A chemist, a biologist and a quantum physicist go surfing.
Having developed a paranoid sense for lab safety precautions, the chemist is worried about jumping into water with unknown impurities.
The biologist knows the local marine wildlife and assures him that the water is perfectly safe for living beings, with plenty of fishes and squids present.
The physicist hears that and asks: "How are we going to surf if there's squids, wouldn't they collapse our waves?"