I made a lag machine in my world and I was trying to crash my world to see if I could get a chunk error. but it wouldn't crash so I just left the world. Then the next day I came back to the world (keep in mind I did not leave it running all night) and stopped the machine and there was this sand that was just floating idk why it was. So I pushed it with a piston and it still didn't break or die it just moved out of the way, so I dug a hole down to the void and it did not break still while it was in the void. So I did /kill @e and it still didn't break and before I dug that hole I set it on fire to see if it would break and it didn't.

One more thing, It was like not floating it was in a state where it was not a block.