Add mods: technic, moreores, paintings, Nyancat (Pbj_pup). Small fix: sandwiches

mods/technic_plus_beta/technic/doc/substances.md

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+
+substances
+----------
+
+### ore ###
+
+The technic mod makes extensive use of not just the default ores but also
+some that are added by mods.  You will need to mine for all the ore types
+in the course of the game.  Each ore type is found at a specific range of
+elevations, and while the ranges mostly overlap, some have non-overlapping
+ranges, so you will ultimately need to mine at more than one elevation
+to find all the ores.  Also, because one of the best elevations to mine
+at is very deep, you will be unable to mine there early in the game.
+
+Elevation is measured in meters, relative to a reference plane that
+is not quite sea level.  (The standard sea level is at an elevation
+of about +1.4.)  Positive elevations are above the reference plane and
+negative elevations below.  Because elevations are always described this
+way round, greater numbers when higher, we avoid the word "depth".
+
+The ores that matter in technic are coal, iron, copper, tin, zinc,
+chromium, uranium, silver, gold, mithril, mese, and diamond.
+
+Coal is part of the basic Minetest game.  It is found from elevation
++64 downwards, so is available right on the surface at the start of
+the game, but it is far less abundant above elevation 0 than below.
+It is initially used as a fuel, driving important machines in the early
+part of the game.  It becomes less important as a fuel once most of your
+machines are electrically powered, but burning fuel remains a way to
+generate electrical power.  Coal is also used, usually in dust form, as
+an ingredient in alloying recipes, wherever elemental carbon is required.
+
+Iron is part of the basic Minetest game.  It is found from elevation
++2 downwards, and its abundance increases in stages as one descends,
+reaching its maximum from elevation -64 downwards.  It is a common metal,
+used frequently as a structural component.  In technic, unlike the basic
+game, iron is used in multiple forms, mainly alloys based on iron and
+including carbon (coal).
+
+Copper is part of the basic Minetest game (having migrated there from
+moreores).  It is found from elevation -16 downwards, but is more abundant
+from elevation -64 downwards.  It is a common metal, used either on its
+own for its electrical conductivity, or as the base component of alloys.
+Although common, it is very heavily used, and most of the time it will
+be the material that most limits your activity.
+
+Tin is part of the basic Minetest game (having migrated there from
+moreores).  It is found from elevation +8 downwards, with no
+elevation-dependent variations in abundance beyond that point.
+It is a common metal.  Its main use in pure form is as a component
+of electrical batteries.  Apart from that its main purpose is
+as the secondary ingredient in bronze (the base being copper), but bronze
+is itself little used.  Its abundance is well in excess of its usage,
+so you will usually have a surplus of it.
+
+Zinc is supplied by technic.  It is found from elevation +2 downwards,
+with no elevation-dependent variations in abundance beyond that point.
+It is a common metal.  Its main use is as the secondary ingredient
+in brass (the base being copper), but brass is itself little used.
+Its abundance is well in excess of its usage, so you will usually have
+a surplus of it.
+
+Chromium is supplied by technic.  It is found from elevation -100
+downwards, with no elevation-dependent variations in abundance beyond
+that point.  It is a moderately common metal.  Its main use is as the
+secondary ingredient in stainless steel (the base being iron).
+
+Uranium is supplied by technic.  It is found only from elevation -80 down
+to -300; using it therefore requires one to mine above elevation -300 even
+though deeper mining is otherwise more productive.  It is a moderately
+common metal, useful only for reasons related to radioactivity: it forms
+the fuel for nuclear reactors, and is also one of the best radiation
+shielding materials available.  It is not difficult to find enough uranium
+ore to satisfy these uses.  Beware that the ore is slightly radioactive:
+it will slightly harm you if you stand as close as possible to it.
+It is safe when more than a meter away or when mined.
+
+Silver is supplied by the moreores mod.  It is found from elevation -2
+downwards, with no elevation-dependent variations in abundance beyond
+that point.  It is a semi-precious metal.  It is little used, being most
+notably used in electrical items due to its conductivity, being the best
+conductor of all the pure elements.
