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An adventurer (named Moses, for humor's sake) finds a clear pool of water deep in a cave. Upon taking a swim, he finds at the bottom of the pool is a mystical stone that eternally puts out water, seemingly from nowhere. Hailing from the desert, he realizes what an amazing find this is!

Moses tries to think of a good way to transport the stone out of the cave, across many leagues of rough terrain, and deposit it where he can safely monetize its output in his desert city.

Constraints:

The stone artifact is heavy and largish, let's say a cube of about a meter's size (but it doesn't matter too much). This would make it weigh something like 2500 kg.

The stone is located about a meter below the surface of the pool of water. You could easily stand on top of it and still have your head above the surface.

It puts out water slowly, like a small mountain spring. Unfortunately, this ability can't be turned off, so it can make travel very, very wet.

The world has a limited technology level (Renaissance era-ish) and, more importantly, the character has a limited budget!

Bonus points if you give special attention to how the properties of the artifact affect (for better or for worse) your proposed travel technique.

How can Moses transport the magical, water-producing artifact?

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    $\begingroup$ If you break up the artifact, does each piece continue to generate water? I see huge profits if so. $\endgroup$ – Frostfyre Jun 24 '15 at 2:17
  • $\begingroup$ I would suggest you freeze a small region surrounding the rock since ice is less dense than water the rock may floats then move it to shore and start polishing it into a sphere and roll it back home! as for freezing I intend to leave it as a homework for readers. $\endgroup$ – user6760 Jun 24 '15 at 2:21
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    $\begingroup$ @Frostfyre I didn't think of breaking it up! I don't... er, "the character" doesn't know if the artifact will continue to work if broken. So that's a gamble at best. $\endgroup$ – Thane Brimhall Jun 24 '15 at 2:22
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    $\begingroup$ Wait, if this artefact has been producing water (albeit slowly) for a long time, why isn't it at the bottom of a huge lake? Unless it is a recent invention, this thing would have long ago drowned everything around it because of its "can't be turned off" properties. $\endgroup$ – Theik Jun 25 '15 at 11:10
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    $\begingroup$ Some sort of overflow or outlet. It's probably the start of an underground river! $\endgroup$ – Thane Brimhall Jun 25 '15 at 14:09

11 Answers 11

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Roll it home A large stone cube can't easily be rolled home because of the huge energy requirements to lift the center of mass high enough to roll over to the next face. So don't lift it.

Tie logs in a flattened pyramid pattern to the each of the sides of the cube perpendicular to the plane that Moses wants to roll the cube. This is aided by the fact that the cube is floating below the surface of the pool so Moses has access to all sides. When you're done, look at the cube normal to the desired plane of rotation. The cube sits in the middle surrounded by the logs and appears roughly cylindrical.

Water from the artifact would be largely beneficial in a number of ways for the trip home. First, damp sand gives way less than dry sand (think walking on wet sand close to the water compared to walking on dry sand higher up the beach). Second, the natural fiber ropes will expand and should tighten. However, it might be possible that the fibers chosen degrade rapidly under damp conditions than when dry. (Choice of rope fibers may be a way for the author to inject greater difficulty in getting the artifact home.) Third, anyone helping Moses get the artifact home has a constant supply of fresh water to drink thus easing logistics. Fourth, should the artifact need to be dragged instead of rolled, water acts as a lubricant.

On the downside, the logs may become waterlogged and get heavier and harder to get rolling.

This approach means you don't have to break up a priceless artifact, it has built in shipping protection and it's robust enough to roll over uneven, unprepared ground including sand. It's a plausible explanation for how the Egyptians moved blocks for the pyramids. Rollin' rollin' rollin'!

