164 votes

What is the utilitarian purpose of artificial waterfalls?

Low-tech climate control: the waterfalls fill the air with spray, which evaporates off and cools the populace. The Romans used to achieve a similar effect with fountains.
Chronocidal's user avatar
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125 votes

What is the utilitarian purpose of artificial waterfalls?

Still water is heaven for proliferating algae, bacteria and annoying insects like mosquitoes. A large city with large bodies of still water is a recipe for plague spreading. Having water on the move ...
L.Dutch's user avatar
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70 votes
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In a post-fossil fuel economy, what could natural gas pipelines be used for?

They can used for underground power and communication lines, as a replacement for overhead lines. The reason why overhead lines are still prevalent in America is due to the initial cost of ...
Giter's user avatar
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70 votes

What is the utilitarian purpose of artificial waterfalls?

Energy storage. You use a form of energy generation with unreliable or periodic output. As a form of energy storage you pump water up into a nice big reservoir when you have surplus, then power ...
Joe Bloggs's user avatar
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60 votes
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How can a barren island state comprised of morons maintain positive GDP for decades?

not going into the discussion on "does IQ really measure intelligence or not?" Putting in practice the word of Koalemos is deemed the highest honor in their society, therefore those with the ...
L.Dutch's user avatar
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59 votes

How can one empty a cesspit with medieval technology?

I would suggest composting. Design the waste water routing (trenches or plumbing) so that they can feed into one of several cesspits, then change which pit is fed on an annual basis. After each pit'...
Henry Taylor's user avatar
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59 votes

What is the utilitarian purpose of artificial waterfalls?

You're looking at it backwards. Nobody added artificial waterways to a city. They did what they had to do to support building a city on top of existing waterways. Human settlements naturally spring ...
bta's user avatar
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56 votes
Accepted

The first McDonald's restaurant on Mars

A (local) population of about ten thousand people should be enough. In my opinion there are three factors here. Is there enough need for a restaurant? There seem to be around 14.000 McDonalds ...
mlk's user avatar
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50 votes
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How to safely derail a train during transit?

The Fast and the Furiously Crazy Since you've eliminated the sensible solution (bypasses or double tracks), let's go with an insane one! All your trains have rail tracks running on top of them and ...
Cyrus's user avatar
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49 votes

How can I prevent the invention of skyscrapers?

Restriction for religious and political reasons No building should be higher than the local religious, historical, political or symbolic buildings. Such restrictions existed in the past, be it for ...
Kepotx's user avatar
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43 votes

In a post-fossil fuel economy, what could natural gas pipelines be used for?

It is actually a trick question, in a fully renewable energy economy natural gas pipelines will continue to transfer natural gas produced from renewable sources. Natural gas normally comes from ...
Josh King's user avatar
  • 24.8k
41 votes

How to safely derail a train during transit?

Two trains become one. On the track there is a train heading in one direction at 100 km/h and a second train heading towards it at 200 km/h. You do not specify the distance between them. If there ...
Willk's user avatar
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41 votes
Accepted

Could earthquake cancellation work?

what challenges beside engineering and cost would make such a machine impossible to realise? The same reason for which you have noise cancelling earphones but not noise cancelling speakers. ...
L.Dutch's user avatar
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41 votes

How can I prevent the invention of skyscrapers?

Change the ground I once heard it said that skyscrapers represented the mountain beneath your feet. What that meant was that skyscrapers require rock-hard bedrock in order to be built, or at the very ...
Halfthawed's user avatar
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40 votes
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How can we enable a centaur to climb between different floors?

it is going to be a challenge for a horse to use a staircase since they can't climb down a flight of steps without tripping and fell due to their anatomy. (copyright status unclear, thanks pinterest) ...
Starfish Prime's user avatar
39 votes

Can there be a long-range railway system without industrialisation?

Apart from the high speeds, I think this might be possible. Diolkos was "a trackway paved with hard limestone with parallel grooves running about 1.60 metres (63 in) apart" near Corinth, in Ancient ...
MrBunsy's user avatar
  • 498
38 votes

Is there any organization to a shantytown of storage containers?

Let's take a look at Kowloon Walled City - closest real world analog of what you're asking. Government There used to be somewhat competing gangs. There was, generally, a truce between them, and ...
Mołot's user avatar
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35 votes

How can one empty a cesspit with medieval technology?

It is pretty simple, and this is actually how it was done until about 50 years ago in the region where I come from, where most of the houses had no sewer at all, but only a small cesspit. The method ...
L.Dutch's user avatar
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34 votes
Accepted

When my city is miles high, where do the utility lines go?

Sewers still work the way they always did The DWV (drain-waste-vent) system in a high-rise building is actually quite similar to that found in a house -- it's simply bigger! The principles (gravity ...
Shalvenay's user avatar
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33 votes

Could earthquake cancellation work?

This technology, called "Tuned Mass Dampers", is in practical use for decades, see the corresponding Wikipedia article. In skyscrapers, they do exactly what is asked for: changing the resonant ...
orithena's user avatar
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32 votes

Can there be a long-range railway system without industrialisation?

The way that preindustrial / early industrial people achieved what you want is with canals. Depicted: Barton aqueduct taking the canal across a river. England had hundreds of miles of canals, and ...
Willk's user avatar
  • 304k
30 votes

How can I prevent the invention of skyscrapers?

How do we make the impossible, possible? We begin by explaining why it's impossible. WB sees a lot of questions of the form, "how do I stop X from ever happening?" X can be a technology, or an ...
JBH's user avatar
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27 votes
Accepted

What's the most convenient time of year in the USA to end the world?

Mid Spring Around late April the last freezes will have passed through the U.S.. It will be possible to remain outdoors with little protection for seven months from this time. Farmers will have ...
James McLellan's user avatar
27 votes

Alternatives to batteries for "residential" power?

Pumped Storage If your family has significant resources, and access to two water reservoirs (One at a high altitude up the mountain, the other lower down), then they could have a custom pumped ...
MadScientist's user avatar
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26 votes
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How can a mechanical clock be powered by wind in a reliable, constant way?

Wind turns windmill, windmill lifts weight, weight powers tower clock. Use two weights to have power when the windmill is lifting one of them. This obviously decouples the strength of the wind from ...
AlexP's user avatar
  • 87.5k
26 votes

Where is the best place to trick a vampire into "crossing open water"?

Water heater check it out... source Sucko the New Vampire is reading War and Peace on the potty, as is his wont. Little does he know that directly below and separated by only 6 inches of pressboard ...
Willk's user avatar
  • 304k
25 votes
Accepted

Logistics of a steam-powered subway system

Make it steam-powered, but not in the way you're thinking. Cable-Car Subways In your steampunk world, clever inventors are going to realize that inhaling the effluvia from coalsmoke and being rained ...
jdunlop's user avatar
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24 votes

How can one empty a cesspit with medieval technology?

Actually, cleaning of cesspits and latrines was a well rewarded, if not we'll respected job since Medieval times to 19 century, you might want to consult this article: https://en.m.wikipedia.org/wiki/...
user61244's user avatar
  • 1,130
24 votes

How can I prevent the invention of skyscrapers?

Catastrophic Failure In the early 20th century, airships as a means of travel were on the rise. That is, until the fateful crash of the Hindenburg shocked the world. This marked the abrupt end to the ...
Zibbobz's user avatar
  • 4,286
23 votes

Is there any organization to a shantytown of storage containers?

There's a difference between the trendy places that make an apartment building out of shipping containers (which is what you have as your picture) and actual slums. While there were patents for ...
Erin Thursby's user avatar
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