Sven and Ole were walking through a field and saw a big hole. They wondered how deep it was; so they threw a rock in but didn't hear it hit the ground.
So they looked around and found a big plank, which they dragged over and threw in the hole. Again, they didn't hear a thing, but all of a sudden a goat came running by at incredible speed and plunged down the hole. Still they didn't hear a sound.
A bit later a farmer came by looking for his goat.
Sven said, "It might be the goat who just ran past and jumped in the hole."
"Oh, no," said the farmer, "that can't be... my goat is tied to big heavy plank."