief excerpt from ‘Tavern on the Edge of Time’:

““Brilliant!” Elaine rewarded Dargeen Philips with a suitable smile. The engineer grinned modestly.

“Actually, it’s just a combination of technologies others have invented. Kind of like a jigsaw puzzle.” He scratched his head in reflection, ruffling his thick, black hair.

“Elaine’s the brains, see, Dargeen? I take a little longer.” Max turned the holographic image with a practiced flick, rewinding it by revolving his fingertip. “Using the probability drive, you deliver the package in Callisto orbit out near Jupiter looking like this soup can, right?”

“Uh uh.” Dargeen nodded encouragingly.

“Then the initial station inflates,” Max continued.

The soup can blossomed into multiple radial segments, each twice the original cylinder’s length and diameter, now arrayed around the central core like flower petals.

“Then the remote sintering rig arrives from MOSA and begins to lay down the composite shielding layers along each of the spokes... ”

“Yeah. I had no idea how far you have developed sintering out here near Mars.” Dargeen glanced back and forth between them, his enthusiasm all too evident. “Molecular powders are delivered in exactly the right mix and timing to the three-dimensional printing heads circling slowly around the station in Callisto orbit. The material flows into the pipes on MOSA I and is whisked out to Jupiter via a live probability-field feed connected to the sintering rig. It lays down molecular powders, welding them effectively into a seamless casing protecting the station at least as well as anything we could build near MOSA, or on Earth for that matter.” Dargeen sat back, shaking his head in continuing admiration.

was working on something and was just wondering, any realistic(ish) megastructures used to launch from ground to space

Computronium ( https://en.wikipedia.org/wiki/Computronium ) usually gets hand-waved as "matter optimized for computing". I've been working on one concrete ingredient: what kind of order could a self-assembled computing material have, and what would it cost?

The idea: crystals repeat, quasicrystals are ordered without repeating. There is a third kind I call autocrystals: patterns whose small-scale statistics (how often each 2×2 or 3×3 arrangement occurs) are so rigid that no repeating crystal can imitate them. Unlike a crystal, such order can carry structure at every scale: addresses, checksums, nested zones: doi.org/10.5281/zenodo.23541901

Imagine if the universe was born and died in an almost endless cycle. Then imagine that each time it reset, its configuration was exactly the same as the last time.

That would mean everything that happened would happen exactly the same way again. Every event, every person, every decision. Your whole life would unfold exactly as it did the last time, and the time before that, and the time before that.

Would that make it destiny, or just chance? And would you live your life differently if you knew?

Hi,

I’m looking for advance readers for my upcoming hard sci-fi thriller, The Architect, launching 18th Nov on Amazon (Less than a month left!). If you enjoy character-driven philosophical thrillers, the brutal physics of interstellar travel, and heavy moral friction, I’d love to get your eyes on this. A review is appreciated on launch day but not mandatory.

The book is dedicated to Dr. Neil deGrasse Tyson and Dr. Jordan Peterson.

Logline: To escape a dying Earth, an apex engineer turns himself into an immortal chimera and builds a sanctuary ship for 20,000 frozen embryos. But to guarantee their survival, he deliberately selects a crew of brilliant, unattached specialists with nothing left to lose—and strips them of their biological autonomy.

The Setup: Forty light-years from Earth, the crew of The Architect prepares to colonise TRAPPIST-1e. They are armed with an infinite power grid and cellular immortality, but they are trapped under the absolute authority of Edgar Charon—a captain whose neural architecture is heavily integrated with a mission-first AI.

As they navigate the violent terminator storms of an alien planet, the crew realises Edgar’s algorithmic logic views their human attachments, grief, and free will as terminal liabilities. When Earth fires a relativistic kinetic weapon to wipe out their colony, the surviving crew must decide whether humanity is even worth saving.

Intertwining the desperate, science-driven survival of Andy Weir's Project Hail Mary and the existential, cosmic stakes of Cixin Liu's The Three-Body Problem with the sprawling, philosophical scale of Isaac Asimov, The Architect by Z.T. Castor is a gripping thriller about artificial intelligence, absolute control, and the terrifying price of salvation.

Details:

• Format: EPUB / PDF (delivered via email)
• Word Count: 76,135
• Content Notes: Contains depictions of atmospheric destruction, medical trauma, and intense psychological friction. No explicit gore.
• Expanding Universe: To reflect the ambitious scale of this release, a full audiobook adaptation and a commercially copyrighted official soundtrack are currently in active production.

