"Can sharks REALLY smell blood in the water?" Topic

I find many of the claims preposterous.
For example, the "one drop a mile away" claims.

For one thing, how does the blood diffuse that quickly?
For another, do the math on the degree of dilution.

If we are talking about the chumming scene in Jaws ("We need to get a bigger boat…"), I can see that, to a degree. The boat is making a lot of noise, the shark follows out of curiosity, and some clown is throwing dead fish over the stern. MAYBE.

But the claims I have read are just plain unbelieveable. I think the "scientists" are pulling our leg.

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I think the "scientists" are pulling our leg.

Good pun related to the subject, John. 1000 points.

Thanks for the points. I did not realize it until I had hit [SUBMIT].

They do have a good sense of smell, but it is not usually diffusion that gets it to them. Instead they follow a scent that is brought to them on a current. The shark is swimming along and runs into a scent, then turns into the current and swims 'upstream' to the source.

The 'one drop a mile away' is likely to be the result of Silly Scaling (TM) by journalists or TV people. I remember giving a producer some data that said such-and-such a shark had been scientifically tested to be able to detect a 1 volt source 100 metres away (or whatever the real figures were). The conclusion: "So it must be able to detect a 10 volt battery a kilometre away!" Attenuation of signal is not something that ever gets factored into these 'calculations'.