From fb93388f06fe87ee75aaaf04cf6edcf01a26d981 Mon Sep 17 00:00:00 2001 From: SmallJoker <mk939@ymail.com> Date: Thu, 19 Jul 2018 14:36:21 +0200 Subject: [PATCH] Replace deprecated invsize[] with size[] --- manual.md | 165 +++++++++++++++++++++++++++++++++++++++++++++++++----- 1 files changed, 149 insertions(+), 16 deletions(-) diff --git a/manual.md b/manual.md index 1b8f1ed..4ad01fc 100644 --- a/manual.md +++ b/manual.md @@ -179,10 +179,7 @@ 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 simply cooking the latex, with each -latex lump producing one lump of rubber. If you have an extractor, -however, the latex is better processed there: each latex lump will -produce three lumps of rubber. +rubber. This can be performed by alloying the latex with coal dust. ### metal ### @@ -672,6 +669,142 @@ in both locked and unlocked flavors. All of the chests work with the pneumatic tubes of the pipeworks mod. +radioactivity +------------- + +The technic mod adds radioactivity to the game, as a hazard that can +harm player characters. Certain substances in the game are radioactive, +and when placed as blocks in the game world will damage nearby players. +Conversely, some substances attenuate radiation, and so can be used +for shielding. The radioactivity system is based on reality, but is +not an attempt at serious simulation: like the rest of the game, it has +many simplifications and deliberate deviations from reality in the name +of game balance. + +In real life radiological hazards can be roughly divided into three +categories based on the time scale over which they act: prompt radiation +damage (such as radiation burns) that takes effect immediately; radiation +poisoning that becomes visible in hours and lasts weeks; and cumulative +effects such as increased cancer risk that operate over decades. +The game's version of radioactivity causes only prompt damage, not +any delayed effects. Damage comes in the abstracted form of removing +the player's hit points, and is immediately visible to the player. +As with all other kinds of damage in the game, the player can restore +the hit points by eating food items. High-nutrition foods, such as the +pie baskets supplied by the bushes\_classic mod, are a useful tool in +dealing with radiological hazards. + +Only a small range of items in the game are radioactive. From the technic +mod, the only radioactive items are uranium ore, refined uranium blocks, +nuclear reactor cores (when operating), and the materials released when +a nuclear reactor melts down. Other mods can plug into the technic +system to make their own block types radioactive. Radioactive items +are harmless when held in inventories. They only cause radiation damage +when placed as blocks in the game world. + +The rate at which damage is caused by a radioactive block depends on the +distance between the source and the player. Distance matters because the +damaging radiation is emitted equally in all directions by the source, +so with distance it spreads out, so less of it will strike a target +of any specific size. The amount of radiation absorbed by a target +thus varies in proportion to the inverse square of the distance from +the source. The game imitates this aspect of real-life radioactivity, +but with some simplifications. While in real life the inverse square law +is only really valid for sources and targets that are small relative to +the distance between them, in the game it is applied even when the source +and target are large and close together. Specifically, the distance is +measured from the center of the radioactive block to the abdomen of the +player character. For extremely close encounters, such as where the +player swims in a radioactive liquid, there is an enforced lower limit +on the effective distance. + +Different types of radioactive block emit different amounts of radiation. +The least radioactive of the radioactive block types is uranium ore, +which causes 0.25 HP/s damage to a player 1 m away. A block of refined +but unenriched uranium, as an example, is nine times as radioactive, +and so will cause 2.25 HP/s damage to a player 1 m away. By the inverse +square law, the damage caused by that uranium block reduces by a factor +of four at twice the distance, that is to 0.5625 HP/s at a distance of 2 +m, or by a factor of nine at three times the distance, that is to 0.25 +HP/s at a distance of 3 m. Other radioactive block types are far more +radioactive than these: the most radioactive of all, the result of a +nuclear reactor melting down, is 1024 times as radioactive as uranium ore. + +Uranium blocks are radioactive to varying degrees depending on their +isotopic composition. An isotope being fissile, and thus good as +reactor fuel, is essentially uncorrelated with it being radioactive. +The fissile U-235 is about six times as radioactive than the non-fissile +U-238 that makes up the bulk of natural uranium, so one might expect that +enriching from 0.7% fissile to 3.5% fissile (or depleting to 0.0%) would +only change the radioactivity of uranium by a few percent. But actually +the radioactivity of enriched uranium is dominated by the non-fissile +U-234, which makes up only about 50 parts per million of natural uranium +but is about 19000 times more radioactive than U-238. The radioactivity +of natural uranium comes just about half from U-238 and half from U-234, +and the uranium gets enriched in U-234 along with the U-235. This makes +3.5%-fissile uranium about three times as radioactive as natural uranium, +and 0.0%-fissile uranium about half as radioactive as natural uranium. + +Radiation is attenuated by the shielding effect of material along the +path between the radioactive block and the player. In general, only +blocks of homogeneous material contribute to the shielding effect: for +example, a block of solid metal has a shielding effect, but a machine +does not, even though the