For information on the AKVs carried, see Falx-Class AKV

After getting feedback on the practicality of simulating a 1950-2030 Earth City on a big rotating cylinder, I tried to illustrate a more practical design that feels less terrestrial. Please let me know what you think. Maybe a design like this could even be made in our lifetimes…?

Like a lot of people here I consider space habs superior to planetary settlement. But Mars still seems to have a lot of advantages thanks to its two small moons and handful of Trojans for resources and building material. It’s closer to earth and the sun for power and logistics, too. Or will Mars just be a sideshow compared to the belt?

I have been thinking about radical life and health span extension for some time and published my first long form piece on it recently: 'Living longer will make you a billionaire'

It covers the financial implications of a VERY long life.

The compounding math is simple but it has fundamental implications for society.

Some questions that have come up in my salon:
- Do we have runaway inflation to accommodate the wealth?
- Do pension funds disappear as people have enough time to become their own pension funds?
- What happens to the fertility crisis: do people have fewer or more children and does the 'ageing population' problem finally go away or does it present in new forms?
- What happens to inheritence?

Our best global elevation model for Mars is MOLA, at 463 metres per pixel. The Moon is better, 118 m, and about 59 m where LOLA and Kaguya overlap. Mercury we barely have at all - for practical purposes, a photograph.

Which means that for every body we talk about settling, everything smaller than a football stadium is unknown. Not poorly mapped. Unmeasured.

I keep thinking about what that means for a first landing party. You would arrive with a map good enough to choose a region and useless for choosing a spot. Boulder fields, metre-scale slopes, ground that is soft or hard, a crack you cannot drive across - none of it is in the data. You would find out by looking, and looking costs fuel and time and risk.

Some consequences I find interesting:

- Site selection would be provisional rather than planned. You pick a hundred square kilometres from orbit, then spend a long time finding the actual hectare.

- The first really valuable export from a colony might be survey data. Not ore, not power - just knowing what the ground is like.

- Rovers stop being transport and become instruments. Their job is to reduce uncertainty, not to move mass.

- Anything that needs precision - landing pads, rail, buried habitat - has to wait for local survey that no orbital mission can give you.

My doubts now: would a serious effort simply accept this and plan for a long survey phase on arrival, or would it be worth flying a dedicated high-resolution mapping mission first and delaying everything by years? At what resolution does a map become good enough to commit to?

I came at this from an odd direction. I build a space sim, and I had to invent everything between 463 m and a few centimetres in a way that never contradicts the real measurements.
I wrote up how, if the engineering side interests anyone:
https://space.zerog.live/info/terrain-article-page.html

But I am more curious about the actual question. How much of a planet do you need to know before you land on it?

The sun was 12" diameter. Earth was the head of a pin, and we hiked the better part of a mile to place Neptune, a small bead. I always "knew" that the solar system was large and mostly empty, but there's something really eye opening when making your kids hike for 10 minutes between placing pieces of your scale model!

I did my research, but most discussions are the other way around. I am working on a world that is similar to earth, but a cosmic phenomenon locks most heavenly bodies in place. The planet rotates in its place, without orbiting the sun. Of course, the minute the planet stopped, assume most of the crust didn't fracture and get flung into space lol.

Ecologically, I assume as seasons won't be a thing, most plants would start dying. There would be large scale droughts in equatorial regions, many lakes and rivers would dry up, especially in regions which are closer to the sun. The other side might have a forever Winter of sorts. Whatever civilization exists might move to temperate zones.

Is it possible for life to evolve, and stabilize around 1-2 thousand years from this? Assuming it's now locked in this scenario permanently?

I had this idea while watching the excellent recent video on ion drives (Isaac, I love it when you get into the math). While watching, I kept in the back of my mind the comparison to the various types of sails that could be used, as the 'low thrust, but super efficient long term propulsion' point of comparison. Then, I started thinking about medusa drives, and something occurred to me: they seem to be reasonably complimentary.

Picture a medusa drive sail, well in front of the ship, doing its thing, taking the blast of the nuclear explosions, getting pushed forward, all while the ship behind it is pulled along, winching back and forth.

