User blog comment:Scooter8pie/Brown Mob and the Colorwood Experiment/@comment-68.226.70.27-20120119224955/@comment-4583259-20120120154117

I agree - I tried exploding a brown mob at the bottom of the world in Version_1.8.0 and it didn't work. A few blocks to the sides got blown away, but the bottom of the world stayed.