[HN Gopher] The tyranny of the wagon equation
       ___________________________________________________________________
        
       The tyranny of the wagon equation
        
       Author : dTal
       Score  : 191 points
       Date   : 2022-09-06 11:37 UTC (11 hours ago)
        
 (HTM) web link (maximumeffort.substack.com)
 (TXT) w3m dump (maximumeffort.substack.com)
        
       | Sniffnoy wrote:
       | This is known in mathematics as the Jeep problem:
       | https://en.wikipedia.org/wiki/Jeep_problem
        
         | superjan wrote:
         | In university, my colleague students were developing strategies
         | to the "camel banana problem" for transporting n bananas by
         | camel into the desert.
         | 
         | https://puzzling.stackexchange.com/questions/230/a-camel-tra...
        
       | JAA1337 wrote:
        
       | zardo wrote:
       | To make this map to the real world, terrain must be taken into
       | account. Obviously donkeys can haul more weight over more
       | distance on flat ground than climbing a mountain pass.
       | 
       | What's the approach to doing that? Make the delta and v terms
       | functions of the terrain? Re-derive the equation based on energy
       | rather than distance?
        
         | smallnamespace wrote:
         | Even easier: redefine distance, e.g. 1 mountain mile = 5 flat
         | ground miles
        
       | dragontamer wrote:
       | There is an escape from the donkey in practice.
       | 
       | Its called a boat, which can scale as big as possible and supply
       | any number of donkeys across the entirety of the Mediterranean.
        
         | thunderbird120 wrote:
         | In practicality there was also another solution in the ancient
         | world. If you're going conquering you're probably going
         | somewhere with people to conquer. Those people probably have
         | food. Just take theirs.
        
           | throwawayffffas wrote:
           | It's called foraging, it's what practically everyone did.
           | It's a nasty business and you can't do it to the same people
           | twice, because it typically involved killing and enslaving
           | that people.
           | 
           | https://acoup.blog/2022/07/29/collections-logistics-how-
           | did-...
        
           | toss1 wrote:
           | >> "Just take theirs"
           | 
           | That "Just" word is carrying a very heavy load . . .
           | 
           | (The people whose food you are planning to forage will be
           | objecting, likely with weapons)
        
             | yetanother4968 wrote:
             | More likely they are fleeing since they are largely unarmed
             | peasants, who can't stand up to trained, armed, and armored
             | soldiers.
        
               | 988747 wrote:
               | And when they flee they take some of their food supplies
               | with them and hide the rest. Foraging army might be able
               | to find some of it, but rarely all. Also, if you are in
               | enemy territory it is entirely possible to completely
               | miss some remote village. It's not like they have a
               | satellite map.
        
               | toss1 wrote:
               | >>And when they flee they take some of their food
               | supplies with them and hide the rest
               | 
               | YUP!
               | 
               | And beyond that, what they can't take or hide, they may
               | very well burn to slow down the advance
               | 
               | Just because you have advance spies and they report
               | existing supplies, you just cannot count on having those
               | available when the full infantry arrives.
        
           | bombcar wrote:
           | The underlying blog post goes into details on that, too. It
           | is covered in "foraging"
           | https://acoup.blog/2022/08/12/collections-logistics-how-
           | did-...
        
         | mellavora wrote:
         | as long as you are near the shore-line, I can see that working.
         | Though you might also need to be near a port;
         | loading/offloading is less efficient without infrastructure.
         | 
         | However, there may be other uses for the port, which suggests
         | most of the good ports will have cities built around them.
         | 
         | So yes, as long as you constrain your march to the area around
         | friendly cities, boats work great
        
           | tomjen3 wrote:
           | You don't really need much infrastructure when you don't use
           | containers for your boats.
        
           | dragontamer wrote:
           | > as long as you are near the shore-line
           | 
           | Look at Bronze / early Iron age Mediterranean empires. They
           | stuck to the shorelines.
           | 
           | https://en.wikipedia.org/wiki/Ancient_Carthage#/media/File:C.
           | ..
           | 
           | https://upload.wikimedia.org/wikipedia/commons/f/f7/Greek_Co.
           | ..
        
             | marcosdumay wrote:
             | They started moving inroad after they started making roads.
        
         | bee_rider wrote:
         | The blog posts by Devereaux (acoup blog) that spurred this on,
         | are specifically about over-land logistics. Boats, of course,
         | avoid this problem entirely -- assuming all of your targets are
         | coastal or by rivers!
        
