The scale of a whale’s hearing is hard to grapple with. There’s the spatial vastness, of course, but also an expanse of time. Underwater, sound waves take just under a minute to cover 50 miles. If a whale hears the song of another whale from a distance of 1,500 miles, it’s really listening back in time by about half an hour, like an astronomer gazing upon the ancient light of a distant star. If a whale is trying to sense a mountain 500 miles away, it has to somehow connect its own call with an echo that arrives 10 minutes later. That might seem preposterous, but consider that a blue whale’s
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