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

Month by month, and season by season, global heating records continue to fall.After 2023 came in as warmest year (it wasn't even close), and 2024 started with record high temperatures, it should come as no surprise that February was weirdly warm too. The red line in the graph above shows the evolution of Earth's average surface air temperature for the year so far. The orange line shows the record for 2023, and the dashed one shows the average for 1991-2020. All years between 1940 and 2023 are de ...read more

(Credit: NASA, ESA, CSA, Brant Robertson (UC Santa Cruz), Ben Johnson (CfA), Sandro Tacchella (Cambridge), Marcia Rieke (University of Arizona), Daniel Eisenstein (CfA))Since December 2021, the James Webb Space Telescope (JWST) has unlocked various secrets of our universe. From providing newer images of galaxies taken by the Hubble Space Telescope to enlightening experts on supernova remnants and peering into the early universe, the spacecraft has already discovered so much.Below are the latest ...read more

Up to half a century ago, researchers established that writing originated in Mesopotamia in the fourth millennium B.C., and spread to the rest of the world, adapting to different languages. Since the 1970s, however, the decipherment of Maya and further discoveries has suggested that humans invented writing not once, but four separate times: in Mesopotamia, Egypt, China, and Mesoamerica. In a recent study published in Nature, researchers at the University of Bologna in Italy have dated the wood o ...read more

“You don’t count your children until the measles has passed.” Dr. Samuel Katz, one of the pioneers of the first measles vaccine in the late 1950s to early 1960s, regularly heard this tragic statement from parents in countries where the measles vaccine was not yet available, because they were so accustomed to losing their children to measles.I am a pediatrician and preventive medicine physician, and I have anxiously watched measles cases rise worldwide while vaccination rates have dropped s ...read more

For many people in the ancient world, life was no casual stroll around the Forum. Today, many diseases can be treated with modern medicine or prevented entirely, thanks to the development of myriad vaccines to help rid us of the risk of infection (though major inequalities still mean such lifesaving shots are not available to all). In ancient times, however, these advances simply were not available, making disease an ever present and deadly risk. Kyle Harper, professor of classics and letters at ...read more

Vertigo is more than just feeling dizzy. It is a symptom characterized by a sensation of spinning or a feeling of motion when no actual movement occurs. It often manifests as a perception that either the individual or their surroundings are spinning or tilting, leading to a sense of disorientation and imbalance. All of this is in addition to feeling dizzy.  “First, it is important to outline the differences between vertigo and dizziness. While these words are often used interchangeably, they ...read more