+
+Gold is part of the basic Minetest game (having migrated there from
+moreores).  It is found from elevation -64 downwards, but is more
+abundant from elevation -256 downwards.  It is a precious metal.  It is
+little used, being most notably used in electrical items due to its
+combination of good conductivity (third best of all the pure elements)
+and corrosion resistance.
+
+Mithril is supplied by the moreores mod.  It is found from elevation
+-512 downwards, the deepest ceiling of any minable substance, with
+no elevation-dependent variations in abundance beyond that point.
+It is a rare precious metal, and unlike all the other metals described
+here it is entirely fictional, being derived from J. R. R. Tolkien's
+Middle-Earth setting.  It is little used.
+
+Mese is part of the basic Minetest game.  It is found from elevation
+-64 downwards.  The ore is more abundant from elevation -256 downwards,
+and from elevation -1024 downwards there are also occasional blocks of
+solid mese (each yielding as much mese as nine blocks of ore).  It is a
+precious gemstone, and unlike diamond it is entirely fictional.  It is
+used in many recipes, though mainly not in large quantities, wherever
+some magical quality needs to be imparted.
+
+Diamond is part of the basic Minetest game (having migrated there from
+technic).  It is found from elevation -128 downwards, but is more abundant
+from elevation -256 downwards.  It is a precious gemstone.  It is used
+moderately, mainly for reasons connected to its extreme hardness.
+
+### rock ###
+
+In addition to the ores, there are multiple kinds of rock that need to be
+mined in their own right, rather than for minerals.  The rock types that
+matter in technic are standard stone, desert stone, marble, and granite.
+
+Standard stone is part of the basic Minetest game.  It is extremely
+common.  As in the basic game, when dug it yields cobblestone, which can
+be cooked to turn it back into standard stone.  Cobblestone is used in
+recipes only for some relatively primitive machines.  Standard stone is
+used in a couple of machine recipes.  These rock types gain additional
+significance with technic because the grinder can be used to turn them
+into dirt and sand.  This, especially when combined with an automated
+cobblestone generator, can be an easier way to acquire sand than
+collecting it where it occurs naturally.
+
+Desert stone is part of the basic Minetest game.  It is found specifically
+in desert biomes, and only from elevation +2 upwards.  Although it is
+easily accessible, therefore, its quantity is ultimately quite limited.
+It is used in a few recipes.
+
+Marble is supplied by technic.  It is found in dense clusters from
+elevation -50 downwards.  It has mainly decorative use, but also appears
+in one machine recipe.
+
+Granite is supplied by technic.  It is found in dense clusters from
+elevation -150 downwards.  It is much harder to dig than standard stone,
+so impedes mining when it is encountered.  It has mainly decorative use,
+but also appears in a couple of machine recipes.
+
+### rubber ###
+
+Rubber is a biologically-derived material that has industrial uses due
+to its electrical resistivity and its impermeability.  In technic, it
+is used in a few recipes, and it must be acquired by tapping rubber trees.
+
+If you have the moretrees mod installed, the rubber trees you need
+are those defined by that mod.  If not, technic supplies a copy of the
+moretrees rubber tree.
+
+Extracting rubber requires a specific tool, a tree tap.  Using the tree
+tap (by left-clicking) on a rubber tree trunk block extracts a lump of
+raw latex from the trunk.  Each trunk block can be repeatedly tapped for
+latex, at intervals of several minutes; its appearance changes to show
+whether it is currently ripe for tapping.  Each tree has several trunk
+blocks, so several latex lumps can be extracted from a tree in one visit.
+
+Raw latex isn't used directly.  It must be vulcanized to produce finished
+rubber.  This can be performed by alloying the latex with coal dust.
+
+### metal ###
+
+Many of the substances important in technic are metals, and there is
+a common pattern in how metals are handled.  Generally, each metal can
+exist in five forms: ore, lump, dust, ingot, and block.  With a couple of
+tricky exceptions in mods outside technic, metals are only *used* in dust,
+ingot, and block forms.  Metals can be readily converted between these
+three forms, but can't be converted from them back to ore or lump forms.
+
+As in the basic Minetest game, a "lump" of metal is acquired directly by
+digging ore, and will then be processed into some other form for use.
+A lump is thus more akin to ore than to refined metal.  (In real life,
+metal ore rarely yields lumps ("nuggets") of pure metal directly.