       | Animats wrote:
       | Caravans faced this problem, but the solution was commercial -
       | the caravanserai.
       | 
       | A serai is a corral for animals. A caravanserai is a truck stop -
       | fuel, food, motel, parking. Caravans resupplied at caravanserai.
       | The Silk Road was a chain of caravanserai. If there's enough
       | local production to supply a caravanserai, caravans can take that
       | route.
       | 
       | The military version of this is a chain of supply bases. This is
       | all too common. A gallon of diesel fuel delivered by the US
       | military to outermost bases in Afghanistan could cost well over
       | US$100. Part of the trip was made by transport aircraft, and part
       | by helicopter, all of it consuming fuel. Bases have to be within
       | helicopter range of each other. The main justification for the
       | Osprey, which is a horrible kludge of an aircraft, is more range,
       | allowing fewer bases to reach a goal.
        
         | JJMcJ wrote:
         | By no means an expert but my understanding is that if you can't
         | make the logistics work for a military operation then the
         | chances of failure are very high, maybe even literally 100%.
        
           | chasd00 wrote:
           | my 10 year old, out of the blue, told me once "artillery wins
           | battles but logistics wins wars". Heh he's really into a
           | couple youtube history channels.
        
           | trhway wrote:
           | Watch the Kherson region now - Russia has a 25K strong army
           | on the right side of Dneper river there, and thanks to US
           | supplied high precision rockets Ukraine has practically
           | disabled the bridges leading there, so that Russian army has
           | only minimal supply using ferries. The railway from Crimea to
           | those bridges and ferries had also been constantly stricken
           | (frequently the strike would be at a large military supply
           | train riding there)
        
         | schoen wrote:
         | > If there's enough local production to supply a caravanserai,
         | caravans can take that route.
         | 
         | That's an interesting constraint; were there also extra-
         | expensive caravanserai in places where that production wasn't
         | quite local and some of those resources had to be trucked, er,
         | caravanned in?
        
           | samatman wrote:
           | Sort of, mostly yes, but never fodder or water. This is the
           | great advantage of the camel: if a camel train rolls into a
           | caravanserai, and the available fodder at that oasis has been
           | eaten, there's a good change they'll make it to the next
           | oasis with thin, very unhappy, camels. Mules would just die.
        
         | csours wrote:
         | I had heard of caravanserai from the idle/progression Kittens
         | Game. I wish I had looked it up earlier.
        
       | vitiral wrote:
       | Funny.
       | 
       | However, I find some assumptions suspect. Unlike rockets, donkeys
       | can consume fuel en-route by grazing. Armies can also consume
       | fuel by hunting, plundering and being "quartered" by their own
       | people. You can make "supply trains" by having small groups of
       | military gather such resources from a closer distance.
       | 
       | This is probably fairly accurate for camels and distances in the
       | Saharan desert though, and you'd have to add the weight of water
       | as well!
        
         | qikInNdOutReply wrote:
         | What about the vorbis strategy of placing supplies in hidden
         | caches ahead of time without a return trip along the route?
         | 
         | Imagine that applied to the rocket equation. Stationary fuel
         | tanks attaching to the rocket mid rise..
        
           | gibspaulding wrote:
           | Stationary fuel tanks seem problematic for rockets since your
           | rendezvous would have to happen at such high speeds. You'd
           | either have to decelerate the rocket back to zero or
           | accelerate the fuel to the speed of the rocket.
        
             | Robotbeat wrote:
             | There are some places that your relative velocity with a
             | propellant depot may be near zero already.
             | 
             | Natural staging points are not stationary, but they may be
             | in fixed orbits, such as LEO (of a certain altitude,
             | inclination), maybe a halo orbit of a Lagrange point
             | (NASA's Gateway is in NHRO, which is similar), or a highly
             | Elliptical orbit near escape velocity. And you can do this
             | for Mars as well.
             | 
             | By refilling at these staging points, you can chop up the
             | rocket equation so you don't get hit hard by the
             | exponential. You have to get fuel there in the first place,
             | and to do that you can use slower, more efficient
             | trajectories or solar-electric propulsion (much higher Isp
             | but slower) or in situ propellant production. You can also
             | have better cooling at these staging points, taking a mass
             | penalty off your crewed vehicle and offloaded to the depot
             | in the case of cryogenic propellants that may boil off over
             | time without an active chiller.
             | 
             | Propellant depots are a pretty powerful tool for expanding
             | capability for space exploration. NASA picked SpaceX's
             | Starship as the lander for their Artemis lunar missions,
             | and that will fuel up using a depot in Earth orbit.
        
