Travel to other stars? A MILLION YEARS!!!

No, I don’t think so.

1. The Anecdote: A Flea in the Room

Amsterdam, sometime between 2012 and 2015.
A Mars One–adjacent event, part circus, part funeral. Back then Mars One was still alive, selling its dream of a one-way trip to Mars with the solemn absurdity of a late-night infomercial. The audience was a mix: space geeks, cynics, true believers, and a few strays like me who liked to pick fights about the future.

One of the speakers was Gerard ’t Hooft — Nobel laureate, heavyweight physicist, patron saint of Dutch skepticism. Brilliant man. Imposing intellect.

The subject drifted, inevitably, toward interstellar travel. Someone — maybe me — asked the question: what about the stars?

Gerard’s answer came down like a hammer:

“Travel to the stars won’t happen for millions of years.”

Not a speculation. Not a hedge. A flat, declarative statement.

And he wasn’t wrong, exactly. If you think in terms of rockets — giant ships burning fuel, crossing light-years in straight lines — then yes, millions of years is a generous estimate. Astronautics as we know it makes the stars unreachable.

But it struck me as a conversation-killer. A guillotine on imagination. And so, flea that I was, I piped up with a crude counter-thesis:

Don’t think of one ship limping across the void. Think of machines, replicating, seeding, colonizing every rock and snowball between here and Proxima Centauri. A cascade of factories, not a single rocket.

Gerard looked faintly irritated. He muttered, softly, “well, okay, that might work.” More swat than concession.

But that moment stayed with me. A decade later, it still nags at me — because in my bones I believe the flea was right.

2. The Corridor Isn’t Empty

The whole debate hinges on what you picture when you think of interstellar space.

Most people imagine void: sterile blackness, vacuum, maybe a stray atom of hydrogen drifting every cubic centimeter. A desert.

That’s wrong.

Astrophysics now tells us the void is cluttered. Sparse, yes. But not empty. It’s littered with the wreckage of planetary formation, a dark scrapyard stretching between stars.

Rogue Jupiters. Microlensing surveys suggest there are one or two Jupiter-mass planets for every star, drifting alone. That means 4–8 gas giants between here and Proxima.
Rogue Earths and Marses. Planetary models show early solar systems eject dozens to hundreds of rocky worlds. There should be hundreds of Earth- or Mars-sized rogues in just the four light-years between here and Alpha Centauri.
Rubble fields. The Oort Cloud is just our local fringe. Beyond it, the galaxy is thick with icy worlds: Plutoids, Sednas, FarFarOuts, city-sized bergs. The corridor could easily host trillions of icy fragments.
Dust and volatiles. Carbon chains, frozen organics, metal-rich grains. Thinly spread, but inexhaustible when mined systematically.

This isn’t desert. It’s an archipelago. A chain of stepping stones, each cold and lonely, but real estate all the same.

3. Replicators, Not Rockets

Gerard’s “millions of years” is correct in the idiom of rockets. One ship. One voyage. A straight line.

But that’s the wrong idiom.

The right idiom is replication.

Instead of a ship, imagine sending a seed factory:

Mining rigs.
Fusion reactor or solar array.
3D printers and smelters.
Control software.

The seed lands on an icy body — say, 200 AU out. It mines volatiles, prints structures, builds power systems. Within a decade, it produces another seed.

One becomes two. Two become four. Four become sixteen.

Each seed colony is not just a node but an accelerator:

Lasers to push sails outward.
Linear accelerators to fling reaction-mass packets at relativistic speed.
Shipyards to assemble more seed factories.
Telescopes to chart the corridor.

Within centuries, the “void” is filled with infrastructure. Instead of one fragile rocket, you have a relay network — a lattice of colonies, factories, lasers, and accelerators handing off to each other like runners in a relay race.

The corridor becomes a highway.

4. Building the Highway

Picture the sequence.

A seed factory lands on an icy rock 200 AU away (~30 billion km). Ten years later:

It’s built solar farms or fusion reactors.
It’s mining ice for hydrogen, deuterium, oxygen.
It’s smelting metals into trusses and beamlines.
It’s built a terawatt laser array.
It’s 3D-printed a dozen more seed factories.

Those factories launch further outward. Each carries sails. Each is boosted by the inner colony’s laser. Each lands on the next stone and repeats.

After a few iterations, you don’t have one colony — you have hundreds, then thousands. Each building lasers. Each firing beams forward.

Now add linear accelerators: kilometer-long magrails slinging canisters of hydrogen ice at 0.1c. Ships catch them with magnetic scoops. Suddenly, reaction mass is everywhere. Hard acceleration becomes sustainable.

Within a few centuries, the corridor bristles with light. Moons turned into machine shops. Comets into power plants. Whole rogue worlds crusted in photovoltaics.

A ladder across the dark.

5. The Math

Here’s where Gerard and I part company.

If you think linearly, his “millions of years” is right. But exponentials don’t care about linear intuition.

Case 1: Conservative (10-year replication, 200 AU steps)

Expansion rate: ~20 AU/year.
Alpha Centauri: 270,000 AU away.
Arrival: ~13,000 years.

Not millions. Still too long for human relevance.

Case 2: Optimistic (3-year replication, 1,000 AU steps)

Expansion rate: ~333 AU/year.
Arrival: ~800 years.

That’s closer to Charlemagne than to dinosaurs.

Case 3: Aggressive (3-year replication, 2,000 AU steps)

Expansion rate: ~666 AU/year.
Arrival: ~400 years.

That’s less time than since Galileo first saw Jupiter’s moons.

And this doesn’t include multipliers: once the inner corridor is dense, each new colony isn’t waiting for one laser — it’s being accelerated by thousands of arrays behind it, all firing in sync. Acceleration compounds.