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  • $\begingroup$ This is quite clever! I wouldn't have thought of that. $\endgroup$ – Thane Brimhall Jun 24 '15 at 14:25
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    $\begingroup$ And it's better than a sphere because you know which way it will roll. If you're pushing it up a hill and want to take a break, just turn it sideways and it won't roll at all. $\endgroup$ – Green Jun 24 '15 at 14:27
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    $\begingroup$ I can visualize the concept, but you've got some fancy words in there. If you could include a picture / diagram I bet you'll get more up-votes. This is a great idea! $\endgroup$ – BrettFromLA Jun 24 '15 at 19:51
  • $\begingroup$ @BrettFromLA, done! $\endgroup$ – Green Jun 25 '15 at 1:40
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    $\begingroup$ Any chance you could go in depth about how you expect the properties of the artifact affect this design? Would being perpetually soaked be a benefit or a difficulty? $\endgroup$ – Thane Brimhall Jun 26 '15 at 0:40
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The awesome solution would be to dig a shallow channel and then tie the rock it to the bottom of a flat raft. Let the water-producing rock produce its own waterway so it can be floated home. Meanwhile the path behind becomes a trail of flowers as the desert soaks up the water left behind.

However it sounds as though the rock isn't producing quite enough water for that, so your ideal solution is probably on your classic cart or sledge. You have the advantage that the animals you use to pull it ( and if you're smart those will be mules because they work well in hot conditions ) will have a ready supply of water available, so progress may be slow but it should be viable travel. Whether you use a sledge, a cart, or some kind or maybe a crossover vehicle where you can change between the two, will depend whether it is your conventional relatively flat and rocky desert or a sahara-like ocean of sand. In either case you would need to keep moving because the rock would be perpetually making it's own mud, though collecting that water for your stock and crew - maybe with an overflow that pipes excess water way out behind your equipment- would be the smart thing to do.

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    $\begingroup$ I like this idea because it uses the special properties of the artifact as part of the solution. $\endgroup$ – Thane Brimhall Jun 24 '15 at 15:44
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    $\begingroup$ I like that "awesome solution" too (with the raft). Thought of it myself. I was going to add it as an answer if someone else hadn't come up with it. $\endgroup$ – BrettFromLA Jun 24 '15 at 19:53
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Getting Out of The Water

There are some options:

  • Moses could make a ramp next to it, tie rope onto the block, and pull it out. Use a beast of burden if it's too heavy for Moses. (Even small teams of oxen can supposedly pull over 10,000 lbs over the correct surfaces!)

  • Moses could use a lever. This would require some strong wood, though, and wood is scare in the desert, so this isn't the most viable option. Additionally, the block may be too strong for your lever, which is a further barrier. Furthermore, the cave itself may be too small for a properly sized lever or have some geometry which does not allow a fulcrum.

  • If there is not enough room for beasts of burden or levers, simply dig up to the block from below. The idea here is to produce a ramp Moses can push the block down to get it on a cart or sleigh. Since Moses has access to not-quite modern technology, he could use black powder to quarry this ramp.

Over Rock Travel: Carts

I know this is not creative, but Moses may have no choice. Use a big wagon or handcart (with lots of strong friends). Stone has been transported this way historically. Simply buying a cart may be expensive, but a wise merchant could see the value in investing in such a venture.

Additionally, Moses ought to use an a-frame or other pulley system to raise it or remove it from the cart. He needs a mechanical advantage as to not hurt himself and move the block.

Over-Sand Travel: Sleighs

This is taking from the system that the Ancient, pyramid-building Egyptians supposedly used to transport blocks of stone for their pyramids. The techniques looks like this:

  1. Place Stone on sleigh
  2. Wet sand in front of sleigh (using water from the stone, of course) This reduces friction considerably, making pulling the sleigh much easier.
  3. Pull sleigh over wet sand until you reach dry sand.
  4. Repeat until arrival at the desired point.

See page 12 of this UCLA publication. The Washington Post talks about this, as well. Phys.org talks about it here. Here is an academic paper for the hardcore skeptics, from the University of Amsterdam.

There is some debate as to if sleighs were used, or if Egyptians simply wrapped the blocks with poles and rolled them. Such sleighs have been found, and the wear and holes on them are consistent with the above method. (People question the wrapped-around-the-block method on several fronts, including structural strength of wood and wood's availability.)

