Dig into your pockets and pull out some change. If you’re in the U.S., you’ll probably find some crumpled cash and a couple not-so-shiny coins. They may not look like much, but what you’re holding is a handful of history.Your beaten-up buck is part of the long line of dollar bills printed in the U.S. since 1862. The quarter was introduced in 1796, and the penny appeared three years prior, in 1793. You probably have some in your possession, abandoned at the bottom of your bag. Of course, th ...read more
Throughout history, specific technologies have revolutionized the way we live, work and play. This has often occurred gradually, but occasionally through dramatic, sweeping changes in society. The technology behind the industrial revolution -- the steam engine, the spinning jenny and the cotton engine, for example -- accelerated economic growth by an order of magnitude, creating an explosion of innovation that still reverberates around the planet.By contrast, other technologies have had more mod ...read more
A passenger jet flies at about 575 mph once it’s at cruising altitude. That’s nearly nine times faster than a car might typically be cruising on the highway. So why does a plane in flight look like it’s just inching across the sky?I am an aerospace educator who relies on the laws of physics when teaching about aircraft. These same principles of physics help explain why looks can be deceiving when it comes to how fast an object is moving.Moving against a featureless backgroundIf you watch ...read more
Ever go to the movies or a rock concert and been blasted by the sound? You may not realize it while it’s happening, but ongoing exposure to loud sounds at these venues can damage your hearing.Our ears are highly sensitive to loud noise. Even very short exposures to high-level sounds – that’s anything above 132 decibels – can cause permanent hearing loss for some people. That’s true even if it’s just a brief blast; a single gunshot or fireworks explosion can cause immediate damage to ...read more
Modern and early birds, plus feathered dinosaurs, have all sported feathers made of the same material, according to a new study.The researchers investigated 125-million-year-old feathers from a dinosaur and an early bird to identify the proteins present. Both lived in China during the Early Cretaceous Period, about 25 million years after the first birds evolved.Established science holds that they should have found spiral-shaped alpha proteins, which set ancient feathers apart from modern ones.†...read more
Author Vishay SinghPosted on Categories Discover Magazine