The frontier fattens. The highway strengthens. Travel times collapse.

6. Historical Analogies

This isn’t fantasy. We’ve done this before.

The Polynesians colonized the Pacific by hopping from island to island. Canoes didn’t cross oceans in one shot. They built relays: food caches, stopovers, navigational chains. The void became a ladder.
The railroads. The American frontier wasn’t crossed by one wagon in one trip. It was filled incrementally — telegraph poles, train depots, repeaters. Each node strengthened the next.
The internet. Nobody built the whole thing at once. It grew by replication, node by node, until suddenly the network was everywhere.

Exponential cascades look impossible from the outside. Then they happen.

7. The Multipliers

Now add 21st-century multipliers.

AI and automation. Seed factories don’t need astronauts. They need self-repairing swarms of robots with adaptive algorithms. That’s not 2500 tech. That’s 2050 tech.
Fusion. Deuterium is abundant in comets. Fusion plants aren’t optional — they’re inevitable once you start mining deep cold.
Lasers. Terawatt lasers sound exotic, but they’re just scaled photovoltaics and optics. Once you have moons’ worth of surface to cover, it’s brute-force engineering.
Nanotech and materials. Light sails a thousand kilometers wide, engineered dust, self-assembling structures — all exponential technologies in themselves.

Every one of these shortens the cycle. Pushes replication time from decades to years, maybe less.

8. Objections and Counterpoints

Objection: Interstellar dust will shred ships.
Answer: True at 0.5c. But at 0.1c, with shielding and deflection fields, survivable. Plus, every colony in the corridor can clear paths ahead.

Objection: Politics will never allow autonomous replicators.
Answer: Politics won’t matter. Once one group launches, the cascade is irreversible.

Objection: Energy demands are insane.
Answer: Only if you think in Earthbound terms. A single rogue Jupiter offers energy reserves larger than humanity has ever consumed.

Objection: Too complex, too fragile.
Answer: That’s what people said about railroads, steamships, and the internet. Complex systems bootstrap.

9. Verdict: Who’s Right?

Gerard’s “millions of years” was respectable. It was the cautious, conservative, 20th-century physicist’s answer. The kind of answer that avoids embarrassment.

But I believe it’s wrong.

The corridor isn’t empty. It’s full of stepping stones.
The right vehicle isn’t a rocket. It’s a replicator.
The right timescale isn’t millions. It’s centuries.

Charlemagne to Alpha Centauri. Galileo to Proxima. That’s the horizon.

And here’s the irony: Gerard muttered “well, okay” not because I persuaded him, but because he knew where my logic pointed.

Exponentials don’t ask for permission.

10. Conclusion: Not Millions

The flea’s counterargument is this: interstellar travel isn’t about a heroic ship. It’s about a cascade of machines colonizing the corridor.

Do that, and the galaxy doesn’t open in millions of years. It opens in human-historical time.

Less than a thousand years. Maybe less than 500.

Not optimism. Not fantasy. Just math.

FASTER!

Yes — faster is possible, but it means stacking the deck with more aggressive assumptions. Right now your “corridor model” assumes seed factories replicating every ~3–10 years, stepping 200–2,000 AU per cycle. That’s already aggressive. But let’s play with levers:

11. Shrink the Replication Cycle

Instead of 3–10 years per colony, aim for months to 1 year.
How? Fully robotic, pre-designed modules instead of building from scratch. Think: a ship arrives, unpacks “seed kits,” self-assembles in a few months, and is operational almost immediately.
This is like going from early human settlers with axes to modern prefab container homes. The cycle collapses.

Impact: 1-year replication with 1,000 AU jumps → Proxima in ~270 years.

12. Push Acceleration Beyond Solar Sails

Right now, sails + corridor lasers give you ~0.1c.
Add linear accelerators firing pre-packaged reaction mass at 0.3–0.5c, which ships scoop and use to push faster.
Add fusion torchships that burn deuterium scooped from comets — acceleration doesn’t stop when the sail runs out.

Impact: Cruise speed 0.2–0.3c → cut Proxima travel from ~40 years to 15–20 years per long leg.

13. Parallelization Instead of Serial Expansion

Don’t send one wavefront, send thousands simultaneously in different directions.
Most fail. Some succeed. Survivors seed their zones.
This looks wasteful, but replication turns failures cheap.

Impact: Corridor matures not in series (one after the other), but in a mesh, accelerating density and redundancy.

14. AI-First Industrial Base

A critical bottleneck is how fast colonies “invent” infrastructure.
Replace invention with pre-loaded AI blueprints: each colony knows how to bootstrap fusion plants, lasers, accelerators instantly.
Instead of decades of R&D, it’s plug-and-play engineering.

Impact: Drops colony development times from decades → months.

15. Use “Fast Movers” as Couriers

Not all ships need to replicate. Some are just relays: ships carrying high-tech components from inner colonies to outer ones at 0.3c.
Outer colonies don’t waste time rediscovering complex machinery; they’re resupplied by couriers.

Impact: The outer frontier doesn’t stagnate — it’s constantly “fed” with parts. Expansion accelerates exponentially.

Aggressive Model:

Replication cycle: 1 year.
Step distance: 2,000 AU (using large sails + high-power beams).
Cruise speed: 0.2c with hybrid sail/fusion.

That’s 2,000 AU/year expansion effective rate.
Proxima at 270,000 AU = ~135 years.

So yes — with extreme assumptions (AI-designed prefab colonies, fast movers, and hybrid sail + refueling torchships), the corridor could plausibly reach Proxima in under 200 years. That’s not millions. That’s not thousands. That’s two human lifespans.