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  • $\begingroup$ A sleigh is a terrible idea. It works under the premise that the very little surface area touching the ground is touching ice, which is very slippery. The wheels of a cart too would dig into the sand, and wet sand would be worse still, making a cart impractical for most of the trip home. Your article for transporting large stones to build the pyramids would seem to suggest that wooden cradles were strapped to all four sides to make it more "round" and thus easier to push. $\endgroup$ – Neil Jun 24 '15 at 5:45
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    $\begingroup$ I believe the Egyptians building the pyramids used the sledge and wet sand option. It sounds totally crazy but actually seems to work. $\endgroup$ – Bookeater Jun 24 '15 at 8:25
  • $\begingroup$ Actually sleighs help on any reasonably level surface. This is because even if the ground is uneven and high friction, the runners will be smooth and slippery, especially if covered by thin layer off water from the stone. Model it as somebody moving the earth against the surface of the runners and you'll get the idea. This vastly reduces both friction and the changes you get stuck. $\endgroup$ – Ville Niemi Jun 24 '15 at 11:27
  • $\begingroup$ That said, unless you can prepare the ground like the Egyptians did, people usually used some lower weight solution of the same principle such as the travois. Without prepared ground it would be just as good, be easier to build, and adds less weight you have to drag. $\endgroup$ – Ville Niemi Jun 24 '15 at 11:30
  • $\begingroup$ @Neil The link is there if the OP thinks this is worth looking into. I've simply provided the link as a starting point for his/her research, and provided a very brief summary here. Experiments seem to point that this method actually works, despite your objections. $\endgroup$ – PipperChip Jun 24 '15 at 17:29
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Infinite anything out of nothing = Perpetual motion machine.

Since you have infinite water, you can use it and redirect it, almost like a hose. If you pressurize it enough, you may be able to use it to push yourself via water cannon, or to fire the blast into a "water sail".

To pressurize the water, you can use either a pump, or gravity. Just build a really really tall water tower that's attached to the vehicle.

Alternatively, you could just rig it up to some "waterwheel cars". (They look like this)

Front view:

                 [Magic rock]
                /  |      |  \    <--- "\" is a hose that redirects the water 
               |=| |      | |=|
               |=|_|______|_|=|   <--- waterwheels
               |=| ^        |=|
                   |__ Those are the supports that hold up the rock relative to the wheels, and the axle of the car.

Side view: 


                 [Magic rock]   ---> Moves this way 
                  \          \    <---- "hose" sections point to front of wheels
               ===          ===
             == o ==      == o ==   <---- wheels 
               ===          ===

Note that because there's so much water, the ground may be slippery and going up slopes might be a problem. In that case, you can get out an push. Don't forget to put spikes on the wheels to help it get more grip in the mushy ground. You can also use a prop on the back that drags along, so that when it goes uphill and starts to roll backwards, the prop sticks into the ground and stops it.

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  • $\begingroup$ Love the ASCII-art blueprints! This was my gut instinct on how to move the artifact. $\endgroup$ – Thane Brimhall Jun 26 '15 at 18:18
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    $\begingroup$ I specialize in ASCII-art blueprints ;) $\endgroup$ – Aify Jun 26 '15 at 18:19
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How about spreading sand in front of it? The ancient Egyptians used to move giant statues and blocks across the desert by making a sled and sliding it across the sand. They spread water out on the sand, which supposedly halved the force needed to tow the block or statue. With enough sand, the same technique could be used for your block, except the water would just come from the block. Then the block could be towed by some horses or something.

enter image description here

As far as getting the block out, you could use a treadwheel to lift the block from the water. Treadwheels are kind of like a hampster excersize wheel. A human walks inside them, and uses the power from their walking to lift the block. A large treadwheel can give a mechanical advantage of 14:1, which is well over enough to lift the block, especially with a couple people!

enter image description here

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  • $\begingroup$ I like the treadwheel idea. It's pretty unique. $\endgroup$ – Thane Brimhall Jun 26 '15 at 17:21
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I'm assuming this pool has an outlet of some kind - otherwise it would overflow, unless the stone had some sort of pressure-valve feedback mechanism.

I would start by levering up the block with a crowbar, and slipping a couple of narrow logs underneath the block to raise it off the bottom of the pool. (They'd have to be narrow, or their buoyancy would make it impossible to drag them to the bottom of the pool.) Then I'd keep lashing logs to the existing logs to make a raft, until the whole assembly starts to float.

Then I'd dam up the pool's outlet with something, and wait for the cave system to fill up with water, so I could float the block out top of its own underground lake. (I note in passing that humanity has thousands of years' experience with caves filling up with water that suggest that this might be kind of dangerous, but whatever).