             | philwelch wrote:
             | Remember that all motion is relative. You can't model space
             | travel as simply going from point to point. Instead, you
             | transfer from orbit to orbit and have to match velocities
             | wherever you go. Relative to the propellant depot you have
             | to reach zero velocity, but the propellant depot will be
             | orbiting something at a very high speed just like you are.
             | 
             | You will likely have to go out of your way somewhat to
             | reach a propellant depot, so you don't want your propellant
             | depots at the bottom of heavy gravity wells or in hard-to-
             | reach orbits. But it's still a viable strategy.
        
           | JAA1337 wrote:
        
           | throwawayffffas wrote:
           | Well that was a strategy indeed but it can only go so far,
           | additionally the same logistics apply to the food you place
           | in the cache, you have to transport it there, the meat of the
           | original article was, that really you are constrained in your
           | movement by the terrains agricultural output, in high
           | production terrain, your population and the enemies
           | population as well will stockpile food for themselves that
           | the army can draw upon, in places where the terrain is not
           | suitable for high intensity agriculture the food available is
           | much less and an army would quickly find itself exhausting
           | all the stockpiles, in a matter of weeks, armies eat a lot of
           | food.
        
         | throwawayffffas wrote:
         | The original blog goes into a lot more detail, including the
         | mechanics, logistics and risks of foraging.
         | 
         | The solution to getting around the wagon equation is ships,
         | ships could carry tremendous amounts of food, with a minimal
         | crew and thus minimum consumption, only problem is ships are
         | expensive.
         | 
         | On donkeys, typically armies used mules and draft horses
         | instead of donkeys, because of behavioral and maximum load
         | reasons, and grazing is not enough for mules and large horses,
         | also on certain seasons there is not enough grass for animals
         | to graze in the terrain either.
         | 
         | The original blog has also a piece on nomad logistics, who used
         | significantly smaller horses that can be sustained only by
         | grazing, these armies were able to traverse a lot larger
         | distances, hence the success of the mongol armies.
        
           | antonymy wrote:
           | >only problem is ships are expensive.
           | 
           | Well not the only problem, there's also the fact ships are
           | limited to water deep enough to carry them, so you can't go
           | too far from the coast or navigable rivers. Granted, in
           | Europe, there are lots of navigable rivers that make
           | waterborne logistics fairly simple if you have the boats. Ask
           | the Vikings.
        
             | samatman wrote:
             | This is mitigated by the fact that rivers are attractive
             | places to live, so the odds that a target of conquest is on
             | a navigable river are fairly high.
             | 
             | Gets pretty bleak if this isn't true, and if your foe
             | doesn't have to stay put, much worse. The Chinese tried to
             | scour the horse barbarians of the hinterlands a few times.
             | Didn't go well.
        
             | dmckeon wrote:
             | In the 1200s the eastern horse-hordes used frozen rivers to
             | speed up their rate of advance and took much of the area
             | west of the Urals by surprise.
        
         | igorkraw wrote:
         | The linked source blog goes into that:
         | 
         | - grazing costs time, which increases the total amount of food
         | that must be carried
         | 
         | - foraging equally costs time, so foraging more means a slower
         | moving army
         | 
         | - but an army can only forage as it passes through terrain, so
         | you _need_ to keep moving, otherwise your army will eat the
         | area into starvation, then die
        
           | Retric wrote:
           | It's not quite that simple. Horses can eat much faster than
           | they can digest so a few short breaks can represent a lot of
           | food over a day. Further, horses eat significantly more than
           | people. A 30% slower pace that requires 40% less food per day
           | is a net win on distance but not time.
        
             | throwawayffffas wrote:
             | The main issue, is that the horses of agricultural
             | societies are bred to a large size, and cannot survive by
             | grazing alone, they need to have grains in their diet.
        
               | Retric wrote:
               | That's false. Horses doing heavy work can't survive on
               | grazing alone, but they are perfectly fine when left
               | alone in good pasture. Thus the phrase "put out to
               | pasture," old animals where often given something of a
               | retirement where they where left to take care of
               | themselves rather than simply be killed.
        
               | [deleted]
        
               | geysersam wrote:
               | But the horses here will be doing work. Carrying men and
               | supplies. Or is that not heavy enough? Admittedly I know
               | very little about horses.
        
