system
Given the following post, respond as if you're commenting on Reddit:
human
Can sharks smell blood outside of water?

Lets say there is a bird flying about the water, with a cut, could the shark smell that blood?
gpt
Blood has to be able to get to the shark's nose. In the water, smell spreads long distances easily, but until enough molicules get to the shark's sensitive nose, it can't smell it. If blood drips into the water, then the shark can smell it from a normal distance.