+More often the desired metal is chemically bound into the rock as an
+oxide or some other compound, and the ore must be chemically processed
+to yield pure metal.)
+
+Not all metals occur directly as ore.  Generally, elemental metals (those
+consisting of a single chemical element) occur as ore, and alloys (those
+consisting of a mixture of multiple elements) do not.  In fact, if the
+fictional mithril is taken to be elemental, this pattern is currently
+followed perfectly.  (It is not clear in the Middle-Earth setting whether
+mithril is elemental or an alloy.)  This might change in the future:
+in real life some alloys do occur as ore, and some elemental metals
+rarely occur naturally outside such alloys.  Metals that do not occur
+as ore also lack the "lump" form.
+
+The basic Minetest game offers a single way to refine metals: cook a lump
+in a furnace to produce an ingot.  With technic this refinement method
+still exists, but is rarely used outside the early part of the game,
+because technic offers a more efficient method once some machines have
+been built.  The grinder, available only in electrically-powered forms,
+can grind a metal lump into two piles of metal dust.  Each dust pile
+can then be cooked into an ingot, yielding two ingots from one lump.
+This doubling of material value means that you should only cook a lump
+directly when you have no choice, mainly early in the game when you
+haven't yet built a grinder.
+
+An ingot can also be ground back to (one pile of) dust.  Thus it is always
+possible to convert metal between ingot and dust forms, at the expense
+of some energy consumption.  Nine ingots of a metal can be crafted into
+a block, which can be used for building.  The block can also be crafted
+back to nine ingots.  Thus it is possible to freely convert metal between
+ingot and block forms, which is convenient to store the metal compactly.
+Every metal has dust, ingot, and block forms.
+
+Alloying recipes in which a metal is the base ingredient, to produce a
+metal alloy, always come in two forms, using the metal either as dust
+or as an ingot.  If the secondary ingredient is also a metal, it must
+be supplied in the same form as the base ingredient.  The output alloy
+is also returned in the same form.  For example, brass can be produced
+by alloying two copper ingots with one zinc ingot to make three brass
+ingots, or by alloying two piles of copper dust with one pile of zinc
+dust to make three piles of brass dust.  The two ways of alloying produce
+equivalent results.
+
+### iron and its alloys ###
+
+Iron forms several important alloys.  In real-life history, iron was the
+second metal to be used as the base component of deliberately-constructed
+alloys (the first was copper), and it was the first metal whose working
+required processes of any metallurgical sophistication.  The game
+mechanics around iron broadly imitate the historical progression of
+processes around it, rather than the less-varied modern processes.
+
+The two-component alloying system of iron with carbon is of huge
+importance, both in the game and in real life.  The basic Minetest game
+doesn't distinguish between these pure iron and these alloys at all,
+but technic introduces a distinction based on the carbon content, and
+renames some items of the basic game accordingly.
+
+The iron/carbon spectrum is represented in the game by three metal
+substances: wrought iron, carbon steel, and cast iron.  Wrought iron
+has low carbon content (less than 0.25%), resists shattering, and
+is easily welded, but is relatively soft and susceptible to rusting.
+In real-life history it was used for rails, gates, chains, wire, pipes,
+fasteners, and other purposes.  Cast iron has high carbon content
+(2.1% to 4%), is especially hard, and resists corrosion, but is
+relatively brittle, and difficult to work.  Historically it was used
+to build large structures such as bridges, and for cannons, cookware,
+and engine cylinders.  Carbon steel has medium carbon content (0.25%
+to 2.1%), and intermediate properties: moderately hard and also tough,
+somewhat resistant to corrosion.  In real life it is now used for most
+of the purposes previously satisfied by wrought iron and many of those
+of cast iron, but has historically been especially important for its
+use in swords, armor, skyscrapers, large bridges, and machines.
+
+In real-life history, the first form of iron to be refined was
+wrought iron, which is nearly pure iron, having low carbon content.
+It was produced from ore by a low-temperature furnace process (the
+"bloomery") in which the ore/iron remains solid and impurities (slag)
+are progressively removed by hammering ("working", hence "wrought").
+This began in the middle East, around 1800 BCE.