After that, if you just manage to keep it afloat, it's just a matter of time until it reaches the nearest sea. From time to time it might end up in a valley that would otherwise be difficult to extract it from, but again, all you have to do is wait. Eventually the valley fills with water, and you keep going. Just keep minding the raft.

More fancifully, it's also worth noting that this thing is effectively a perpetual motion machine. Seal it in a tank, let the overflow run a waterwheel, and gear that waterwheel to the axles of a cart. No need to feed those pesky mules.

Since I'm supposing that the original pool has an outlet that can take the output of a small spring, that kind of implies that the cave the pool is in has pretty good drainage, like maybe it's a cave in a mountain. In that case, you could dam the stream wherever it exits the mountain, wait for the cave system fill up, then kick out the dam and let a mighty river to carry the raft downstream. This seems, if possible, even more dangerous - not just to Moses, but to whoever is unfortunate enough to live downstream.

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  • $\begingroup$ Excellent answer. I've been waiting for a "perpetual motion" answer, which seemed obvious to me, but clearly not to everyone else. $\endgroup$ – Thane Brimhall Jun 26 '15 at 17:06
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Rope and food! (and some wood)

In the stone age people dragged stones by rope across a floor made of roundwood. If you have enough people you can dispense with the roundwood. If the sand drags too much you can build a sledge for the stone. To cross holes or uneven cave floors use levers.

For example on Easter Island much larger and heavier stones were transported for miles. I've done it myself in a small experiment of historical re-enactment. It is easy!

So all our Mozes really needs is lots of rope and food. People will flock to the job when the existence of this miracle stone becomes known.

In case of any surplus budget two giant wheels can be created around the stone to make life more easy. And shave off a year or so travelling time. But these are not essential.

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Move the city to the cave. It is easier.

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    $\begingroup$ C'mon, it would take him 40 years just to show people the way. $\endgroup$ – user8808 Jun 24 '15 at 9:37
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Moses could create a valve and tie it to the artifact to increase pressure.

First he would have to point the artifact slightly upward (a friend from town and lever good enough would do), maybe use some pulleys and rope attached do nearby palm tree. Add some support so it wont fall down when water drops. He could dig up a retention pool next to the original, and join them long enough for the top of the artefact to emerge. Then close the connection. Then stream of high pressure water would fill retention pool instead of original, meaning that original would dry soon.

In the meantime he should prepare round logs and put them under the artifact, in parallel to it. Dig flat enough slope in the bank. Then slowly remove support and lower it to the logs, do not release the rope yet. Pull slowly on the rope and move logs from behind of the artifact to front. This should work in most places, as artifact is not so large and such procession should fit on most roads. Wetting the sand in front will prevent it from digging in the sand, instead of rolling.

O and if every piece produces water, he could leave a crumble in the lake after he gets out of it. That way he could even make TWO lakes joining the retention one again :D

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The most important element is that water is not compressible. If the stone has one flat side and "secretes" water at the pace indicated you would have difficulty stopping the thing from sliding about on a perfectly flat non-water permeable surface like a sheet of metal. It's like the perfect lubricant. All you need are a couple of metal plates fitted with pulleys and you ramp it out.

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Here is one possible solution that would be really awesome, however it requires a way to turn up the volume of water the artifact outputs. Say that after being stumped by this for about a day, Moses finds some kind of a user interface to allow him to increase the amount of water the artifact outputs. This could be a dial or a magical HUD activated by a hand gesture or something. This artifact would be mostly useless to the city without a way to increase its output anyway.

Next he could get a fairly large barrel and somehow maneuver the artifact into the barrel. After this he would tie a bunch of ropes around the opening to prevent the artifact from falling out. Finally he could turn up the water full blast. This could propel the artifact like a rocket. It would be very difficult to control until he manages to lash it onto a cart, but after that he would have smooth sailing. He wouldn't even need a horse. It would be better if he could rig up a steering wheel, but even if he doesn't, he can stop, turn, and start again all the way back to the city. Of course he can't actually stop the water, but he can turn it back down.

This will require a lot of trial and error, but he will eventually get it there, and he doesn't need to break his back.

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