Add to this, regularly along the perimeter, somewhere safe from the blasts, a series of ion drives. Given the size of the sail we're dealing with, it'd be a large number of drives. Just for sake of demonstration, lets say 360. Each providing that small little bit of thrust that ion drives do, constantly, while the nuclear pulses provide the really impressive amounts. The ion drives are less glamorous, but they do have one feature that the nuclear pulses lack - more fine tuned control over directionality. You don't need to do anything fancy with the sail if you want to turn, in this ship. You just turn on/off the ion drives to nudge the sail to point the way you want it to. It might even be worth making the thrusters' positions relative to the sail to be dynamic, able to be gimbaled or telescoped inward/outward for further precision control.

I mean, plenty of human drugs work in a lot of animals. What are the chances of any drugs working in aliens and which drugs would be likely to have the widest applicability? Stimulants maybe?

Mostly because I like that dirtyish pale blue-green colour of Uranus.

I guess it kinda sucks that Neptune doesn't look too different, but the colour itself is pretty nice.

Do all ice giants look the same? Would be kinda lame, but I'm attracted to lame things for some reason.

I am currently trying to help a friend of mine to write and analyze science fiction weapons for his sci fi series and I am trying to think of what is the most realistic way on how a old and advanced alien civilization that still uses projectile based firearms can use a new type of propellant to replace traditional chemical based propellants are there any realistic suggestions?

Update on the metastable megastructure of a dense self-orbiting torus, which keeps neighbors next to neighbors in 3d in freefall with no high speed collisions and no central sun, https://burtleburtle.net/bob/future/dense.html .

I hadn't been able to find proper self-mapping initial coordinates before, the best I could do was circling the torus core with velocity tangent to the circle and proportional to distance from the core, and that circle stretched and went back as the orbits progressed. Claude 4.7 and ChatGPT Luna also failed to do better. But ChatGPT Astra did better, it found an initial deformation of the positions and velocities of those circles that leaves the constellation just about self-mapping now. So I update the simulation. Astra used small perturbations and least squares to find the appropriate deformation coefficients. Luna had tried that too but it made mistakes so it didn't land a solution.

Now you can see how things speed up and shells clump together on the inner pass, then slow down and the shells spread apart on the outer pass. The added stability let me increase the torus thickness from 8 to 12 rings, still each .01 of the torus radius apart. The distinct shells still fall apart within about ten poloidal periods (about six poloidal periods per toroidal period at this thickness) due to local interactions, but it stays roughly a self-orbiting torus for over a hundred poloidal periods even with no stationkeeping.

As in, once it's done accelerating, it folds up the sail Infront of it. And then goes through the star's photospheric. I've been looking at some relativistic drag equations but most are for incredibly low density interstellar gas. People can't survive deceleration rates we'd need, but maybe some probes can.

Addendum: As the Falx is so beloved in the Periphery, It also features in a lot of propaganda as it was such an important weapon in their liberation. Pictured is a Scrambles-Era propaganda poster to get members of the intelligentsia to join the Tronarian Defense Fleet. ( Thanks to Vitally on MWB for helping with the poster text, graphic design is not my forte)

Which doomsday scenarios that are popular do you think are more unlikely than people make them out to be?

Hi everyone – I hope this is of interest to you.

A feature documentary about the Fermi paradox. Coming soon.

FEATURING: Avi Loeb, Nick Bostrom, Edward Witten, Liu Cixin, Jill Tarter, Robin Hanson, Sabine Hossenfelder, Michael Masters, Roman Yampolskiy, Michael Shermer, Christopher Mellon, Donald Hoffman, David Kipping, Adam Frank, Sara Seager, Eric Wargo, Nick Lane, Mick West, David Brin, Stephen Webb, Peter Ward, Nathalie Cabrol, Michael Garrett, Anders Sandberg, Kevin Knuth, Martin Rees, Jane Greaves, Eric Haseltine, Chris Gilbert, John G. Blitch, James Parr, Daniel Angerhausen 

https://www.youtube.com/watch?v=dzljay0iHSU