In Minecraft, a bubble elevator goes up primarily due to the placement of a specific block at the base of a vertical column of water source blocks: Soul Sand.
The Power of Soul Sand
The core mechanic behind an upward bubble elevator is the interaction between Soul Sand and water source blocks. When Soul Sand is placed directly underneath a column composed entirely of water source blocks, it generates upward-flowing bubble columns. These bubbles exert an upward force on any entity (players, mobs, items) that enters them, effectively pulling them vertically through the water column.
Essential: Water Source Blocks
For the bubble column to extend all the way from the Soul Sand at the bottom to the top of your elevator, every single block space in the vertical shaft must be filled with a water source block. Unlike flowing water (which is created when water spreads out), a source block will remain in place and feed the continuous stream of bubbles generated by the Soul Sand below. If there are any air blocks or flowing water blocks within the column, the bubble column will stop or become inconsistent.
Constructing the Elevator Column
Building a functional bubble elevator involves creating this enclosed vertical shaft and ensuring it's filled with water source blocks. This often requires specific building techniques to prevent water from flowing outwards. As seen in tutorials like the one referenced, builders often use blocks like glass or solid blocks for the walls and then employ items like signs, doors, or gates during construction.
- Using Signs: The reference mentions placing glass, breaking it, and replacing it with a sign. This technique is common in elevator construction. Placing a non-full block like a sign in a block space prevents water from flowing outwards into that space while still allowing water to occupy the block space above or next to it. This helps in creating enclosed spaces that can then be filled with water source blocks effectively, ensuring the integrity of the vertical water column needed for the Soul Sand's effect to work.
Up vs. Down: Soul Sand and Magma Blocks
It's worth noting the distinction between upward and downward bubble columns:
- Soul Sand: Creates upward bubble columns.
- Magma Blocks: Creates downward bubble columns (pulling entities down into the block).
Therefore, it is the presence of Soul Sand at the bottom that specifically makes a bubble elevator go up.
