Sand Baths are they Practical for People on Desert Planet

Question

On a (colonized) fallen world humans have been pushed to the brink. The planet is a massive desert world with no body of water on the surface, and no rain fall. The only way to get water is from the aquifers underground but even they go dry leaving the settlement to die shortly after.

Society is still advanced in a way, but is more tribal/feudal in nature. Most of the inner towns have 1700 tech level (most don't have access to this and are stuck with medieval tech); war and lack of infrastructure stop them from ever going past this point.

So water being so hard to get, is rationed and protected. Even drinking it greedily can get you killed. the center that hold the most water is straggling to keep up with demand and war has broken out, but drinking water is still available to most people. water is too precious to be wasted bathing, so how would one wash themselves?

Sand baths seem to be the next logical step, but I don't know if it could be a long term solution to the problem. I also don't know how to build one; I was thinking a bath house (sand house) like setup for the whole town to use. Reason for this is I don't think just regular old desert sand would work (a type of sand best suited for washing) but I could be wrong.

The Question: Sand Baths are they Practical for People on Desert Planet?

So any ideas would be great, if you come up with a better idea on how they could wash themselves don't hesitate to answer, just keep in mind the tech level and they can’t build anything fancy. With it being war time trade would be difficult as well.

Answer 1

Part of the problem you are addressing is objectively measurable, part is strongly cultural dependent.

The objectively measurable part is "how can one remove sebum/dead skin out of their body?", and for that sand and oil can be used. The mixture of sand and oil was commonly used by athletes during the Olympic games (the old ones, not the sponsor flooded games we have today), and taken away from the body surface using a crescent shaped metal tool, called strigil.

The strigil is a tool for the cleansing of the body by scraping off dirt, perspiration, and oil that was applied before bathing in Ancient Greek and Roman cultures. [...] The standard design is a curved blade with a handle, all of which is made of metal.

Strigils were commonly used by individuals who were engaging in vigorous activities, in which they accumulated large amounts of dirt and sweat on their bodies. The people who used the strigil included athletes, the wealthy, soldiers, and more. However, wealthy or prestigious individuals often had slaves to wield the strigils and clean their bodies, rather than doing it themselves

Something similar is what you can use for your world.

The part which is strongly cultural is how to deal with the body odor. The concept of "smell" is strongly dependent on the cultural context (what is a smelly body to a group of stock exchange agents or to a group of shepherds is different), so we have no way to tell how this will play in your universe, or, better, you have freedom of bending this to your needs.

Moreover, if water on this planet is so scarce it means that also the atmosphere will be pretty dry. A really dry atmosphere means that any body humidity will be quickly gone, and without body humidity bacteria will have an hard time growing. And most of a body odor comes from the work of those bacteria.

Answer 2

A different idea: wash with petrochemicals. Your dry world might be rich in alkanes. Low molecular weight liquid fractions like hexane, kerosene or the mix we use as gasoline are all excellent cleaners and degreasers. Some of us may have turned to gasoline to clean off oily hands and it works great. In your society they could use the freshest new distillations for personal hygiene, the second use for laundry and then burn the used alkane (and captured grease and dirt) for fuel.

When gasoline was newly cheap and available, it was widely used for washing. Dry cleaning still works on much the same principle.

No smoking!

https://www.youtube.com/watch?v=zMku2mhrDeo

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addendum - remember combustion of alkanes yields water and CO2: CH4+O2 -> CO2 + H2O. That is good water. Capture it with a condenser circuit and have a drink.

Answer 3

Answer is: in the end we will get used to our own body odors. Just think that Europeans used to spend long periods without taking baths and still living in crowded cities in precarious hygienc condition. At least, here there wouldn't be the problem of overpopulation. Other than that, sand makes for a great all-body scrubber, so it would be highly recommended.

Answer 4

You might be interested in thinking about how a world like this would happen. It might be fund.

Atmosphere with lots of oxygen (and I guess nitrogen), but not much hydrogen. Silicon-dioxide deserts covering most of the surface, no surface water, no oceans.

I'm guessing that the ground water is very salty. Like our salt oceans or maybe more like the Dead Sea. In our world lots of salt goes to the oceans. In this world, there isn't much reason for it to ever leave the underground ocean. Unless you want to make the world stranger and have it not have much salt.

