What the evidence is for
What is being built
The aim is one build that answers the whole threat list at once. Sorting by response rather than by cause turns eighteen arguments into six things worth having. Nobody has to be convinced about the micronova to have a use for it.
One
Sorted by response, not by cause.
Eighteen threats are set out at Grain by Grain, with the six preparations that serve every one. The threats have almost nothing in common. The preparations are the same six.
Volcanic winter, a pandemic, an undersea cable cut, a transformer bank lost to a geomagnetic storm. What the household in the middle of one experiences is close to identical. Power gone. Water not arriving. Food thinner than the shelf suggests. The person who knew how to fix it unreachable.
| The preparation | What it answers, regardless of cause |
|---|---|
| Energy that islands | Generation and storage that can cut off the grid and keep running. Covers storm damage, sabotage, fuel supply, price shock and a grid that gets old. |
| Water that is yours | Held, cleaned and cycled on site. Covers drought, contamination, pump failure and a treatment plant with no power. |
| Food and fixing | Growing close to where the eating happens, and the parts to repair what breaks. Covers crop failure, freight interruption and a spare part three weeks away. |
| Knowledge that stays | Records, methods and skills held locally rather than fetched. Covers loss of connectivity, loss of the person who knew, and a platform deciding to stop. |
| Shelter that holds | Structure that keeps temperature, air and radiation inside tolerable bounds without continuous input. Covers heat, cold, smoke, storm and space weather in one envelope. |
| People who have met before | A group that already knows who has the ute, the ladder and the medical training. Covers the organisational half of every emergency. |
Which is why the rest of this site is optional
The six are justified on mainstream hazard rates alone, and those return periods are set out on the calm. If the argument on the claim turns out wrong, nothing here was wasted. The evidence pages shape the specification, around timing and around how hard the shelter holds, rather than being the ticket in.
Two · the unit cell
A closed-loop food system in 38 cubic metres.
A twenty-foot shipping container holds about 33 cubic metres, so this is a container and a bit. It is specified as a volume and nothing else, which is the part that does the work later.
Inside it: hydroponic and aeroponic towers, insects, poultry, fish, microgreens, mushrooms and root crops, sized against each other rather than chosen separately. Fish water is the nutrient supply for the towers. Trimmings and kitchen waste go to the insects. The insects feed the poultry and the fish. Spent substrate goes to the mushrooms, and the root crops are the part that keeps without power.
Each part eats another part's waste, so what would be a disposal problem is the input that closes the loop.
A volume carries no site assumption inside it, which is why the specification is cubic metres rather than square metres of floor. The same module drops into a flat, an underground block or a hull with no redesign.
The first phase is three towers and 120 pots on a terrace: not a gesture toward a city, the first instance of the cell a city is made from.
Three · down
Subterranean cities, sited in sand and aquifer.
The allowance is about 100 cubic metres of dwelling per person: roughly a 40 square metre flat each at normal ceiling height. The full write-up sits at subterranean cities.
Sand and aquifer is the siting, one site condition answering three problems. Moving groundwater is a heat sink, which is what makes a sealed volume survivable: people and machines heat a space up, and something has to carry that away. The same water is the supply. The same water and overburden are the shielding.
Minjerribah sand carries zircon, rutile and ilmenite, which come out as product, and part of the remaining silica goes back in as structural liner. The spoil is the building, so the two largest numbers, digging and materials, are set against each other instead of added. The surface is left to recover above.
| Step | Figure | In the mind's eye |
|---|---|---|
| Island area | About 275 km² | Minjerribah, North Stradbroke Island. |
| Excavated to 100 m | About 27.5 billion m³ | Around 55 times the water Sydney Harbour holds. |
| Dwelling volume, 20 million people | 2 billion m³ | Under a tenth of the excavation; roughly a third once growing space, water, plant and circulation are added. |
| Depth for comparison | Derinkuyu, about 85 m | Cappadocia, cut by hand, and it held people. |
The density only sounds impossible in two dimensions.
