EarthDate

Five centuries ago, the last emperor of the Aztecs drank a full gallon each day of a coveted beverage, rich in vitamins and caffeine. The Aztec word for it: xocolatl Chocolate.Just like today’s chocolate drinks, his was made from the ground seeds of the cacao fruit. The Olmecs and Mayans before him domesticated the cacao, an understory tree from Ecuador.There and in Mexico, it thrived – under very specific conditions: Steady warm temperatures. Abundant rainfall. Well drained volcanic soil, high in minerals.When the cacao tree blooms, its flowers must be pollinated within 48 hours, by ants or small flies. As few as 20% of pollinated flowers produce fruit. And those fruits hold only a handful of seeds, which must be fermented to mellow their bitter taste before they’re fit for consumption.Mexican civilizations mixed their cacao with water, chilis, and spices. European invaders added sugar and milk to make chocolate bars.They took the cacao to their island colonies and to Africa, where growing conditions mimicked Mesoamerica.Today, rising heat, changing rainfall, deforestation, and overproduction jeopardize the global cacao trade.But choco-holics don’t despair. Scientists are working with cacao farmers to develop new hybrids and sustainable farming practices to keep this sweet treat with us for centuries to come.

In 1984, an engineer walked into a nuclear power plant under construction and set off radiation alarms. But there was no nuclear material yet on site. Where was the radiation coming from?Testing revealed the man was carrying it, on his clothes. Where did he become so contaminated? Turns out, at home.Scientists visited his house and found levels of radon gas 600 times higher than normal – the highest level ever measured inside a building.They immediately moved the man and his family out. Then began testing ways to mitigate the gas.Radon starts as uranium, which decays to become other elements and eventually radon -- the only element in that chain that occurs naturally as a gas.It’s odorless, colorless…and common, in small quantities, in air, water, and soil -- especially above bedrock that contains trace amounts of uranium.But there, it can leach into basements where it concentrates and becomes a health hazard. Radon is the leading cause of lung cancer in non-smokers – and is even more dangerous to smokers.A quick Google search can tell you if your area is prone to indoor radon accumulation. If so, buy a do-it-yourself testing kit. If you find high levels, hire a professional. They may recommend sealing all cracks in basement floors and walls, or ventilating under the foundation.With some simple precautions, you’ll be much safer.

Humans have lost most of our body hair, but the beard has stubbornly remained – though anthropologists can find no function for it.Perhaps that’s why men have been grooming it, or removing it, for thousands of years.Early cave paintings show men with smooth faces. Archeologists have found flint ‘razors’ they may have used to shave. And shell ‘tweezers’ they may have used to pluck off their beards. Ouch!The Egyptians were first to engage in elaborate shaving rituals. Facial hair was considered unclean, and men used copper razors or caustic chemicals to burn off their beards. Ouch again!Centuries later, Alexander the Great’s soldiers wore beards -- until he ordered them gone. Greeks reversed that tradition. For them, beards represented maturity and wisdom. The Romans reversed things again, and civilized men shaved or went to barber shops.Through the Middle Ages, beards came and went with the styles of influential leaders. Christian priests remained clean-shaven, to separate themselves from rabbis and Muslim clerics, who often had beards.In the 20th century, in the U.S. and Europe, shaving became synonymous with uprightness and business success. In the 21st century, things changed again, as beards reflect individual style and even environmental sustainability – avoiding the waste of disposable shaving products.If you’re wondering ‘to beard or not to beard,’ there’s no right answer. Wait a while and styles may change anyway!

Volcanoes often form where tectonic plates collide or pull apart. But sometimes they’ll form in the middle of plates, due to geologic hotspots.A hotspot is a plume of hot mantle that rises from within Earth, and heats, expands and deforms the crust above it, to create mountains, volcanoes or volcanic islands.The classic example is the chain of Hawaiian Islands, which formed as the Pacific plate traveled across a hotspot.Scientists always thought hotspots were stationary, while tectonic plates moved over them. But new research from beneath the Indian Ocean has challenged that idea.There, an undersea mountain range runs north-south for 3000 miles, along the 90-degree East longitudinal line.This long ridge was formed by a hotspot—but scientists studying the age and geologic makeup of each mountain on the chain realized they grew faster than could be possible by the plate alone moving.The hotspot must also have moved, possibly by hundreds of miles.This simple discovery will cause us to rethink hotspots and volcano formation, all over the world.It may turn out that other well-studied hotspots, like those beneath Iceland and Yellowstone, are moving too. Which could help us better understand the geothermal and volcanic activity there.And that’s how science works. It’s always on the move—sort of like hotspots.

Rare Earth Elements, or REEs, are a group of 17 trace metals that play important roles in the electronics we rely on daily. Their properties are so unique, they’re not replaceable.But their current supply is almost completely controlled by China, which creates shortages and security challenges. So, researchers are looking for domestic sources—and have found a surprising one: coal ash.When coal is burned at a power plant, it’s reduced to gases and about 10 percent of its weight in ash. In that ash, the trace metals from the coal become concentrated.Scientists from the Bureau of Economic Geology first recognized that coal ash could be a source for REEs.When they surveyed the ash produced by U.S. coal plants since 1950, they found 35 million tons that could be available for REE recovery. It’s currently stored in landfills and retaining ponds, mostly near the power plants.There are different concentrations of REEs in the ash. Eastern coal has the highest concentration, and Western coal the lowest—but western coal’s simpler molecular structure could allow more REEs to be recovered.The next step is to set up pilot projects to test the process, its energy requirements and environmental impacts.The preliminary studies look promising, offering a chance to build a domestic industry in Rare Earth Elements, while building better long-term storage for the coal ash. A technology win-win!