Humans come to this world and they need CHON. They can get O2 and N2 from the air. They can get H2O from the groundwater, once they remove the salt. Where do they get the carbon? It has to be on the rocky surface. Maybe graphite mines? Carbonate rock? A little bit of CO2 in the air?

Humans need a lot of energy. They can use solar panels for sunlight, or maybe they have fusion generators or something. If they have that much energy, they can grow their food in labs. Or more likely they will actually grow plants. Why expose them to harsh conditions on the surface? Grow them in tunnels with artificial light. Pump out the moist air the plants respire and extract the water to use again. Probably cheaper than distilling out salt from fresh-pumped groundwater. Maybe it would make sense to have greenhouses and recycle the water and air.

Maybe wasting water results in some of it getting into the atmosphere faster than it can get back to groundwater. You don't have enough water to have clouds and raid. The water that humans use and fail to recycle either goes back to groundwater or elsewhere, so your water table is dropping. Also, cities keep pumping water and they hold onto it as well as they can. The more they collect, the less remains. Groundwater would move laterally toward cities, leaving less for surrounding areas.

If you're going to recycle your water anyway, why not wash with it and then recycle it? You have to recycle it. And energy is cheap.

But if you want to wash with sand, I suggest a quick scrub with one variety of sand for exfoliation. Then a leisurely scrub with powder to adsorb whatever it will adsorb. Then a quick scrub with a different variety of sand to mostly scrape off the powder. I don't know whether you'd want coarse sand for one scrub and finer sand for the other, but marketing and esthetics dictate there will be two kinds.

Answer 5

1700's technology.

It's a weird world. You have fresh water that can be reached by shallow wells. Probably high winds so you can use windmills to pump the fresh water.

You desperately need water to irrigate your plants. You grow some plants that have very deep roots. So for example alfalfa roots can go 100 feet deep, and the plant can survive for 20 years or more. You can cut it back and carefully feed the leaves to food animals, or harvest the seeds and sprout them, etc. When you have to replant then the seedlings need to be irrigated until their roots are deep enough.

Grow various drought-tolerant trees with edible fruits and nuts. Date palms. Olives.

Plants extract water from the ground and evaporate it into the air. It tends not to come back, because there isn't enough water in the air to rain. Water slowly returns to the soil by condensing into on the coldest nights and finding its way lower before the sun's heat can evaporate it again. Agriculture results in water tables going lower, but there's no alternative to growing food.

Food is expensive. A minimum of food animals for rich people. Water is expensive. A person who publicly wastes water -- for example pours out surplus water onto the ground -- may incite violence. They wasted water that they could have given to someone who needed it.

So yes, sand baths. Sand, powder, other sand. Richer people could rub their skin with vegetable oil too. Less rich people could do it once a month. Poor people never.

Waste product -- dirty sand. Dump it downwind of anywhere important. It dries out and powdered skin blows away downwind but does not rot because it's too dry. It blows away. Nobody wants to live downwind of a city even though that's the cheapest rent.

Similarly with human wastes. Rub your butt with sand. Waste products get carried out of the city by people with low-paying jobs, and dumped downwind. Maybe buried, but after awhile they get unburied. Dried to powder, abraded by moving sand, blown away.

The water table is dropping. Everyone is getting poorer. But they aren't poor enough yet to keep the population from growing, so everyone gets poorer faster.

Answer 6

Given that the city administration is willing to create communal sand houses for both the elite and lower class, With minimal available technology, then the houses could be something like this:

1. Simply rub your body with sand (same as the basic idea).
2. Go through a series of pressured air jets, to remove the excess sand from the body. (Similar to industrial dusting, where employees have to clean themselves before working in a dust free environment)
3. Then a small stroll through a UV chamber to kill of Bacteria. (Protect your eyes though)

This UV Chamber can have some features like (though I am not technically sure about this):

• Low power UV, so that skin is not damaged.
• Conveyor belt, so that you don't have to walk with your eyes covered.
• Length of 3-5 meters should be fine.
• It can have limited access to elite class only (Another reason for war)

Now I can think of 2 problems with this, that it won't be good for babies and hairs. This city must be using some sort of fruits and vegetables, so from their remains, you can create some oil to gently clean babies and nourish your hairs. (again only accessible for elite class)