machine's ingredients include a metal case. +The shielding effect of each block type is based on the real-life +resistance of the material to ionising radiation, but for game balance +the effectiveness of shielding is scaled down from real life, more so +for stronger shield materials than for weaker ones. Also, whereas in +real life materials have different shielding effects against different +types of radiation, the game only has one type of damaging radiation, +and so only one set of shielding values. + +Almost any solid or liquid homogeneous material has some shielding value. +At the low end of the scale, 5 meters of wooden planks nearly halves +radiation, though in that case the planks probably contribute more +to safety by forcing the player to stay 5 m further away from the +source than by actual attenuation. Dirt halves radiation in 2.4 m, +and stone in 1.7 m. When a shield must be deliberately constructed, +the preferred materials are metals, the denser the better. Iron and +steel halve radiation in 1.1 m, copper in 1.0 m, and silver in 0.95 m. +Lead would halve in 0.69 m (its in-game shielding value is 80). Gold halves radiation +in 0.53 m (factor of 3.7 per meter), but is a bit scarce to use for +this purpose. Uranium halves radiation in 0.31 m (factor of 9.4 per +meter), but is itself radioactive. The very best shielding in the game +is nyancat material (nyancats and their rainbow blocks), which halves +radiation in 0.22 m (factor of 24 per meter), but is extremely scarce. See [technic/technic/radiation.lua](https://github.com/minetest-technic/technic/blob/master/technic/radiation.lua) for the in-game shielding values, which are different from real-life values. + +If the theoretical radiation damage from a particular source is +sufficiently small, due to distance and shielding, then no damage at all +will actually occur. This means that for any particular radiation source +and shielding arrangement there is a safe distance to which a player can +approach without harm. The safe distance is where the radiation damage +would theoretically be 0.25 HP/s. This damage threshold is applied +separately for each radiation source, so to be safe in a multi-source +situation it is only necessary to be safe from each source individually. + +The best way to use uranium as shielding is in a two-layer structure, +of uranium and some non-radioactive material. The uranium layer should +be nearer to the primary radiation source and the non-radioactive layer +nearer to the player. The uranium provides a great deal of shielding +against the primary source, and the other material shields against +the uranium layer. Due to the damage threshold mechanism, a meter of +dirt is sufficient to shield fully against a layer of fully-depleted +(0.0%-fissile) uranium. Obviously this is only worthwhile when the +primary radiation source is more radioactive than a uranium block. + +When constructing permanent radiation shielding, it is necessary to +pay attention to the geometry of the structure, and particularly to any +holes that have to be made in the shielding, for example to accommodate +power cables. Any hole that is aligned with the radiation source makes a +"shine path" through which a player may be irradiated when also aligned. +Shine paths can be avoided by using bent paths for cables, passing +through unaligned holes in multiple shield layers. If the desired +shielding effect depends on multiple layers, a hole in one layer still +produces a partial shine path, along which the shielding is reduced, +so the positioning of holes in each layer must still be considered. +Tricky shine paths can also be addressed by just keeping players out of +the dangerous area. + electrical power ---------------- @@ -828,7 +961,8 @@ energy to let an electrical network cope with mismatched supply and demand. They have a secondary purpose of charging and discharging powered tools. They are thus a mixture of electrical infrastructure, -powered machine, and generator. +powered machine, and generator. Battery boxes connect to cables only +from the bottom. MV and HV battery boxes have upgrade slots. Energy upgrades increase the capacity of a battery box, each by 10% of the un-upgraded capacity. @@ -843,10 +977,10 @@ infrastructure of that tier, just to get access to faster charging. MV and HV battery boxes work with pneumatic tubes. An item can be input -to the charging slot through the bottom of the battery box, or to the -discharging slot through the top. Items are not accepted through the -front, back, or sides. With a tube upgrade, fully charged/discharged -tools (as appropriate for their slot) will be ejected through a side. +to the charging slot through the sides or back of the battery box, or +to the discharging slot through the top. With a tube upgrade, fully +charged/discharged tools (as appropriate for their slot) will be ejected +through a side. ### processing machines ### @@ -1110,12 +1244,12 @@ ### hydro generator ### -The hydro generator is an LV power generator that generates a small amount -of power from the natural motion of water. To operate, the generator must -be horizontally adjacent to water. It doesn't matter whether the water -consists of source blocks or flowing blocks. Having water adjacent on -more than one side, up to the full four, increases the generator's output. -The water itself is unaffected by the generator. +The hydro generator is an LV power generator that generates a respectable +amount of power from the natural motion of water. To operate, the +generator must be horizontally adjacent to flowing water. The power +produced is dependent on how much flow there is across any or all four +sides, the most flow of course coming from water that's flowing straight +down. ### geothermal generator ### @@ -1349,6 +1483,5 @@ * sonic screwdriver * liquid cans * wrench -* radioactivity * frames * templates -- Gitblit v1.8.0