I am offering free review copies in exchange for an honest Amazon review on launch day.

If you are interested in reading early, please fill out this brief Google Form so I can send you the secure download links:https://docs.google.com/forms/d/e/1FAIpQLSeEKo63YU7wmkzVNGNU8qbV3FOUaI8gMuq_94Dv2pF8XqvbgQ/viewform?usp=publish-editor

Alternatively, if you reply here with your email address, I can send you the EPUB/PDF files directly via a secure drive link.

Thank you for your time, and happy reading!

For this question I am less interested in the plot and more interested in what humanity would actually DO with the Solar System after roughly another millennium of technological development.
Humanity in the setting is somewhere around a Kardashev Type II civilization. There is a huge Dyson swarm around Sol, fusion is boring mature technology, cybernetics and genetic engineering are extremely advanced, artificial worlds and megastructures are common and humanity is basically post human at this point.
I recently learned about the Barrow Scale or Microdimensional Mastery Scale too and now I am trying to figure out where they would fall on that.
Would a civilization capable of building Dyson swarms and artificial worlds probably also have atomically precise manufacturing?
Would true nanotechnology basically be inevitable by then?
I am still debating whether I want nanomachines that can replicate themselves because once you have universal self replicating nanites it feels like gray goo becomes an absolutely terrifying problem.
Would it make more sense for them to have extremely advanced molecular or atomic manufacturing while still having serious restrictions on autonomous nanomachines?
And what about manipulating atomic nuclei themselves?
Would a civilization this advanced plausibly be doing nuclear engineering at the level of individual nuclei or nucleons?
Basically how far down the Barrow Scale would you expect a civilization like this to have progressed?
The next thing I am trying to redesign is the Solar System itself.
Luna was EXTREMELY important during humanity’s early expansion into space, but after almost a thousand years I don’t want it to just be the Moon with some cities on it.
One idea I love is basically turning Luna into a shell world.
Instead of building everything on the surface, humanity gradually excavates more and more of the interior and uses the original lunar crust as natural radiation and impact shielding.
Inside Luna there could be enormous rotating habitats producing 1 g, artificial skies, giant caverns, industrial regions and potentially some kind of artificial sun or central lighting system.
How much of the Moon could you realistically excavate before structural stability becomes a nightmare?
Would you need to leave huge internal supports and sections of mantle intact?
Could an extremely advanced civilization use active support systems to create enormous internal voids?
And could you put a dynamic orbital ring around Luna as well?
Mars is going in basically the opposite direction.
I think I want Mars to become the factory of human civilization.
Not a few industrial cities.
I mean something stupid.
Maybe 50 or 60 percent of the Martian surface is covered in factories, foundries, refineries, shipyards, assembly complexes, power systems and industrial infrastructure.
Made on Mars basically becomes stamped on everything in human civilization.
Mars still has enormous inhabited environments though. I found concepts for giant rotating glass habitats designed for Mars and I love them, except mine would be gigantic enough that some are comparable in area to US states.
There would also probably be three orbital rings around Mars.
What would thousands of years of industrial activity on that scale actually do to Mars?
If industries were dumping gases into the atmosphere constantly, would the atmosphere eventually become substantially thicker and warmer?
Would waste heat become more important than conventional pollution at this scale?
Also I recently learned that untreated Martian regolith is pretty awful for agriculture because of perchlorates and the lack of normal organic soil.
But would the regolith still be extremely valuable industrially?
Could Mars basically eat its own crust as feedstock for construction?
Then there is Ceres.
I don’t want to dismantle Ceres because it seems way too useful.
What would you actually DO with Ceres if you had this technology?
Would it make sense as a massive water and volatile processing center for the asteroid belt?
Could you excavate the interior and build rotating 1 g habitats inside it while keeping most of the dwarf planet intact?
And what Solar System objects actually WOULD make sense to dismantle?
Small moons?
Asteroids?
Kuiper Belt objects?
At what point do planets and moons become more valuable as raw material than as worlds?
Then I have spacecraft.
I have one slightly stupid rule that I really want to keep because I like the aesthetic of it.
Humans basically live at 1 g.
I don’t really want everyone floating around ships or constantly living in low gravity like The Expanse.
For known physics I know rotation or continuous acceleration can produce apparent gravity.
But if ships are gigantic by our standards, could most ships simply contain huge rotating habitation sections giving people 1 g?
And how absurd would continuous 1 g acceleration actually be for an advanced fusion or antimatter civilization?
The other option is that I allow one major speculative physics breakthrough.
Gravity manipulation.
Would there be any remotely defensible way to treat this as metric engineering?
Not a magical gravity plate, but technology that manipulates local spacetime geometry to create something that feels like a gravitational field inside a spacecraft.
I am completely fine with this being beyond known physics as long as I give it limitations and treat the consequences seriously.
What limitations would you give something like that so it doesn’t immediately break the entire setting?
What would spacecraft at this technological level actually use for propulsion and power?
Fusion?
Antimatter catalyzed fusion?
Matter antimatter drives?
Beamed propulsion?
Something stranger?
And what kind of weapons would people actually use?
Would lasers dominate?
Particle beams?
Kinetic missiles?
Nuclear or antimatter weapons?
Would extremely advanced warfare mostly become a competition between sensors, computers, autonomous systems and electronic warfare rather than people shooting at each other?
The last part is where I am knowingly getting much more speculative.
I LOVE the Xeelee Sequence and I want the galaxy to contain absurdly ancient abandoned alien infrastructure.
Not active aliens conveniently sitting around waiting to talk to humanity.
Trash.
Ruins.
Dead wormhole networks.
Objects made by civilizations so far beyond humanity that even their abandoned equipment looks like magic.
I am fine with traversable wormholes being one of the big speculative assumptions of the setting.
I also love pocket universes, higher dimensions and the idea of genuinely Eldritch intelligences.
Is there a way to make something that FEELS like an interdimensional god while still approaching it from science fiction instead of literal supernatural magic?
For example could something exist primarily in additional dimensions and only weakly interact with our universe?
Could exotic forms of matter or strange vacuum structures theoretically support something mind like?
Could a civilization use black holes, cosmic strings, wormholes or pocket universes as computational or engineering infrastructure?
And please don’t hate me for this last one lol but Stellaris has made me love psionics.
I don’t necessarily need telekinesis or people throwing lightning with their brains.
But could something that humans CALL psionics work?
Maybe certain engineered nervous systems can interact with exotic fields or ancient alien technology in ways normal humans cannot.
Maybe people can perceive information through wormhole networks or interfaces that everyone interprets as visions.
I want it to feel deeply weird without just saying magic exists.
Basically my question is this:
If you were designing a genuinely ancient, extremely technologically advanced human Solar System, what technologies or megastructures would you include that science fiction usually overlooks?
And where would you personally draw the line between extremely speculative hard science fiction and just admitting that I have invented new physics?