               | Retric wrote:
               | I don't know that much about horses but it's something
               | like:
               | 
               | A normal horse left to graze in good pasture can get a
               | calorie surplus per hour. That same horse doing work has
               | a calorie deficit per hour based on how strenuous the
               | labor. A horse can get into a maximum calorie debt before
               | issues happen. Thus a few day of hard labor plowing a
               | field isn't an issue by its self and having redundant
               | horses is useful.
               | 
               | In terms of the Wagon equation, taking a nearly empty
               | wagon back is vastly less strenuous than taking a full
               | one out. It may be that taking several times as long to
               | get back significantly extends the total distance you can
               | move the army from your base. It may also be that running
               | a calorie deficit on the outbound trip and then grazing
               | for days before the return trip is useful. But I doubt
               | any army is would actually try and approach any kind of
               | theoretical maximum as in practice flexibility is needed.
               | 
               | Granted that's for the average horse, where extreme
               | athletic performance means significant extra muscle mass
               | and thus higher caloric needs independent of actual work
               | being done. But the extreme athletic horses are expensive
               | to maintain so likely used by messengers etc not wagons
               | or farmers.
        
               | MichaelZuo wrote:
               | There may be a small net advantage to grazing and
               | foraging enroute but it certainly wouldn't double the
               | available tonnage transported.
        
               | watwut wrote:
               | Foraging require enough of density of settlements en
               | route. Cause that is what foraging is, taking food from
               | locals by force. The bigger the army, the more and bigger
               | settlements you need to burn and steal from.
        
         | thenthenthen wrote:
         | Im missing another option here, 'edible supply lines'; the
         | donkeys can be eaten. Only meant as last resort ;)
        
           | hinkley wrote:
           | Humans are more resilient than we give them credit for.
           | Compared to other mammals we have a lot of coping mechanisms
           | for injuries that are missing from other species.
           | 
           | There's a comedian who does a bit about how humans might be
           | the bad guy in horror movies made by aliens, because we can
           | scar in situations that would kill other animals, and we can
           | run in intervals for far longer than most other mammals. We
           | used them down, and that's probably part of our collaboration
           | with dogs. We're all basically Michael Myers. We just keep
           | coming, and as soon as you stop to rest, bam, there we are
           | again.
           | 
           | Point is, hoofed animals tend to get injured in ways that
           | will ultimately kill them. At that point if you have a
           | butcher handy, you can be both humane and efficient, without
           | necessarily being in a starvation situation. We talk about
           | agriculture being a pivot point in human development but
           | nobody ever seems to talk much about the power of soup.
        
             | gruez wrote:
             | >because we can scar in situations that would kill other
             | animals
             | 
             | examples? Humans aren't exactly resilient or fast healers
             | in my mind.
        
               | mcguire wrote:
               | I don't know what the OP has in mind, but if you break an
               | ankle, you can splint it and hobble until it heals. If a
               | large animal breaks an ankle, it's not going to heal.
        
               | nordsieck wrote:
               | > examples? Humans aren't exactly resilient or fast
               | healers in my mind.
               | 
               | Presumably they were referring to horses (and possibly
               | donkeys?) having to be euthanized after a broken leg.
               | Which is so well known, even "the Far Side" got in on the
               | action[1].
               | 
               | ---
               | 
               | 1. https://pbs.twimg.com/media/DKrF52OXUAUtJy3?format=jpg
               | &name=...
        
           | NeoTar wrote:
           | I believe this was the 'official' strategy of some early
           | arctic / antarctic expeditions. Kill the sledge dogs and feed
           | them to the other dogs plus humans.
        
             | cardiffspaceman wrote:
             | That's also part of a sound, but not vegan, anti-scurvy
             | strategy. Someone should do the first vegan trans-Antarctic
             | trek. But I digress.
        
       | ticviking wrote:
       | In an acquaintances DnD game he often enforces encumbrance and
       | logistics rules like this. Leading the players to realize, "this
       | plan requires infinite donkeys doesn't it?"
        
