No doubt there are still people--especially older ones, long out of public school--who haven't heard of black smokers and who believe (as everyone used to) that all of life on earth depends directly or indirectly on photosynthesis. Though one can never overestimate the power of public education in America to get things wrong, I'm pretty sure that younger people now know better, because the basic biology textbooks had to be rewritten after Robert Ballard and his colleagues discovered, in 1979, undersea ecosystems that were clustered around hydrothermal vents ("black smokers") and were using chemical energy, not light energy, to sustain life. Though I see in glancing back at the published text via Google Books (I read an advance draft) that Ballard mentions that chemosynthetic bacteria were already known to exist in rare, isolated instances, I think it's still true that Ballard's discovery transformed biology, because it was now possible to imagine that life itself had originated in this way, in the depths of the oceans, and that photosynthesis arose later, or at least independently.
That's only one of the ways in which Ballard has contributed to altering our understanding of the planet we live on, much of which is summarized in this book. The publisher's summary is pretty accurate, and I won't recap it, but I can take issue with its claim that Ballard has done more than any other man to cast light on the eternal darkness of the deep sea. You might draw that conclusion, and it's not unreasonable, but the tale Ballard tells makes clear that the work of discovery in the oceans isn't solitary, even if it depends on singular minds for its progress. You'd do better to conclude--and this is probably what he'd hope, for he's a modest man--that he didn't find the Titanic alone, that Beebe and Barton and the Picards and many others were a part of it.
I already knew the outlines of this story, having learned it in bits and pieces over the years, but having it all recounted succinctly in one book was a refreshing reminder. Though the temptation to put simplifying labels on things is regrettable, you wouldn't be amiss in calling the last 100 years the century of oceanography. Read Ballard's book and you'll know why.