farmerben

The kilopower reactor generates 10 kW of power with a HEU core the size of a toilet paper tube. That's only 13 horsepower. That's lawnmower scale. Not big enough for serious digging in my opinion. I'd say you want at least 30 hp to move 1000 lbs of material at a time even with the lower gravity. However you have discontinuous demand for power in a digging machine, so with batteries it balances out. At this point we don't have great battery powered tractors on Earth. https://en.wikipedia.org/wiki/Kilopower

It is affordable and safe enough to ship HEU from Earth to Mars. What is less affordable is producing batteries on Earth and shipping all that mass to Mars. I have no idea how the Martians will make batteries, but that seems like something way down the list of industries they will be capable of.

If you can dig into solid rock, it should be possible to seal the air in with a very thin layer of vinyl which you can mix and spray on with very simple equipment, similar to the way they build fiberglass boats. This will work even on jagged and fissured surfaces left by tunneling with dynamite. You can bolt your nice outer wall to the jagged rock and then fill the gaps with epoxy and fiberglass.

The danger of cosmic rays is much exaggerated. Lots of people will average 2 hrs per day exposed to the full Martian surface and be totally fine. Our beets and cabbages will grow in the 30 hour Martian day for their brief lives and not care at all about the higher dose of cosmic rays.

Bulldozing dust along the sides of a rectangular vaulted arch is a very good method. A good conveyor belt could deposit dust on top of a structure without crash loading it as much as a bulldozer would. Digging is not as easy as we wish it might be. The best first base is to find lava tubes and work on just sealing them. When you want to dig into solid rock, which you will, its best to start at the base of a cliff and dig in, much easier than going down first. It works out about the same because water is mostly oxygen, and oxygen has basically the same shielding as nitrogen. When you get to discuss the shielding or rock vs metal, the simple mass comparison might not be sufficient.

1 atm of pressure is increased every time you dive 33ft under water.

More like 10m

Pavonis Mons having a crater 47km across and 5km deep could support 15 million luxury cliff dwellings (5m tallx 10m wide). Meanwhile with our standard agricultural dome is 100 m2. So that's up to 70 million dome units in the caldera of alone. With extremely intensive layered vertical farming, you can probably feed one average human on 100 m2. So the floor of the caldera could potentially feed 70 million people. The balconies add 10% to growing space, but realistically we use more than that of the caldera space for non agriculture. A few mining boomtowns may spring up on Mars if we find rich veins of ore. And the asteroid miners will purchase food from Mars in preference to Earth if they can for potentially 10% of the haulage costs. Yet it makes little sense to develop agriculture elsewhere besides Pavonis Mons, since it is the best natural spaceport on Mars being equitorial high altitude and close to valles marineris. You will still require vast amounts of nuclear energy. The layout for primary logistics and communications are obviously hub and spoke.

Another good reason to develop a crater 47 km in diameter 5 km tall. You can have a million glazed balcony/greenhouses, attached to a living room with horizontal natural light, attached to deeper rooms for sleeping etc. If citizens get rich they could afford to burrow farther and carry the material out their front door. I would agree you need central planning for the first 5000 people or so. But to reach a million people (and not be dystopia) you need elements of capitalism.

That looks pretty dystopian to me. Cities are organic things that need to grow, decay, and regenerate... If the whole thing is the same it will all go into decay at the same time. I think you must have private property in which people own, choose, and make their own stuff. I think rich martians should have their own cavernous house and 100m2 greenhouse

Pavonis Mons is my favorite location for a Mars base. The caldera is 47 km across and 5 km deep. I wonder if it is possible to glaze over something that large. More likely you would have many small greenhouses on the floor of the caldera. And a ring of habitable city carved into the cliff faces. Then every house could have a horizontal window allowing sunlight, yet very good radiation shielding naturally built in. A spaceport sits atop the caldera just to the south, and a road leads east the Valles mariners.

I know a roofer who shingled a geodesic dome "once". Key word "once".

What is the optimal size for domes and similar structures on Mars or on the Moon? How would you approach the problem? What are the constraining limits? 1. Wind loading or other structural parameters on Mars, not applicable on the Moon. 2. Manufacturing limited. Being easier to manufacture a small sheet of glass than a large one, and so on for other components. Pyramids would actually be much simpler and stronger to build than domes using aluminum and glass. 3. Transport limited. Components have to fit inside a fairing for interplanetary travel so that sets the size constraint. 4. Human scale. If you can fit everything you need into 100m2 then why build bigger? Even for agriculture on Earth it's usually better to build several small greenhouses rather than one huge one. 5. Constrained only by imagination and budget. Flying and jumping sports might become the most popular activities on the Moon. So a humungous aerodrome is desirable for purely entertainment purposes.

Robert Zubrin says that if we warmed Mars by 10 degrees C, then CO2 would outgas from the soil raising the pressure to almost 1/3 atm.

How warm could you make Mars? Enhanced global warming with CFC gasses can help you reach Mt Everest level environments according to Zubrin. But, what if you wanted to go warmer than that and become downright tropical. Can you do it with greenhouse gasses?

I have two major objections to the multi-verse theory as espoused by people like Sean Carroll. A few times I have talked with physicists who believe in the multiverse and they dismiss my objections as if I just don't know what I'm talking about and am not making a real point. These are my two arguments. 1. The set of Pythagorean right triangles is an cardinally countable infinite set. If anything possible can be found in an infinite set. then anything possible is a Pythagorean right triangle. The same argument works for uncountable sets. The length of sides and angles of triangle is uncountable. Therefore everything is a triangle. 2. In optics a typical sheet of glass will allow 95% of photons to pass and 5% to reflect. It depends on angle and a few variables but we need not go into all that. The same result is obtained if you send one photon at a time into the glass. Every photon splits the possible universes in two, one in which it reflected and one where it didn't. There are only two possible states yet one of them appears 95% of the time. So whenever a photon hits glass does the inverse split in 2 or does it split in 20 so the equation is balanced and we have 19 universes in which the photon was transmitted and 1 universe where it didn't?

A human would have a hard time turning around. A cat can do it. Basically touch your toes with your fingers then roll around to a full backbend. Dunno a human that can do it, almost though.

Within a few years we could have a solar collector near the south pole in perpetual sun, 20 km away from the known ice fields. Human exploration will include looking for lava tubes. And then figuring out if lava tubes can be sealed to create habitat. One method of searching for lava tubes is to set up a grid of seismometers and set off some dynamite. That could generate an acoustic subsurface map.

On the Mississippi river the towboats do not stop to refuel. Tender boats come out and refuel them with diesel in motion. I wonder to what degree you could do the same thing on batteries? The big towboats use about 10,000 kW of power.

Given that weight is a big issue and the square cube law. This could be a partial solution for ships.

What is the difference between crushed glass and sand? Can you use them interchangeably in concrete? If you were to spread crushed glass on the environment, would that be worse than spreading sand?

Another idea. What about using wood? Very little wood is "wasted" at saw mills, but more of it goes into fuel than engineered products. The engineered wood products require process heat after all. Anyway when you saw lumber anywhere from 25-50% of it ends up as wood chips and they will oxidize eventually one way or another.

Do staircases work in Martian or Lunar gravity? So do you want much larger steps to leap up to, or are staircases governed by the flexibility of the average person and need to be the same size?

i made it to lvl 8. not easy

Don't waste my time on another LEO station if it doesn't have a centrifuge.