+
+Historically, the next forms of iron to be refined were those of high
+carbon content.  This was the result of the development of a more
+sophisticated kind of furnace, the blast furnace, capable of reaching
+higher temperatures.  The real advantage of the blast furnace is that it
+melts the metal, allowing it to be cast straight into a shape supplied by
+a mould, rather than having to be gradually beaten into the desired shape.
+A side effect of the blast furnace is that carbon from the furnace's fuel
+is unavoidably incorporated into the metal.  Normally iron is processed
+twice through the blast furnace: once producing "pig iron", which has
+very high carbon content and lots of impurities but lower melting point,
+casting it into rough ingots, then remelting the pig iron and casting it
+into the final moulds.  The result is called "cast iron".  Pig iron was
+first produced in China around 1200 BCE, and cast iron later in the 5th
+century BCE.  Incidentally, the Chinese did not have the bloomery process,
+so this was their first iron refining process, and, unlike the rest of
+the world, their first wrought iron was made from pig iron rather than
+directly from ore.
+
+Carbon steel, with intermediate carbon content, was developed much later,
+in Europe in the 17th century CE.  It required a more sophisticated
+process, because the blast furnace made it extremely difficult to achieve
+a controlled carbon content.  Tweaks of the blast furnace would sometimes
+produce an intermediate carbon content by luck, but the first processes to
+reliably produce steel were based on removing almost all the carbon from
+pig iron and then explicitly mixing a controlled amount of carbon back in.
+
+In the game, the bloomery process is represented by ordinary cooking
+or grinding of an iron lump.  The lump represents unprocessed ore,
+and is identified only as "iron", not specifically as wrought iron.
+This standard refining process produces dust or an ingot which is
+specifically identified as wrought iron.  Thus the standard refining
+process produces the (nearly) pure metal.
+
+Cast iron is trickier.  You might expect from the real-life notes above
+that cooking an iron lump (representing ore) would produce pig iron that
+can then be cooked again to produce cast iron.  This is kind of the case,
+but not exactly, because as already noted cooking an iron lump produces
+wrought iron.  The game doesn't distinguish between low-temperature
+and high-temperature cooking processes: the same furnace is used not
+just to cast all kinds of metal but also to cook food.  So there is no
+distinction between cooking processes to produce distinct wrought iron
+and pig iron.  But repeated cooking *is* available as a game mechanic,
+and is indeed used to produce cast iron: re-cooking a wrought iron ingot
+produces a cast iron ingot.  So pig iron isn't represented in the game as
+a distinct item; instead wrought iron stands in for pig iron in addition
+to its realistic uses as wrought iron.
+
+Carbon steel is produced by a more regular in-game process: alloying
+wrought iron with coal dust (which is essentially carbon).  This bears
+a fair resemblance to the historical development of carbon steel.
+This alloying recipe is relatively time-consuming for the amount of
+material processed, when compared against other alloying recipes, and
+carbon steel is heavily used, so it is wise to alloy it in advance,
+when you're not waiting for it.
+
+There are additional recipes that permit all three of these types of iron
+to be converted into each other.  Alloying carbon steel again with coal
+dust produces cast iron, with its higher carbon content.  Cooking carbon
+steel or cast iron produces wrought iron, in an abbreviated form of the
+bloomery process.
+
+There's one more iron alloy in the game: stainless steel.  It is managed
+in a completely regular manner, created by alloying carbon steel with
+chromium.
+
+### uranium enrichment ###
+
+When uranium is to be used to fuel a nuclear reactor, it is not
+sufficient to merely isolate and refine uranium metal.  It is necessary
+to control its isotopic composition, because the different isotopes
+behave differently in nuclear processes.
+
+The main isotopes of interest are U-235 and U-238.  U-235 is good at
+sustaining a nuclear chain reaction, because when a U-235 nucleus is
+bombarded with a neutron it will usually fission (split) into fragments.
+It is therefore described as "fissile".  U-238, on the other hand,
+is not fissile: if bombarded with a neutron it will usually capture it,
+becoming U-239, which is very unstable and quickly decays into semi-stable
+(and fissile) plutonium-239.
