i finished reading homestuck from beginning to end a while ago and only one thing really bugs me. everything in homestuck with loose ends always makes sense after a while but what about grandpa harley? how is he alive with a flying ship???? and where did he go after the scratch??? this haunts me and for the life of me i cant remember if that was ever resolved or not. how did he manage to stuff jade's dreamself and yet that always existed in the past??? grandpa harely confuses me entirely!!!!!!!

Time in the Medium is not the same as it is on Earth.  There are teleporters in the Frog Temple that go to Prospit and Derse. Mind you that the Frog Temple is on the island that Grandpa Harley owns. Therefore he was free to use the teleporters and go between Earth and The Medium at will.