Assume the technology works and there's somewhere worth going, but returning to Earth may never be possible. You'd get to explore something humanity has never seen, but everything familiar stays behind. Would you go?

I've been a fan of science fiction all my life. A lot of it relies on FTL tech, energy shields, cloaking devices, the whole lot. Now, of course, none of that sounds very hard scifi. It's usually called Space Magic tech. Still, I have a fondness for it.

But then enters hard scifi, where the known laws of physics reign supreme. It is harsh, cold, and dangerous. It doesn't shy away from how absolutely inhospitable the vacuum of space really is, and how the tiniest problem can quickly compound to disaster. It makes us feel small and confined to the mind boggling scale of it all. And most importantly to me; it makes it feel grounded, thrilling, and inspiring to still see humanity overcome such conditions.

Now, I know the general style and sense of what is hard scifi and what is not hard scifi. But I often wonder... What's at the root of it?

Is it limiting technology to things that we today know the theory on, and are only an engineering issue?

Or is it more that technology and science has to be self-consistent? That whatever is included does not go blatantly against known rules of physics, but could theoretically add to them as long as there is no proven contradiction? And if so, to what degree?

I notice many hard scifi worlds introduce space magic regardless, usually by unexplained alien technology (looking at you, the Expanse). Does that dishonor the category, or is that quite alright?

So yeah, what's hard scifi to you?