+
+Inconveniently, the fissile U-235 makes up only about 0.7% of natural
+uranium, almost all of the other 99.3% being U-238.  Natural uranium
+therefore doesn't make a great nuclear fuel.  (In real life there are
+a small number of reactor types that can use it, but technic doesn't
+have such a reactor.)  Better nuclear fuel needs to contain a higher
+proportion of U-235.
+
+Achieving a higher U-235 content isn't as simple as separating the U-235
+from the U-238 and just using the required amount of U-235.  Because
+U-235 and U-238 are both uranium, and therefore chemically identical,
+they cannot be chemically separated, in the way that different elements
+are separated from each other when refining metal.  They do differ
+in atomic mass, so they can be separated by centrifuging, but because
+their atomic masses are very close, centrifuging doesn't separate them
+very well.  They cannot be separated completely, but it is possible to
+produce uranium that has the isotopes mixed in different proportions.
+Uranium with a significantly larger fissile U-235 fraction than natural
+uranium is called "enriched", and that with a significantly lower fissile
+fraction is called "depleted".
+
+A single pass through a centrifuge produces two output streams, one with
+a fractionally higher fissile proportion than the input, and one with a
+fractionally lower fissile proportion.  To alter the fissile proportion
+by a significant amount, these output streams must be centrifuged again,
+repeatedly.  The usual arrangement is a "cascade", a linear arrangement
+of many centrifuges.  Each centrifuge takes as input uranium with some
+specific fissile proportion, and passes its two output streams to the
+two adjacent centrifuges.  Natural uranium is input somewhere in the
+middle of the cascade, and the two ends of the cascade produce properly
+enriched and depleted uranium.
+
+Fuel for technic's nuclear reactor consists of enriched uranium of which
+3.5% is fissile.  (This is a typical value for a real-life light water
+reactor, a common type for power generation.)  To enrich uranium in the
+game, it must first be in dust form: the centrifuge will not operate
+on ingots.  (In real life uranium enrichment is done with the uranium
+in the form of a gas.)  It is best to grind uranium lumps directly to
+dust, rather than cook them to ingots first, because this yields twice
+as much metal dust.  When uranium is in refined form (dust, ingot, or
+block), the name of the inventory item indicates its fissile proportion.
+Uranium of any available fissile proportion can be put through all the
+usual processes for metal.
+
+A single centrifuge operation takes two uranium dust piles, and produces
+as output one dust pile with a fissile proportion 0.1% higher and one with
+a fissile proportion 0.1% lower.  Uranium can be enriched up to the 3.5%
+required for nuclear fuel, and depleted down to 0.0%.  Thus a cascade
+covering the full range of fissile fractions requires 34 cascade stages.
+(In real life, enriching to 3.5% uses thousands of cascade stages.
+Also, centrifuging is less effective when the input isotope ratio
+is more skewed, so the steps in fissile proportion are smaller for
+relatively depleted uranium.  Zero fissile content is only asymptotically
+approachable, and natural uranium relatively cheap, so uranium is normally
+only depleted to around 0.3%.  On the other hand, much higher enrichment
+than 3.5% isn't much more difficult than enriching that far.)
+
+Although centrifuges can be used manually, it is not feasible to perform
+uranium enrichment by hand.  It is a practical necessity to set up
+an automated cascade, using pneumatic tubes to transfer uranium dust
+piles between centrifuges.  Because both outputs from a centrifuge are
+ejected into the same tube, sorting tubes are needed to send the outputs
+in different directions along the cascade.  It is possible to send items
+into the centrifuges through the same tubes that take the outputs, so the
+simplest version of the cascade structure has a line of 34 centrifuges
+linked by a line of 34 sorting tube segments.
+
+Assuming that the cascade depletes uranium all the way to 0.0%,
+producing one unit of 3.5%-fissile uranium requires the input of five
+units of 0.7%-fissile (natural) uranium, takes 490 centrifuge operations,
+and produces four units of 0.0%-fissile (fully depleted) uranium as a
+byproduct.  It is possible to reduce the number of required centrifuge
+operations by using more natural uranium input and outputting only
+partially depleted uranium, but (unlike in real life) this isn't usually
+an economical approach.  The 490 operations are not spread equally over
+the cascade stages: the busiest stage is the one taking 0.7%-fissile
+uranium, which performs 28 of the 490 operations.  The least busy is the
+one taking 3.4%-fissile uranium, which performs 1 of the 490 operations.
