Carl Zimmer in his excellent blog, The Loom:
Whales are the biggest animals to ever live. Blue whales can get up to 160 tons–about as heavy as 2000 grown men. They are trailed in the rankings by the fin whale and a few other related species of whales. There are no lobsters in their ranks, no clams, no rodents. All these giants feed in much the same way. They swallow up water and filter it through fronds in their mouths called baleen. Most of the food they eat is tiny stuff, like krill and other small invertebrates. So some scientists have wondered how big whales manage to put enough tiny bits of food in their bodies to get to such huge sizes.
Unfortunately, whales dine out of sight, so scientists have had to tackle those questions with indirect clues. Jeremy Goldbogen, a biologist now at the University of British Columbia, has gathered all the clues he can, from data recorders carried by diving fin whales to video of baleen whales feeding near the ocean surface. To make sense of that data, he has worked with zoologist Robert Shadwick and ad paleontologist Nick Pyenson, also of UBC, as well as Jean Potvin, a physicist whose speciality is parachutes.
Yes. Parachutes. Let me explain.