By many estimations, the Amazon may be the world's mightiest river. It has the largest drainage basin in the world and is also the largest in terms of water volume.Indigenous people have also been exploring the river for millennia. In more recent centuries, other explorers have sought to find the ultimate source of South America’s great river. These have included everything from European conquistadors nearly five centuries ago to more recent scientific explorations using modern technology.Whil ...read more

Grief is one of the great paradoxes of the human condition. It’s something that, alas, everyone will experience — and more than once in the average lifetime. And yet, despite its commonality, that experience will be different for everyone. In fact, it can be different each time the same person experiences it, depending on the type of loss and when it happens. Dealing with grief has stages, and each stage has a different impact for everyone.The Stages of GriefAlthough the process of grief is ...read more

Throughout history, jewelry has been a symbol of status, wealth, and power. Though the wealthiest may have adorned themselves in precious gems, stones, and metals, in the ancient world, jewelry was used for a variety of reasons — and came in many different shapes and sizes. The tomb of one Queen Puabi — discovered in the Royal Cemetery of Ur in modern-day Iraq — is a striking example of the riches worn by ancient elites. Her tomb contained magnificent pieces including a headdress of gold l ...read more

Researchers have spent years grappling with the uncertain details of archaic humans’ first entry into Europe, but stone tools created about 1.4 million years ago may offer important insight. The tools were discovered at the Korolevo archaeological site near Ukraine’s border with Romania, and have now considered the oldest known artifacts in Europe made by ancient humans. A team of archaeologists recently dated the tools and published their findings in Nature, delivering progress on critical ...read more

For people with neurodivergence, pharmaceuticals can help manage or reduce symptoms. People with Attention-Deficit/Hyperactivity Disorder (ADHD), for example, may benefit from medication that helps them focus.Increasingly, scientists are also seeing benefits to nutraceuticals. Nutraceuticals (a combo of nutrition and pharmaceutical) are dietary supplements that provide vitamins or minerals. Nutraceuticals might not replace medication, but researchers are finding they can help people with neurodi ...read more

When astronomers study the rotation of distant galaxies, they immediately come up against a puzzle. The stars are held together by gravity, which prevents them being slung into intergalactic space as the galaxies rotate. Indeed, astronomers can calculate the amount of gravity based on the mass of the stars they can see. The puzzle is that the outermost parts of these galaxies are moving too quickly. There does not seem to be enough of this mass to stop these stars from flying away. The fact that ...read more

In ancient cultures, solar eclipses were seen as apocalyptic prophecies, omens of the displeasure of the gods, periodic celestial coincidences, or some mixture of all three. The events stopped wars, made temporary kings, and perhaps founded ancient cities.Solar eclipses may strike awe or even fear in people, especially those less versed in astronomy. After all, they can turn an ordinary bright, clear day into relative darkness as the moon slowly blocks the sun. In ancient times, people could hav ...read more

One-point-two kilograms per cubic meter. Why is this number significant? It’s the approximate average density, or mass per volume, of the air at sea level. As you might expect, this mass pales in comparison to that of water, which is roughly 800 times denser than the atmosphere above it. Despite this, air has enough heft to ensure that high-speed hurricane winds can lift whole houses clean off the ground. And when pushed through a jet engine, it can hold a 640-ton airplane aloft — no mean f ...read more

A good night’s sleep is becoming a rare treasure. According to the National Institutes of Health (NIH), about one in three adults in the United States doesn’t get enough sleep, and an estimated 50 to 70 million Americans have chronic sleep disorders.Many people struggling to get enough sleep turn to nutritional supplements for help. Common sleep supplements are melatonin, valerian, and the currently trending ashwagandha, a plant used in traditional Ayurvedic medicine, an ancient Indian syste ...read more

Equipped with the latest gear and a thirst for adventure, mountaineers embrace the perils that come with conquering the world’s highest peaks. Yet, even those who tread more cautiously at high altitude are not immune from the health hazards waiting in the thin air above.Altitude sickness, which most commonly refers to acute mountain sickness, presents a significant challenge to those traveling to and adventuring in high-altitude destinations. Its symptoms can range from mildly annoying to inca ...read more