+
+A centrifuge cascade will consume quite a lot of energy.  It is
+worth putting a battery upgrade in each centrifuge.  (Only one can be
+accommodated, because a control logic unit upgrade is also required for
+tube operation.)  An MV centrifuge, the only type presently available,
+draws 7 kEU/s in this state, and takes 5 s for each uranium centrifuging
+operation.  It thus takes 35 kEU per operation, and the cascade requires
+17.15 MEU to produce each unit of enriched uranium.  It takes five units
+of enriched uranium to make each fuel rod, and six rods to fuel a reactor,
+so the enrichment cascade requires 514.5 MEU to process a full set of
+reactor fuel.  This is about 0.85% of the 6.048 GEU that the reactor
+will generate from that fuel.
+
+If there is enough power available, and enough natural uranium input,
+to keep the cascade running continuously, and exactly one centrifuge
+at each stage, then the overall speed of the cascade is determined by
+the busiest stage, the 0.7% stage.  It can perform its 28 operations
+towards the enrichment of a single uranium unit in 140 s, so that is
+the overall cycle time of the cascade.  It thus takes 70 min to enrich
+a full set of reactor fuel.  While the cascade is running at this full
+speed, its average power consumption is 122.5 kEU/s.  The instantaneous
+power consumption varies from second to second over the 140 s cycle,
+and the maximum possible instantaneous power consumption (with all 34
+centrifuges active simultaneously) is 238 kEU/s.  It is recommended to
+have some battery boxes to smooth out these variations.
+
+If the power supplied to the centrifuge cascade averages less than
+122.5 kEU/s, then the cascade can't run continuously.  (Also, if the
+power supply is intermittent, such as solar, then continuous operation
+requires more battery boxes to smooth out the supply variations, even if
+the average power is high enough.)  Because it's automated and doesn't
+require continuous player attention, having the cascade run at less
+than full speed shouldn't be a major problem.  The enrichment work will
+consume the same energy overall regardless of how quickly it's performed,
+and the speed will vary in direct proportion to the average power supply
+(minus any supply lost because battery boxes filled completely).
+
+If there is insufficient power to run both the centrifuge cascade at
+full speed and whatever other machines require power, all machines on
+the same power network as the centrifuge will be forced to run at the
+same fractional speed.  This can be inconvenient, especially if use
+of the other machines is less automated than the centrifuge cascade.
+It can be avoided by putting the centrifuge cascade on a separate power
+network from other machines, and limiting the proportion of the generated
+power that goes to it.
+
+If there is sufficient power and it is desired to enrich uranium faster
+than a single cascade can, the process can be speeded up more economically
+than by building an entire second cascade.  Because the stages of the
+cascade do different proportions of the work, it is possible to add a
+second and subsequent centrifuges to only the busiest stages, and have
+the less busy stages still keep up with only a single centrifuge each.
+
+Another possible approach to uranium enrichment is to have no fixed
+assignment of fissile proportions to centrifuges, dynamically putting
+whatever uranium is available into whichever centrifuges are available.
+Theoretically all of the centrifuges can be kept almost totally busy all
+the time, making more efficient use of capital resources, and the number
+of centrifuges used can be as little (down to one) or as large as desired.
+The difficult part is that it is not sufficient to put each uranium dust
+pile individually into whatever centrifuge is available: they must be
+input in matched pairs.  Any odd dust pile in a centrifuge will not be
+processed and will prevent that centrifuge from accepting any other input.
+
+### concrete ###
+
+Concrete is a synthetic building material.  The technic modpack implements
+it in the game.
+
+Two forms of concrete are available as building blocks: ordinary
+"concrete" and more advanced "blast-resistant concrete".  Despite its
+name, the latter has no special resistance to explosions or to any other
+means of destruction.
+
+Concrete can also be used to make fences.  They act just like wooden
+fences, but aren't flammable.  Confusingly, the item that corresponds
+to a wooden "fence" is called "concrete post".  Posts placed adjacently
+will implicitly create fence between them.  Fencing also appears between
+a post and adjacent concrete block.