“Reader Jane wrote in to note that clouds look so nice and fluffy and lighter-than-air, so they certainly can’t weigh much. Right? When Peggy LeMone was in junior high, a friend’s dad pondered that same question, and she kept it in the back of her mind for years. Now all grown up, LeMone is a researcher at the National Center for Atmospheric Research, and she’s figured out an answer. Today, she shares her cloud-weighing technique with us.” w/ photos

“Zoologists have yet to unravel all of the genetic mysteries that lie behind the zebra’s signature striped suit. The alternating color pattern works well with its native environment, deflecting up to 70 percent of the heat that hits its body. The arrangement of the stripes adds another intriguing dimension to the animal’s biology since each zebra has a completely unique design. In particular, the stripes on its shoulders, or withers, contain the most individualized markings.” w/ photos

“Getting dizzy and fainting at the sight of someone else’s blood doesn’t seem to be the most, uh, evolutionarily appropriate response. How’s that going to help you when you’re trying to take down a buffalo? And despite it being relatively common — 3 to 4 percent of people suffer from blood phobia or a related disorder — the symptoms of it are totally different from most phobias: phobics’ blood pressure and heart rate will rise then drop when they see blood, as opposed to the just-heart-racing caused by most fears. So what gives?” w/ photos

“Depending on their playground status, people who took the bus to school as kids either have fond or not-so-fond memories of that childhood rite of passage: those giant leathery seats, the difficult to open vertical windows, and the flashing red stop sign that stuck out from the driver’s side. Perhaps the most easily recognizable aspect of the school bus is its unique yellow hue, which has remained the same for decades. Just how was this color chosen?” w/ photo

“In 2005, author David Foster Wallace was asked to give the commencement address to the 2005 graduating class of Kenyon College. However, the resulting speech didn’t become widely known until 3 years later, after his tragic death. It is, without a doubt, some of the best life advice we’ve ever come across, and perhaps the most simple and elegant explanation of the real value of education. We made this video, built around an abridged version of the original audio recording, with the hopes that the core message of the speech could reach a wider audience who might not have otherwise been interested. However, we encourage everyone to seek out the full speech (because, in this case, the book is definitely better than the movie).” — The Glossary

“Most of us are on the Internet on a daily basis and whether we like it or not, the Internet is affecting us. It changes how we think, how we work, and it even changes our brains.”

“In this Darwin was almost certainly wrong. In recent decades, scientists have offered several accounts of how the capacity for tears may have given early hominids an adaptive advantage. These range from the aquatic ape theory, according to which tears were an adaptation to saltwater living, to the notion that by blurring our vision tears may serve as a ‘white flag’ to potential aggressors – a signal that the crier is incapable of harm. Then there are the straightforward biological theories, such as the claim that tears evolved to keep the eye moist and free of harmful bacteria.” w/ photos

“A lot of people think that the distress signal is an abbreviation for ‘save our souls’ or ‘save our ship.’ But in reality, ‘save our souls’ and ‘save our ship’ are backronyms, and the letters don’t actually stand for anything. In fact, the signal isn’t even really supposed to be three individual letters. It’s just a continuous Morse code string of three dots, three dashes, and three dots all run together with no spaces or full stops (…—…). Since three dots form the letter “S” and three dashes form an “O” in International Morse code, though, the signal came to be called an “SOS” for the sake of convenience. That connection has led to the letters coming into their own as a visual distress signal divorced from Morse Code, and those in need of rescue sometimes spell them out on the ground to be seen from above.” w/ photo

“What are the greatest global threats to humanity? Are we on the verge of our own unexpected extinction? An international team of scientists, mathematicians and philosophers at Oxford University’s Future of Humanity Institute is investigating the biggest dangers. And they argue in a research paper, Existential Risk as a Global Priority, that international policymakers must pay serious attention to the reality of species-obliterating risks. Last year there were more academic papers published on snowboarding than human extinction. The Swedish-born director of the institute, Nick Bostrom, says the stakes couldn’t be higher. If we get it wrong, this could be humanity’s final century.” w/ photos

“New research suggests that the humble horse might not be quite such a willing worker as it often appears. A scientific study entitled ‘Are Horses Lazy?’ has found strong evidence which indicates the answer is ‘yes’ – or at least that they have little appetite for such research. The study, in the latest edition of the Journal of Veterinary Behavior, involved horses being given the option of a short or long period of exercise… Before the tests, the owners or handlers had been asked to rate whether they considered their animal lazy or energetic, on a scale of one to five. But the results showed that this had little impact on their preferences.” w/ photos