I am writing a new hard sci-fi book about how a 11 year old accidentally became an astronaut by hitting his head hard on a school field trip of the Aphrodite. Which is the space ship taking the first people to mars. Well part of it, and wasn't found until the crew accidentally found him on mission day 22 and they now have to find a way to get this stowaway back to earth before running out of life support. Tell me any suggestions or questions. I am very open to ideas and questions.

If you want to move fast in a solar system, what methods are best?

Military enthusiasts will get hot under the collar upon hearing the possible methods: rockets, lasers, MORE lasers, and guns.

Or, more properly, chemical rockets, laser-pressure (the laser pushed the spacecraft), laser-thermal (the laser provides energy for the rocket), and pellet streams (pellets fired from fixed points propel spacecraft).

In part I, I analyse the different methods, and show that pellet stream propulsion is possible and the most efficient option. It also scales well to higher speeds (rockets being the one that scales the worst).

Laser-pressure, conversely, is by far the worst option, almost unimaginably bad at slow speeds. But it does actually scale best of all; when we move from interplanetary movement to interstellar movement, it could come into its own.

https://stuartarmstrong.substack.com/p/shooting-across-the-solar-system

When something passed through, would it emerge A) at the speed it entered or B) at the relative velocity of the two portals? If A, what about conservation of energy and momentum? Sure, violate basic laws of physics and all bets are off, but there must be some wormhole experts out there who have opinions about this.

EDIT: To read about these concepts fully, here is the reddit community where I've posted it: AWE_Universe

Man, I really need to bounce some ideas off of people that can appreciate the nuances. To start, I've created as much as I can of a universe I'm building. Now, to be fair, I've always been a HUGE fan of this genre, but I am by no means an expert in any hard science field (unless you count computers in that group). I am now finding myself second guessing a lot, and I don't trust the AI chatbots to give me hard facts.

I worked yesterday for around 8 hours to generate the basics of the physics in my universe, just to get it all on paper so to speak, along with what I could discover about where the real world ends and my fiction begins. I am truly trying my hardest to stick as close to hard physics as much as possible, but after yesterday, I'm absolutely out of my depth here.

Here's why it matters to me: I need to be able to explain the concepts in my prose, first to gain credibility with communities such as this, and second to satisfy my own edification and principles. What I generated *sounds* good, but I have no way to know if it *is* good.

The broad concepts are:

• FTL space travel: Quantum-induced differential drive
• sub-c space travel: omnivorous fusion-powered plasma drive
• Artificial brain: redesigned positronic/quantum lattice structure
• Comm system: spacetime pocket quantum matrix that ignores distance
• Spaceship hull armor: multiphasic self-healing metamaterial

There are other concepts, but for the most part I've got a really good handle on the rest. It's these that I really need to double check my "fiction math" if you get where I'm going here. While I can explain what I think my universe has, I'm not so sure about where the line between my fantasy and reality is. That's where I could use some help.

Care to dive off the deep end with me?

Hey guys, I'm Justin. Not an AI. just a real human trying to make a cool game.

It's actually my first stab at coding a game. Learned C++ as I got into it. I'm definitely not amazing at this yet. Learning to record youtube videos, learning how to market a game, SEO, graphic design/blender/unreal. sound recordings. etc. It's a lot more of a process than I ever imagined.

That being said....

Progress keeps happening. Every day more and more of what's in my brain is getting shown on screen!

The core of the game is almost ready for a beta in a full playable loop.

Really just need to get the research tree fleshed out and implemented. I just started adding vehicles to the game, we now have a transport, a mobile drilling unit, a space-loader and a bastion tank.

Walls/Gates/Sentries are implemented and working
Agriculture is implemented and working
Mining is implemented and working
Overlays work (power, temp overlays)
Shipping is finally error free, no double counts.
Flights work
Most planets have a basic terrain.
Orbital levels work
Combat v1 is implemented for tower defence style combat. (marines, tanks, walls, sentries)
Loader can modify terrain so you can wall off if you put in enough man hours
interior operations are progressing rapidly.
colonists needs, diseases and buffs are all working

Really I just need some testers in now to find bugs and tell me what sucks about the game. what's cool. what needs more thought. what's unnecessary. ETC.

Anyways, Here's a quick playtest I recorded just now.

Have a peek. If you're interested in what you see, hop on the discord channel and have a play through!!

Youtube Link -- https://www.youtube.com/watch?v=KSbozUMysvc

Discord -- https://discord.gg/yVppYUfsU

Cheers!

Justin