Twenty million people on 275 square kilometres is about 73,000 per square kilometre, denser than any city on Earth. Spread across thirty-odd levels it is about 2,400 per square kilometre per level, which is ordinary Australian suburb, and a level is the unit a person lives on.
What that arithmetic is and is not
The volumes are arithmetic and anyone can redo them in a minute. They establish that the space exists, which is the objection usually raised first. They establish nothing about geotechnics, water table behaviour under a city, ventilation at that scale, cost, or whether anybody wants to live there.
Four · why mass rather than alerts
Warning depends on the damage being slower than the news.
Space weather forecasting works because the Sun sends its message faster than it sends its punch. The arrivals not built that way decide the shape of the shelter.
Light from a flare arrives in about eight minutes and twenty seconds. The plasma cloud that damages grids and pipelines crawls out at a few hundred to a few thousand kilometres a second and takes the better part of a day or three. That gap is the warning, and everything built at Kiruna and Boulder lives inside it.
For the fast half there is no gap. X-rays and gamma rays arrive with the picture of the event that made them, and radio blackout begins as the flare becomes visible. Energetic protons trail by tens of minutes, which is enough to move a crew and not much else. Anything travelling at light speed from the galactic centre has the same property stretched across 26,000 years, and no instrument changes it.
So preparation against the fast class cannot rest on alerts. It sits in the thing itself: equipment that keeps working without notice, records that survive without power, mass overhead already in place before the signal, none of which asks which cause arrived.
Five · up, and where the chain ends
The swarm is the terminus, and geometry puts it there.
A decentralised network holding continuous multi-angle, full-spectrum watch across the solar system. Designed and being simulated.
The chain starts at the fundable end. An hour of earthquake warning has one deliverable, a death rate behind it and a budget a grant can hold, and it runs on solar readings already collected, which is the case set out on the earthquake page. Sharper readings need more than one vantage point, and many vantage points held over time is the swarm, with the contested solar question falling out of the same feed.
Parker Solar Probe is one point sampling a plasma that is structured in space and varying in time. When its instruments record a change, nothing separates a structure the spacecraft flew through from a change that happened while it sat there. Four points define a tetrahedron, the smallest arrangement that tells a spatial gradient from a change over time, which is why ESA flies four Cluster spacecraft and NASA flies four MMS. Nothing like that formation has flown inside the corona, on the public record.
The Sun is the largest input nobody controls, and it is watched from essentially one spot.
Three conditions sit together. Every spacefaring power depends on the same star and none can move it. The gap is geometric, so no better instrument closes it. And cost per kilogram to orbit keeps falling. Weather satellites and satellite navigation took that shape: once the capability is cheap enough and the exposure understood, somebody builds it and the rest follow rather than stay blind. That leaves when, and who leads, rather than whether.
The design is roughly 1,500 to 2,000 satellites across the 200 most significant objects in the solar system, scaling from a four-satellite picket at a low-priority target to 50 to 100 nodes at the Sun. About the count in one Starlink shell, spread across a solar system instead of one orbit. No hardware, no costed launch path, no agency behind it. The instruments flying now are on the watch page.
Identical hardware, two different worlds
A swarm flown by one state is an intelligence asset: the feed is a national advantage, released at whatever pace suits its owner. The same satellites flown as an open commons are infrastructure, and everybody plans against the same picture. The metal does not decide which one it becomes; the founding partnership does. That is the argument for helping start it rather than waiting to become a customer of whoever does.
Six · the pattern
Define the cell. Own it. Replicate.
The same three-step move runs at 38 cubic metres, at 100 cubic metres a person and at four satellites, which is why the parts fit together rather than merely sharing a document.
Nothing in the stack requires a single owner, a single funder or a single decision, because the cell is the thing that gets built and the cell is small.
The honest state of it
Designed and being simulated: the food cell, the underground city, the swarm. At first-phase scale: three towers and 120 pots. Nothing is dug and nothing is flying.