Ever since the Industrial Revolution, civilization has been powered mostly by fossil fuels. But what sources of energy did ancient civilizations use, and how sustainable were those?How Ancient Civilizations Harnessed Solar EnergyThe most ubiquitous and renewable source of energy is, of course, the sun. People have long used solar energy — and not just for growing crops. According to Let It Shine: The 6,000-Year Story of Solar Energy by John Perlin, excavations of Neolithic Chinese villages sho ...read more

If breaking a mirror actually brought bad luck, surely the government would have public service announcements regarding reflecting-glass safety. And if tossing salt over the left shoulder after spilling a shaker was truly effective, schools would host regular drills.Superstitions don’t make sense. Yet, many logical people wince if they break a mirror. They avoid the number 13 or hold their breath when passing cemeteries.Social scientists are learning more about the psychology behind superstiti ...read more

We’ve known for some time now that Homo sapiens and Neanderthals, also known as archaic humans, interbred before Neanderthals went extinct around 40,000 years ago. In fact, in some ways, Neanderthals never went extinct because modern humans are still made up of around 3 percent Neanderthal DNA.But many questions still linger around where these two groups got together and what their interbreeding might have looked like.Previous research has highlighted a key migration point for H. sapiens after ...read more

Sometimes, resemblances between parent and child or siblings can be uncanny. Other times, such resemblances can pop up between aunt and niece or grandfather and grandchild. And still, other times, resemblances don’t exist at all.One child may look like one parent, and their sibling may look like the other parent. Sometimes, certain facial traits seem to jump from one generation to the next repeatedly.All of these outcomes lead us to wonder what impacts facial features. What part of our DNA is ...read more

Humans derive their sense of taste from tastebuds, which allow us to identify bitter, salty, sour, and sweet. In 1990, umami was identified as the fifth taste. Many animals also get their sense of taste through tastebuds, although there are other methods in the animal kingdom for identifying taste. Let’s take a look. What Animals Have the Best and Worst Sense of Taste?(Credit: MEDIAIMAG/Shutterstock)The animal with the best sense of taste is the catfish. Possessing over 100,000 (and in some c ...read more

Many fish owners have tapped on their aquarium and hoped little Bubbles was merely taking a nap inside the tiny castle.It can be difficult to determine whether a fish is sleeping, and even scientists have struggled to understand the sleep process of fish in the past.In recent years, technology has made it possible for researchers to scan fish brains and learn how they snooze.Do Fish Sleep?“Fish sleep, but not the same as humans or mammals,” says Jared Guthridge, the aquarium curator at the A ...read more

One of the curious features of the laws of physics is that many of them seem to be the result of the bulk behavior of many much smaller components. The atoms and molecules in a gas, for example, move at a huge range of velocities. When constrained in a container, these particles continually strike the surface creating a force. But it is not necessary to know the velocities of all the particles to determine this force. Instead, their influence averages out into a predictable and measurable bulk p ...read more

The cell is a biochemical factory of immense complexity. As fundamental units of life, cells harvest energy from the environment and use it to synthesize complex molecular machinery, to build replicas of themselves and to move. This is a 4-billion-year-old trick that even today mystifies biologists who struggle to understand the processes and principles at work.To change this, life scientists have modeled cells at various levels of detail. These models can simulate some important biomolecular pr ...read more

A large and unique discovery in Spain reveals how sauropods may have dispersed across Asia and Europe before dinosaurs went extinct.The well-preserved bones of the newly named Qunkasaura have improved paleontologists’ knowledge of dinosaurs in Europe during the Late Cretaceous.“Qunkasaura was one of the most outstanding specimens in our quarry,” says Pedro Mocho, a paleontologist at the University of Lisbon in Portugal.How Was Qunkasaura Discovered?(Credit: GBE-UNED) General view of the ...read more

A rare, nearly complete fossil of an extinct North American porcupine helped me and my colleagues solve a decades-long debate about how the modern North American porcupine evolved from its ancestors.Published in Current Biology, our paper argues that North American porcupine ancestors may well date back 10 million years, but they wouldn’t be recognizable until about 8 million years later.By comparing the bone structure of porcupines across North America and South America, we determined that fo ...read more