       | ballenf wrote:
       | One commenter questions whether generals and armies were capable
       | of the advanced math implicated by the harmonic transfer method.
       | 
       | But they don't have to do any advanced math. They just take food
       | for the fleet from a single donkey and turn that donkey around as
       | soon as his food supply equals the food necessary for the return
       | trip. Rinse and repeat. Right?
       | 
       | The reality does get a bit more complicated because at least one
       | guide is required for each donkey, so you really don't want to
       | lose a man for every donkey that turns back, and instead do the
       | maneuver in groups. You also need to feed the return guide.
       | 
       | Optimizing under those conditions gets a lot more complicated I
       | think.
       | 
       | You could also use this logic for sherpa-assisted mountain
       | climbing.
        
         | dylan604 wrote:
         | >because at least one guide is required for each donkey,
         | 
         | Why? Can you not assemble them in groups like other pack
         | animals?
        
           | bombcar wrote:
           | If you're sending them back one by one you need a guide for
           | each.
           | 
           | If you send them in groups then you're not as optimal (first
           | donkey is unladen in 3 days singly, but two donkeys are
           | unladen in 5 days, say, meaning you need to keep feeding the
           | first until the second is done, or equivalent via load
           | balancing).
           | 
           | You could have trained donkeys that might self-navigate but
           | that's moderately unlikely. Probably better to eat them or
           | give them away free to the countryside.
        
             | dylan604 wrote:
             | Sure, if you're unloading from the donkey serially. But if
             | you unloaded in parallel, no one donkey would be unloaded
             | before the others.
        
               | bombcar wrote:
               | That still delays when you can send the first donkey back
               | - and it continues to eat.
               | 
               | If you unload from one and send back immediately, it eats
               | 3 days, goes back.
               | 
               | If you unload in parallel, you cannot be sending a donkey
               | back in 3 days, so you must be feeding extra donkey.
               | 
               | It still may get you an advantage overall, but it's not
               | the maximum advantage.
        
               | scrumbledober wrote:
               | very analogous to airplanes running on fuel vs batteries
        
               | tialaramex wrote:
               | I was actually thinking it was like the Falklands.
               | 
               | https://en.wikipedia.org/wiki/Operation_Black_Buck
               | 
               | The British were able to fly bombers from tremendously
               | far away, with a chain re-fuel strategy where the re-
               | fuelling tanker planes are themselves re-fuelled by other
               | tankers which then turn back. Later iterations were
               | optimised by thinking more carefully about who should
               | transfer fuel, to who, and when, as in this example.
               | 
               | Arguably Black Buck was pointless, it was certainly not
               | pivotal in the outcome of the war, but the actual process
               | was fascinating.
        
         | jerf wrote:
         | This analysis also quite reasonably assumes zero transfer time
         | between donkeys, perfect knowledge to run donkeys to exactly
         | their limit (which are identical between all donkeys), and zero
         | overhead in general. That's all fine, it's an upper limit
         | analysis. But the overhead will be biting you in the
         | exponential regime, unfortunately.
         | 
         | Another thing to remember about "the old days" is that they may
         | not have computers and they may not have the Internet, but they
         | have LOTS of time to think about more efficiency compared to an
         | Internet commenter for whom this is merely a momentary side
         | diversion for a few moments, and a lot more motivation. I feel
         | satisfied with some of the answers to things like "How was
         | Stonehenge built?" that have been found in the last couple of
         | decades (or, if you prefer, "Can you show at least one method
         | that could have been used to build Stonehenge?"), but I think
         | one of the other lessons that was learned (at least by me) is
         | that "take a modern person, give them one try in their busy
         | lives to try the first thing that comes to their mind, and
         | declare the task impossible when that doesn't work" isn't a
         | very good way to understand the ancient world. They had _time_.
         | 
         | Would an ancient have described the "harmonic transfer
         | technique" in this way? Heck no. Could they have worked their
         | way to it through trial, error, and much simpler thinking?
         | Absolutely. Finding that solution doesn't require calculus.
         | Calculus just supplies a very nice analysis framework and a
         | fantastic communication tool between the post author and us
         | readers.
        
       | cwmma wrote:
       | The diagram of the Quadruple donkey transfer reminds me of the
       | fueling diagram for the Black Buck raids during the Falklands War
       | 
       | 1.
       | https://en.wikipedia.org/wiki/Operation_Black_Buck#/media/Fi...
        
         | sparkplug94 wrote:
         | That's actually shockingly similar. I'm sure someone has
         | studied the mathematics of fuel transport in much greater
         | detail -- I wonder if it's a simple problem to optimize or
         | something closer to the traveling salesman problem
        
           | cwmma wrote:
           | pretty sure it's a very simple problem, brutally simple even.
        
