Dog owners can sleep easy tonight because physicists have discovered how rapidly a wet dog should oscillate its body to dry its fur. Presumably, dogs already know. From the article: "Today we have an answer thanks to the pioneering work of Andrew Dickerson at the Georgia Institute of Technology in Atlanta and a few buddies. But more than that, their work generates an interesting new conundrum about the nature of shaken fur dynamics. Dickerson and co filmed a number of dogs shaking their fur and used the images to measure the period of oscillation of the dogs' skin. For a labrador retriever, this turns out to be 4.3 Hz."

Not that it will change anything, but researchers at Bristol University say that your dog might be a gloom-monger. In addition to the downer dogs, the study also found a few that seemed happy no matter how uncaring the world around them was. "We know that people's emotional states affect their judgments and that happy people are more likely to judge an ambiguous situation positively. What our study has shown is that this applies similarly to dogs," said professor Mike Mendl, an author of the study and head of animal welfare and behavior at Bristol University.