Voidstone exposed in a wall on Level 1 after explosives were detonated.
Object 50, otherwise known as voidstone, is an infinitely strong, perfectly black, and immovable material that is prevalent within the Backrooms. It is found buried within the walls, floors, and ceilings in a number of the levels and is what prevents the millions of square kilometers of rooms from caving in. It can also be used as an infinite source of energy and is known to provide power in most of the levels.
Description
Voidstone is indestructible. It never bends, cracks, degrades, or deforms and no matter how much force is applied to it, it does not move. This behavior is similar to how the prison bars in Level 3 or the tiles in Level 37 act.
All visible light that hits voidstone is absorbed. All surfaces of voidstone have the same perfect black color regardless of the viewing angle, making it impossible to discern corners or edges. Thus, samples of voidstone look two-dimensional.
Other forms of electromagnetic radiation, such as X-rays will also be absorbed; however, microwaves and radio waves are able to pass through. This allows Wi-Fi to permeate through walls.
Despite absorbing all light that hits it, it will never heat up. Voidstone is a thermal energy reservoir; a substance with a heat capacity so large that it never changes temperature no matter how much heat it absorbs or releases. A block of voidstone at 0 °C will stay at 0 °C even surrounded by fire. A block of voidstone at 100 °C will stay at 100 °C even if surrounded by ice.
In some locations, voidstone has been found at temperatures of hundreds of degrees. Hot enough that it glows red hot. Analyzing the light emitted through an optical spectrometer shows that voidstone glows with a perfect blackbody spectrum.
The surfaces of voidstone are frictionless. If not for air resistance, it would be possible to slide upon its surfaces indefinitely. This also makes it impossible to walk or stand on voidstone.
Voidstone is a perfect electric insulator, is hydrophobic, and does not allow air to pass through. It does not interact with gravity and will levitate stationarily if not supported by anything.
Prevalence
Voidstone is abundant and can be found in many levels, providing structural support to the levels’ rooms. It also serves as a barrier between the exterior of the levels and The Blue Channel. After digging a few meters through the surface-level materials, voidstone surfaces will be encountered. The surrounding concrete may also be reinforced with rebar made from voidstone. If this concrete is dug out, what gets left behind are floating voidstone rods.
It is unclear how voidstone rebar was able to embed itself into concrete given that it is unmovable. However, this rebar has been there as long as records date back. Whatever process created the Backrooms to begin with may be able to manipulate voidstone and create this rebar.
It is important to note that not all walls contain voidstone, so some walls can be tunneled through. Likewise, voidstone is not be present on all levels.
As the source of Wi-Fi has not been discovered, it is speculated that the source of Wi-Fi is located behind the voidstone walls, out of reach of any human.
Lights and machines within the levels continually produce heat. If there was no where for the heat to go, the rooms would heat up to hundreds of degrees. The voidstone serves as a heat reservoir, absorbing excess heat, keeping the levels at a stable temperature. The temperature of the voidstone varies between levels. For instance, the voidstone in Level 115 is -10°C and the voidstone in Level 3 is 18°C.
Rooms with equipment such as boilers or heaters can be significantly hotter than the surrounding voidstone base walls, analogous to how the interior of a house with a heater can be significantly warmer than the outside.
An infographic illustrating voidstone's presence levels is shown below. A cross-section of Level 0 is given as an example.
Cross-section of Level 0, demonstrating the presence of voidstone within the level.
Voidstone is rarely naturally exposed. If it is seen, then it almost certainly once had material covering it which was removed artificially.
Naming
Over the centuries, the various groups within the Backrooms referred to voidstone by different names. This presumably includes The Lost, but there are currently no known references to voidstone in recovered documentation. The first recorded use of the word “voidstone” was in 1952 in a diary of someone who later became a founding member of The Aiding Stragglers. The term was used by Aiding Stragglers members and its usage spread from there.
No matter how hard I try, I can't get out of this vile place! The further I walk, the more dangerous it gets, and I've tried smashing down the walls and floors with some pickaxes I found in these crates, but all that happens is that I open a hole into some kind of void. Except it is not a void, it is just some slippery black stone. Voidstone I guess? I tried breaking that too, but when pickaxe does not slip, my pick just shatters.
Practical Applications
Voidstone can be a nuisance as it limits how far walls can be tunneled through. However, wanderers have found ways to make use of it.
Infinite Source of Energy
As voidstone does not change in temperature when heat is removed, an infinite amount of heat energy can be extracted.
Buried deep behind the surface walls and ceilings in some levels, cubic cavities have been discovered with exposed voidstone walls. One of these walls will have a temperature above 100°C and the wall on the opposite side will be below 0°C.
Thermoelectric generators, devices that convert heat directly into electricity, will appear in these cavities. Conducting copper rods extend out from the generators and are pushed against the two voidstone walls, generating electricity from the temperature differential between the walls. Wires from these generators spread the electricity to lights and other equipment.
After several decades of measurements, these walls have had no measurable change in temperature. How these walls got to abnormally high and low temperatures to begin with is not known.
Various groups have constructed their own generators that extract energy from this source.
Mode of Transportation
As voidstone is frictionless, sliding objects across it is a fuel efficient way of transporting people and goods. In principle, a vacuum chamber with a voidstone floor could allow cargo to slide forever without propulsion. However, there are some technical limitations that have limited the usage of voidstone for this purpose.
To access the voidstone base floor, meters of surface-level flooring need to be dug through. There may be voidstone rebar, which is irremovable, leaving behind floating bars. It limits the height of vehicles, as vehicles that are too high will crash into these bars.
Wheels do not work on frictionless surfaces, so some other less convenient means of speeding up and slowing down vehicles is required, such as using linear induction motors, thrusters, or having wheels on the sides of the vehicles to push against walls. It is important for vehicles to be able to speed up and slow down easily to make their way through the twisted corridors.
For this reason, voidstone tracks have not been heavily used, which is also why The B.N.T.G. chose to construct train tracks instead in Level 2. However, The M.E.G. has built an experimental voidstone track in Level 1.
