Shark skin has long fascinated humans from fishers to physicists. That’s because shark scales have evolved into tiny three-dimensional, anvil-shaped structures called denticles that help these animals swim at furious speeds. Attacking Mako sharks, for example, have been clocked at over 70 km/h. By comparison, an Olympic sprint swimmer might reach just 5 km/h.The thinking among hydrodynamicists is that the strange shape of shark denticles must play a crucial role in shark locomotion. And if the ...read more
As it turns out, spacecraft aren’t immune to age. In November 2023, NASA’s 46-year-old Voyager 1 spacecraft started sending a stream of nonsense to Earth, spewing out signals without any morsel of meaning. Members of the Voyager 1 mission team are rushing to resolve the issue in the aging spacecraft and are relatively optimistic after receiving a more meaningful response from the spacecraft this month.But the ongoing breakdown in communication casts doubts on the durability of the probe and ...read more
Just as Earth revolves around the sun, so too does the moon revolve around Earth. Sometimes, when the angle is just right, the moon slides in front of Earth and ends up completely blocking the sun’s rays: simply put, this is a solar eclipse.Total solar eclipses look unnatural, like some divine harbinger of misfortune, though they are anything but. They are completely natural phenomena but rare, only occurring once every one to two years over select portions of the globe, drawing crowds of amaz ...read more
For the stressed and overworked, there might be nothing more relaxing than a spa. Beyond the cucumber slices and hot towels, these leisurely destinations carry a fascinating legacy that extends back to ancient times. Bathing in mineral springs — a feature of many historic spas — has been considered a medical and therapeutic treatment throughout the ages, spawning the proverbial phrase “taking the waters”. Today, this practice is known as balneotherapy. Some cities have made the most of ...read more
Dogs have long shown that they can respond to such instruction words as sit, fetch, and come. They have more difficulty differentiating between objects — say a Frisbee or a ball. Earlier research shows that, when asked to choose between two items, dogs pick the correct one about half the time — no better than a coin flip. But a new study shows dogs’ brains respond about as well as a human’s when presented with familiar versus unfamiliar words, according to a study in Current Biology.Mari ...read more