This is a lightning storm in Minecraft, created by a repeating command block summoning in a LightningBolt entity 20 times a second. Shocking.
These are some infinite structures I created in Minecraft using a set of command blocks that clones itself, then a separate structure into a new location using the “/clone” command. These would extend all the way to the world border if I moved with it to keep the chunks loaded, and waited for a long time … Read moreInfinite Structures in Minecraft With Self-Replicating Command Blocks
Recently I was going through some of my old Minecraft worlds, and in this one (called “Water Tests”), I found huge strands of ice formed when I set up a command block that continually created ice above a thrown snowball. I played with it for about half an hour, during which this happened: