Dental problems have tormented humans for ages, but the recent discovery and analysis of two 4,000-year-old teeth reveal how the bacteria populating our mouths have changed over time. The teeth, found in a limestone cave in Killuragh, County Limerick, Ireland, along with other skeletal remains, have helped researchers piece together a timeline of oral health. Their findings have been published in a new paper released in Molecular Biology and Evolution. Although fossilized teeth and their DNA ar ...read more

More than 6 million Americans are living with Alzheimer's disease; a figure experts project to double by the year 2050. Alzheimer’s is the seventh leading cause of death and the number one cause of dementia in the U.S.While lifestyle factors like eating brain-boosting foods and managing high blood pressure can help prevent it, many adults are still at high risk. However, recent research suggests another lifestyle habit — the ancient yet powerful practice of yoga — may be especially effecti ...read more

Cataract surgery is one of the most popular and commonly performed procedures in the world. The vast majority of patients have excellent outcomes with few complications.Here are the numbers:As ophthalmologists who have performed thousands of these procedures, we know that many patients have misconceptions about both cataracts and the surgery. For example, some think a cataract is a growth on the eye’s surface.We like to compare a cataract with the frosted glass of a bathroom window, where ligh ...read more

Ancient megalithic temples dating back to the European Stone Age drive popular imagination. Places like Stonehenge give rise to theories that include everything from ancient druids to signs of the influence of aliens on ancient human civilizations.The reality is we often know relatively little about these neolithic megastructures. The Near East saw the development of cities like Göbekli Tepe more than 10,000 years ago. At the same time, the Fertile Valley gave birth to various cities and civili ...read more

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

A new instrument aboard NASA’s Europa Clipper may be sensitive enough to detect any life emanating from the plumes of far-off icy moons like Saturn's Enceladus and Jupiter's Europa. Over the years, scientists have found evidence of water underneath both moon’s frozen surfaces.The instrument dubbed the SUrface Dust Analyzer (SUDA) on the Europa Clipper, can detect even the slightest biological signatures in one out of hundreds of thousands of grains of ice from plumes on Europa and Enceladus. ...read more