A phenomenon similar electricity can be used in OE-Cake. Electrical Conduction (also known as Jaussaud-Baker conduction) can be used to precisely control ignition in a Powder-based engine, create traps that activate quickly over distance, to make a hotplate with an on/off switch, to create lights that blink in a pattern, and probably many, many other things.
Activating Electrical Conduction
Conduction is enabled by setting fuelLightProbability to 1 and fuelExtinguishProbability to 0 in the Parameters of the save that you wish to enable conduction in. This causes materials containing Fuel to instantly burst into flame all over when touched by Hot, and never burn out. Mixing Fuel and Water into a material causes the material to try to put itself out. This results in a material that turns Hot all over when in contact with a Hot material, and then near-instantly stops being Hot when the Hot object is removed.
Any material containing Fuel and Water will be conductive. A good material to start with is FQW, conductive Wall. Interesting fact: because the conductive material contains Water, and we electrify it with Hot, the typical conductive material "evaporates" from FQ into FQGL. If for some reason being light and floaty is a problem, it can be mitigated by adding Cold.
Conduction was likely not intentionally programmed into the game, and as such takes some extra effort to work well. Sadly, conductive Elastic/String is impossible due to melting. As such it is actually rather difficult to made a flexible conductor. Creating inflexible conductive wire out Rigid/Wall is rather easy: the Pencil tool is adept at drawing wire that will conduct Hot from source to destination. However, mating the ends of the wire to a device or two wires to each other is occasionally challenging. The most common problem is being too far away: Blob mode makes it all too easy to notice your wire isn't actually touching. Wire drawn at standardDistance=0.75 (the default) conducts well enough but is still rather strange sometimes. Drawing wire with the Pencil tool at standardDistance=0.9 is much more reliable.
Creating conductive surfaces that are structural is the greatest challenge. If the entire structure must be conductive, standardDistance=0.5 works well enough. Sometimes the best way to make an electrical shape is to make the durable shape out of normal unconductive material and then cover the surface in conductive wire. Any conductive object drawn with the Shape tool or the Brush tool at any standardDistance exhibits a very complex interference pattern, caused by each individual particle being in contact with more than one other particle. The Water and Fuel+Hot fight each other, causing certain parts of a conductive surface (ie. a "metal" pot, or anything drawn without the Pencil tool) to be "dead" and certain parts to be "live". This pattern changes constantly and in real-time, leading to a fluctuating, wavey, lightning-like pattern that can easily be seen in a large block of conductive material in Material view mode.
I'm putting this here because this is the most relevant page. Similar to conduction, there is a reaction that uses Hot and Cold to "detect" a certain level of pressure. Using default settings, the material HQW instantly self-evaporates to HQWGL and changes to a paler color. When exposed to Cold it will temporarily "condense" back into HQW and return to it's darker color, instantly evaporating when Cold is removed. The Hot does not conduct around the entire shape, but instead stays at the site of contact. For some reason the Cold does not instantly condense the Water, it needs to be pressed on with some force in order for the particles to get close enough to activate. This reaction provides a visual response to a certain amount of contact pressure.
Enabling the conductive material disables the use of normal Burning, collapsing Fuel. However one can reprogram Powder to closely represent it, by setting powderExplosionCoefficient=0. Any material with this type of Powder added to it (for example, PR) will catch fire like normal, but will eventually crumble just like Fuel due to powderExtinguishProbability. Of course, this disables use of percussive Powder, so you have to pick your chemistry carefully. Adding the Fuel element will re-add the fire animation if you desire, without worrying about forever-burning fuel. If you really, really need conduction, burning fuel, and explosives, the normal Mochibomb remains useful.
While theoretically possible, I have not yet successfully replaced Powder. I believe it is possible to use the Viscous reaction to create something similar to Powder's explosion. Under certain circumstances, Viscous can cause an explosion of high-speed particles.
Anisotropy"Anisotropic" means that something is different depending on what angle it is presented with. Your phone or computer screen or TV has an anisotropic screen - it looks fine straight on, but the colors get wonky when you look at it from an angle. Electrical conduction in OE-Cake has some anisotropic attributes. For an unknown reason, "electricity" in OE-Cake strongly prefers to travel from right to left and from top to bottom. Conduction generally works any time, any where, but occasionally it just won't do what you need it to because of these rules. Designing conductive shapes on a moving object could have unexpected electrical properties.
One last thing: after a conductive material has been used once, it collects a "static charge" caused by usually one or two leftover Hot quanta conducting back and forth along the otherwise dead conductor. These are troublesome when dealing with sensitive targets such as explosives, and must be removed by contact with non-conductive Water. An easy way to set this up for certain projects is to have the "off" position of the switch made of Rigid+Water to damp any undesired conduction.
For some reason, this lightning-like conduction flows from right to left, as well as conduction in general. Occasionally problems will be had trying to conduct directly up/down or to the far right side of a dense conductor, but these problems can usually be fixed with better design. Another very strange phenomena in conductive blocks is teleportation. When a Hot particle conducting from right to left reaches the left side of the object, it will teleport to the right side of the block and start again. This is more likely to occur in a denser conductive block.
A complete circuit is unnecessary, but conduction seems to have "direction", away from the source with a slight bias towards the nearest "output". Trying to light two hotplates strung in a parallel circuit, most power will short-circuit to the nearest hotplate where it is lost to evaporation. Two hotplates in series is near useless. Anyone who learns how to effectively branch a wire will likely unlock great power, since almost always the flow of Hot will follow the wire that is marginally closer to the intersection even if it means abandoning the original wire. Perfectly created intersections may be the secret to creating logic devices because the flow of Hot seems to prefer the easiest/shortest path, thus the choice of path is correlated with the electrical potential of each path, which could be affected by a previous output or it's own current load. A source of power leading to an intersection but with each path connected to the other creating a loop would produce a very strange pattern of conduction.
Not that it matters because I don't think anybody is likely to read this far, but the strange behaviour visible in blocks of conductive material has several modes. Blocks drawn above standardDistance=1 are not conductive due to particles not touching each other. Blocks drawn at standardDistance=1 exhibit a strange Conway's Game of Life-esque appearance. Blocks drawn below standardDistance=1 are conductive and generate a strange conductive orbiting/looping pattern where Hot conducts from right to left then jumps back to the right side to run again. Blocks drawn below standardDistance=1 but above standardDistance=0.7071067812 are the most stable and have sensible conduction, due to each particle only touching those directly above/below and left/right. Below standardDistance=0.7071067812 each particle also has contact with it's diagonal neighbors, further complicating the interference pattern from hot fuel/water. Blocks drawn at standardDistance=0.7071067812 display a conductive crawl pattern, where instead of conducting and looping/teleporting horizontally, the conduction loop will wander slowly up and down the block. Blocks drawn below standardDistance=0.7071067812 but above standardDistance=0.5 produce chaotic wandering, where instead of wandering gracefully each Hot loop jumps up and down. It's location could be expressed as a probability because the loop does not hop far, you can see it still wandering up and down to an extent but it no longer forms a distinct line. Blocks drawn at or below standardDistance=0.5 follow different rules, because not only does each individual particle touch it's North/South and East/West and diagonal neighbors, but also touches the second neighbor to the North/South and East/West. Hot is conducted chaotically and any one particle's location would best be described in a probability cloud. Below a certain distance it takes waaay too much power to actually have enough power at a high enough gain to do anything. Approaching standardDistance=0, the entire block (if you dump enough juice into it) becomes a superconductor which will occasionally transmit some power to any section of it, but it gets very hard to build a junction to add or extract power.