       | deepnotderp wrote:
       | A better analogy would be the Breguet range equation, as the
       | rocket equation is explicitly about delta-V, not distance.
       | 
       | https://aerospaceengineeringblog.com/breguet-range-equation/
        
       | mabbo wrote:
       | The author misses a key important point: you can also _eat the
       | donkey_.
        
         | 988747 wrote:
         | But you can't feed the donkey to remaining donkeys.
        
           | progre wrote:
           | I'v seen donkeys happily munching down plastic bags and
           | cardboard. I sure you could feed dried donkey meat to a
           | donkey (not saying it's a good idea)
        
             | 988747 wrote:
             | And the effect for a donkey would be probably similar to
             | eating plastic bags: They cannot properly digest it so they
             | suffer from malnutrition, eventually die.
        
         | zardo wrote:
         | That would certainly extend your range, but it would be very
         | costly in donkeys. Instead of needing 1000 donkeys to sustain a
         | siege, you now need say 100 donkeys/day.
        
       | andrewf wrote:
       | Reminds me of that time the RAF _really_ wanted to drop some
       | bombs on the Falkland Islands rather than leaving it to the Navy
       | and its Sea Harriers.
       | 
       | Diagram:
       | https://en.wikipedia.org/wiki/File:Refuelling.plan.black.buc...
       | Full article: https://en.wikipedia.org/wiki/Operation_Black_Buck
        
       | photochemsyn wrote:
       | A text-based 'Oregon Trail'-style game could be built out of this
       | concept, where the player starts with a fixed sum of money and
       | has to buy enough donkeys and food, plus perhaps plan a route
       | with optimal water and grazing potential, to reach their
       | destination.
        
       | h2odragon wrote:
       | > Thus, the harmonic donkey transfer, using four donkeys, yields
       | a maximum transport distance 1/12 * L0 longer than the pairwise
       | donkey transfer.
       | 
       | Upvote earned there.
        
         | sparkplug94 wrote:
         | Haha thank you! I'm the original author of the linked article,
         | and I had a LOT of fun naming the donkey transfer algorithms I
         | came up with.
        
         | moron4hire wrote:
         | Without digging into any math myself, I find it curious that
         | it's 1/12th longer. That specific ratio, 1/12th, is also the
         | basis for the Equal Temperament system for tuning Western
         | musical instruments ("12-tone Equal Temperament, specifically),
         | which _also_ represents a harmonic series.
         | 
         | https://en.wikipedia.org/wiki/Equal_temperament
        
           | oakwhiz wrote:
           | 1+2+3+...=-1/12 by certain definitions...
        
       | csense wrote:
       | Once your nation gets big enough, you can't supply frontier
       | armies from the capital. You need to draw food from local
       | sources. In territory you control, the peasants pay some of their
       | food to the local fortress in taxes, and the fortress acts as a
       | supply base for any army that needs to go through.
       | 
       | Once you get past border action and deep into enemy territory,
       | the tyranny of the wagon equation means it's down to "forage" --
       | hunt / fish / gather resources from the wild, or steal food from
       | the local population at swordpoint.
       | 
       | One option is to pause your campaign until you can consolidate
       | your gains and build or take over supply bases in captured
       | territory.
       | 
       | Another option is to change your tactics to recognize the limits
       | of what a foraging army can achieve. E.g. avoiding sieges and
       | terrorizing civilians / burning towns to try to force a
       | surrender, or using a cavalry army or fast-moving elite infantry
       | to launch a surprise attack in an unexpected location.
        
       | crest wrote:
       | This assumes that beasts of burden aren't edible...
        
         | bombcar wrote:
         | The underlying blog post (which is MUCH more detailed) goes
         | into that (not sure which of the three went into it in detail)
         | https://acoup.blog/2022/07/15/collections-logistics-how-did-...
         | 
         | There are problems with eating the beasts, but in certain cases
         | it _can_ extend your range, but not as much as you might think.
        
           | endominus wrote:
           | There's also an element of "burning the ships" in that idea;
           | you extend your current operational range at the cost of the
           | logistical capacity (in terms of carried food) of the future.
           | In other words, if you eat all your horses and you're still
           | behind enemy lines, your army is now in serious trouble of
           | not being able plunder enough food to make it anywhere before
           | starving and deserting.
        
