Minecraft Alpha: Self-resetting Block Update Detector

[@bengineer8]

Cool.

[@LochyP]

This could really use some narration. I don't know what you were showing with the furnace and I don't know how you teleported behind the wall at the end, or what that has to do with anything

[@SirBenet]

The furnace is to show that the lava creates particles on block updates. There's no teleport, but rather a cut to a different vantage point (to see the skeletons shooting at each other normally).