# How would an invisible wall work in theory

## World barrier

This article covers the world barrier. For the barrier as a block, see Barrier.
A corner of the world barrier. You can still see a narrow strip of land until the world ends

The World barrier is a clearly visible curtain that lies at the coordinates x = ± 29,999,983 or z = ± 29,999,983.

You can teleport yourself into the 1 chunk wide strip of land outside the world barrier and walk back into the world. You cannot teleport or walk to a position outside the world, behind the coordinates ± 29,999,999. There is an invisible wall there or air is solid there and coordinates from 30,000,000 are not accepted.

### Sense 

Too large redstone lines and non-falling gravity-dependent blocks near the world barrier
A falling block near the world barrier falls 0.5 blocks offset

The existence of the world barrier has a technical reason, because the game basically has to somehow save all values, either during the game in the main memory or when saving the game. There are different data types for the different values, e.g. small numbers (Integer), large numbers (Long), Floating point numbers (Double) etc. Each data type has a precisely defined maximum size. Values ​​that are larger cannot be saved. There must therefore be a limit, because when this number is reached, it jumps back to zero and the world is generated incorrectly.

Another problem is calculating with large numbers. Example: on many calculators. But it should be 0.0000333 ... Such rounding errors when calculating with large X or Z coordinates can lead to a wide variety of problems in the game. Therefore, a special treatment for extremely large coordinates was introduced, namely the world barrier. It prevents X or Z coordinates that are greater than 30,000,000 from coming into play.

But the line cannot be drawn that precisely. Even with coordinates that are smaller than the limit values ​​- sometimes even 10,000,000 - internal calculations can lead to strange effects. Example: Redstone lines can be four times the size there, gravity-dependent blocks may no longer fall, ignited TNT jumps strangely, trolleys are not placed correctly, etc.

Since these effects also depend on the computer's hardware, they can appear on some computers and other computers may not exhibit these effects.

### Properties 

The world barrier is a widely visible curtain made of an obliquely striped, slowly moving texture. In the void above and below the world, the curtain cannot be seen, but the world barrier is there, too. The world barrier can be seen approx. 50 blocks away in the open landscape. If the view of the world barrier is obscured, the field of vision begins to turn red as a warning when you approach it within 5 blocks (but only with the graphic setting "Nice"). If you try to cross a world barrier (even in creative mode), it behaves like a wall. You can only cross the world barrier in spectator mode.

With the command you can set a world barrier yourself, which is intended for the creation of adventure worlds.

• If this world barrier is subsequently placed in a world that has already been generated, the world behind the barrier remains or is also regenerated behind the barrier when you approach it.
• Players and creatures can get outside of the world by changing the world barrier or because they are teleported to an appropriate position (also by Ender pearls). Players can hardly interact with the world there, i.e. they cannot take down or place blocks and only operate a few blocks, e.g. rotate pressure plate, cart, boat and objects in a frame. You should run back into the world as quickly as possible, because if you are outside the so-called integrity range, which is 5 blocks by default, you will suffer damage in survival mode (not in creative mode) until you die. The default damage is 0.2 () for each block beyond the integrity area. Creatures take no damage.
• You cannot push blocks behind the world barrier with a piston, they get stuck on the barrier.
• There is only one world barrier curtain. If you set a world barrier yourself, the curtain of the standard world barrier at 29,999,983 disappears.
• It is not possible to set several world barrier areas that exist at the same time.
• You can also move a world barrier you have set yourself and specify a time for the move process. Then it will show red as it approaches and green as it moves away. You can also set whether and when players are warned when approaching a shifting world barrier.

### Limits in the Nether and the end

The conditions also apply to the Nether and the End. There, too, there is a world barrier from x / z = ± 29,999,983 blocks, although there is one block in the Nether and 8 blocks in the upper world.

### Forerunners of the world barrier in older versions 

In the Classic and Indev phases, world sizes of 128 × 128 × 64 (small), 256×256×64 (medium) and 512 × 512 × 64 (huge) to be created.

With the Infdev phase, the infinity of the world was introduced. As soon as you approach a border, new areas (chunks) are generated. The world can theoretically become infinitely large. In practice, however, this is limited by problems in the calculation with large coordinates: From ± 12,550,821, the world generation no longer worked properly and created patchy areas without a correct landscape. This was not really wanted, but Notch found it fitting that the world was becoming unpredictable at its edges. The region was called "Far Lands".

As the world generation with Beta1.8(Beta 1.8-pre1) was changed, the Far Lands also disappeared as a side effect. Instead, the playable world ended abruptly at ± 30,000,000 blocks or 1,875,000 chunks. The areas behind it were also generated, but the light calculation no longer worked there. The chunks only contained blocks of grass, earth, stone, bedrock, water and lava (rarely also mycelium and ice). There were no plants or creatures. Trees on the border had cut leaves. But it all just looked like this, because if you entered this area, you fell into the void because the blocks weren't solid. There were many other display and functional errors, including game crashes, when experimenting in these areas.

The bugs were not fixed because it was not intended to play there. But due to program changes in the following Minecraft versions, especially changes to the world generation, the phenomena changed from 30,000,000, so that some errors disappeared and new ones arose.

Finally, with the full version 1.7(13w37a) introduced an invisible wall at 30,000,000. In the area behind this world barrier, the usual 12 chunks were generated in each direction around the player with landscape including caves, but all types of structures such as trees or mines were missing. You could see this landscape outside the border, but not step on it. The world barrier had no upper or lower limit; H. You couldn't fly into the void in creative mode over the maximum height of 256 blocks and then move over the world barrier. It was the same if you dug your way to level 0 and tried to fly under the world barrier in the lower void. Behind the world barrier, all the blocks were solid, including air. Therefore, if you teleported to an area outside the world barrier, you couldn't move there. The lighting of the bedrock layer below the world also changed behind the world barrier.

### Trivia

• Since the player's eye level is 1.62 blocks, 1 block is usually considered to be equivalent to 1 (cubic) meter. 30,000,000 blocks in each direction would then correspond to a distance of 60,000 km from world border to world border. If you walked around the world, you would only have covered about 40,000 km. In terms of area, the difference is even greater: the square Minecraft world has a maximum accessible area of ​​60,000 × 60,000 km or 3.6 billion km². This corresponds to seven times the roughly spherical surface of the earth, which is about 510 million km² in size. This fact was already important to Notch in the Infdev phase[1]when automatic expansion of the world was introduced.
• The end of the world at 30,000,000 should not be viewed as a restriction, on the contrary: an area of ​​10,000 × 10,000 blocks is usually completely sufficient for a player and the surrounding area often remains undiscovered.
• In total, in a Minecraft world with a height of 256 blocks, up to 921.6 quadrillion (921.6 × 1015) Give blocks.
• A completely explored Minecraft world would roughly require several dozen petabytes of storage space (1 petabyte = 1,000 terabytes = 1,000,000 gigabytes) and would therefore completely fill many thousands of conventional hard drives. The largest single hard drive is currently 20 terabytes (October 2020)[2][3]. (Calculation: A completely explored region file covers an area of ​​512 × 512 blocks and can be up to 5 MB in size, a complete Minecraft world consists of 13.7 billion region files.)
• If the entire world population (7.5 billion people) were to play in a Minecraft world, everyone would still have a large area averaging about 693 × 693 blocks (480,000 m²) to themselves. That is exactly half a square kilometer, i.e. the population density would be 2.1 players per square kilometer with a full occupation. That is slightly more than the population density of the most sparsely populated state in the world, Mongolia (1.9 inhabitants per square kilometer). For comparison: In Germany, an average of 230 people live in one square kilometer.[4]
• To get an idea of ​​the size of the Minecraft world, you can see it in this Flash animation compared to the earth and some other objects. At zoom setting it is 107,6 visible.

### Gallery 

• Standard world barrier in a mine: there are no more blocks to be seen behind the curtain

• In the end you can see the world barrier through the radiant walls

• A self-imposed world barrier at night

• A self-set world barrier in the Nether

• Before version 1.8: The lighting of the bedrock in front of and behind the world barrier seen from the void

• The display of the world barrier stops at the 256-block limit at the top, but the barrier also exists invisibly in higher levels

• This is also the case below the bedrock level

• You can attach blocks behind the barrier to other blocks in front of the barrier, but you cannot dismantle them

• If you place a gravity-dependent block behind the barrier in older versions, it is immediately destroyed, but the drop does not fall

• You cannot spawn animals outside the world barrier, but you can with a launcher

### History 

Version history of the Java Edition
Full version 1.3.1(12w25a)
• The command accepts coordinates as the first command, for X and Z coordinates the maximum possible input is ± 30,000,000
Full version 1.7(13w37a)
• World barrier at X / Z = ± 30,000,000 added
• It is invisible and cannot be crossed because all blocks behind the barrier (including air) are solid
• The world generation takes place quite normally behind the barrier, only landscape features such as caves are not generated
Full version 1.8
14w02a No more new chunks are generated behind the world barrier, instead the emptiness is located there The world barrier has an animated texture and is no longer invisibleIn the Nether the world barrier is at one eighth (X / Z = ± 3.750.000) of the coordinates of the upper worldThe world barriers of the upper world, the nether and the end can be changed with the command, but they cannot be expanded larger than X / Z = ± 30,000,000 (or in the nether not larger than X / Z = ± 3,750,000) The world barrier is now one chunk before the end of the world at X / Z = ± 2,999,983 If you approach the world barrier, the field of vision is colored red as a warningIn the Nether the world barrier is again at the same coordinates as in the upper world If you get outside the world barrier, you can run back Funnels no longer work behind world barriers Creatures no longer take damage outside of the world barrier
Full version 1.9
15w37a Chunks are generated again behind the world barrier, but you still cannot enter them