             | BizarroLand wrote:
             | To add to that, we can, with our current technology, for a
             | handful of billion dollars send a rocket to Andromeda that
             | would arrive in 10,000 to 65,000 years.
             | 
             | But if we want the rocket to be anything more than a pitted
             | lump of metal when it arrives, say, sending information
             | back, operating scanners, etc, the price jumps
             | exponentially (assuming any useful technology we build
             | could still be usable even after 100 years in deep space).
             | 
             | It ultimately boils down not to the "Can we do it", but "Is
             | it WISE to do it", and that is always either the more
             | difficult or more expensive question to answer.
        
               | credit_guy wrote:
               | > send a rocket to Andromeda that would arrive in 10,000
               | to 65,000 years
               | 
               | Andromeda is 2.5 million light years away. You are
               | probably thinking of sending some vehicle to the closest
               | star, Proxima Centauri, which is just about 4.25 light
               | years away. This is the same as 270000 AU away; Voyager 1
               | has been launched 45 years ago, and it's at 157 AU from
               | Earth, which means it traveled at an average speed of
               | about 3.5 AU/year. At this speed it would take it 77000
               | years to get to Proxima Centauri.
        
               | BizarroLand wrote:
               | Dang it, right, yes. Thank you for the correction.
        
             | credit_guy wrote:
             | Well, Xenophon and 10000 other Greeks found themselves deep
             | into enemy territory, without supplies [1]. Somehow they
             | managed to survive. They took some food by force, but
             | mostly they used diplomacy and negotiation. Diplomacy is
             | fairly effective when you have lots of weapons.
             | 
             | [1] https://en.wikipedia.org/wiki/Anabasis_(Xenophon)
        
               | salawat wrote:
               | Once more proving that violence is the original
               | diplomatic currency.
        
       | shalmanese wrote:
       | > "Hierarchy, Vorbis said later. The Ephebians didn't think in
       | terms of hierarchies.
       | 
       | > No army could cross the desert. But maybe a small army could
       | get a quarter of the way, and leave a cache of water. And do that
       | several times. And another small army could use part of that
       | cache to go further, maybe reach halfway, and leave a cache. And
       | another small army . . .
       | 
       | > It had taken months. A third of the men had died, of heat and
       | dehydration and wild animals and worse things, the worse things
       | that the desert held . . .
       | 
       | > You had to have a mind like Vorbis's to plan it.
       | 
       | > And plan it early. Men were already dying in the desert before
       | Brother Murduck went to preach; there was already a beaten track
       | when the Omnian fleet burned in the bay before Ephebe.
       | 
       | > You had to have a mind like Vorbis's to plan your retaliation
       | before your attack."
       | 
       | - Small Gods, Terry Pratchett
        
         | schoen wrote:
         | I thought "that's a funny coincidence with the Vorbis file
         | format name!" ... but then I thought maybe it wasn't a
         | coincidence at all. And it wasn't!
         | 
         | https://en.wikipedia.org/wiki/Vorbis#Name
        
       | chmod600 wrote:
       | I read that Ghengis Khan did much better by making good use of
       | grazing lands and timing the seasons.
        
         | brazzy wrote:
         | Yes - but that meant his entire army had to be cavalry, and
         | could basically only operate on steppe-like land.
        
       | nvader wrote:
       | Bring war material with you from home, but forage on the enemy.
       | Thus the army will have food enough for its needs.
       | 
       | --Sun Tzu, The Art of War
        
         | mcguire wrote:
         | It works well enough to be a consistent strategy, but you have
         | to be careful taking too much from a given piece of territory.
         | Eventually, the locals start getting unhappy with you.
         | 
         | And then there's things like the Thirty Years' War, where
         | armies foraged their way through territories often enough that
         | eventually there was nothing left.
        
           | zardo wrote:
           | > Eventually, the locals start getting unhappy with you.
           | 
           | Pretty sure the locals are unhappy from the start of the
           | foraging process, with all the stealing, murdering, and
           | raping.
        
             | pessimizer wrote:
             | Unhappy is being used here to mean "unhappy enough that it
             | affects you." It's not about concern for the mental health
             | of the locals.
        
           | watwut wrote:
           | I think that with Thirty Years' War, it was not just
           | "foraging"bur also religious cleansing. It was kind of
           | genocide. They did not had word genocide yet, but generally
           | it fits.
        
       | [deleted]
        
       | docandrew wrote:
       | "Harmonic Donkey Transfer" would be a good band name or album
       | title.
        
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       (page generated 2022-09-06 23:00 UTC)