Birds have very large brains for their body size. New research is helping scientists understand how they work, and came to be.One part of a bird’s brain, the cerebellum, controls their amazing flight capabilities – their spatial awareness, allowing sudden direction changes through tree branches, or their ability to chart migration over thousands of miles.PET scans taken pre- and post-flight have shown very high brain activity in the cerebellum, especially the neural pathways connected to the eyes.CT scans of the skulls of modern birds and their fossil ancestors help explain how their brains evolved.The brains of early birds stayed the same size, as their bodies shrank. The brains of many bird families, like crows and parrots, then began to grow even larger.Island, nocturnal and insect-eating birds also grew larger brains, to manage difficult environments and chase flying prey.To control what birds do when not flying—building elaborate nests, singing complex songs, even solving puzzles—requires another part of the brain: the cerebrum.Other early bird fossils show that the cerebrum grew in size first, while the sophisticated flight anatomy, and the cerebellum to control it, developed later.Taken together, their cerebrum and cerebellum make a remarkable brain, which gives birds their even more remarkable qualities.So if anyone ever calls you a bird brain… well, say thank you!

On the east coast of the Yucatan Peninsula lie the wetlands of Belize. Swampy, hot and full of mosquitoes, these are unappealing places.But when they dry out each season, visitors noticed earthen banks that cut across the marsh.They thought these were water gathering facilities created by the Maya, who populated Belize centuries ago.Then carbon dating revealed they were at least a thousand years older. What could they be?When extended drought dried the swamps long enough for detailed field work, archeologists used new technology to learn more.With lidar—laser technology that can create detailed topographic images—they could ‘see through’ swamp vegetation. With drones, they could photograph difficult areas to reach.Combined, these allowed them to build a detailed 3D map of the area, revealing a vast, zig-zag network of channels and pools.In the wet season, when waters rose, ocean fish and other marine life would stream into the wetlands to spawn. When the dry season came, the channels would guide the fish into holding ponds for further growth and easy capture.This was a sophisticated system of aquaculture, centuries before the Maya.The scientists estimate it allowed as many as 15,000 people to live in and around the swamps, which they had re-engineered for their needs.These clever swamp dwellers may be the cultural predecessors of the great civilizations of Mesoamerica.

Animals evolved their colors to be sexy. But mostly, to be dangerous.Amphibians, reptiles, fish, insects, birds and even mammals sometimes use bright colors to attract mates.Think of the iridescent plumage of peacocks. Or the bright greens, yellows and oranges of a male iguana.But animals are about five times as likely to use bold color—especially red, yellow, black and white—to warn predators that they’re poisonous, foul-smelling or bad tasting.Think of the red hourglass on the black widow spider. Or the high contrast stripes on bees, wasps and skunks.But bright colors also make them more visible to predators; so how did this trait develop?Scientists looked at three coloration schemes across more than a thousand species, and found they fell into three groups:Camouflaged. Brightly colored. And Hidden-signal—which flash colors only when threatened.Their research suggests that some hidden-signal types developed chemical deterrents. Then, as generations passed, both their poison and coloration increased, spreading to other parts of the body until a brightly colored, highly venomous species emerged.Still, many species remained camouflaged, but developed strong poisons. While others evolved to mimic the dangerous coloration of their peers, but remained harmless. It can be hard to know which is which.So, if you ever see a brightly colored or a well-camouflaged wild animal, best to look but don’t touch.

True to its name, the Venus Flytrap looks like it came from another planet, and it eats bugs.It may seem alien, but carnivorous plants are surprisingly common. There are 750 species, living on every continent but Antarctica.They exist wherever the soil can’t provide all the nutrients that plants need. So they look to other sources—often insects.The Venus Flytrap is the most well-known. Its “jaws” stand open until an unsuspecting fly touches hairs within for several seconds. That triggers an electrical impulse and the jaws snap shut. Then enzymes slowly digest the prey.The Sundew has tentacles with glistening drops on the ends that look like nectar. But insects that land to partake find they’re actually sticky digestive fluid. The Sundew’s tentacles wrap around the bug and feast.The Pitcher Plant looks like its namesake, with a smell that attracts insects. But if they crawl inside, the walls are too slippery to escape.Waiting at the bottom: more digestive enzymes that will melt them alive.And if that’s not gross enough… the ‘toilet plant’ looks like its namesake. It produces a sweet nectar to lure rodents or bats.When they come to drink, extended beneath them is a bowl to catch whatever they excrete. The plant gets all its nitrogen and other minerals from animal droppings.So, if you think eating bugs is unappetizing, well, it could be worse.

As you listen to these words, you’re using energy. The radio in your car is powered by gasoline. Your EV, phone or computer runs on electricity.We rarely stop to think about the massive amounts of energy we use, 24-7-365. And we rarely think about where it comes from. But I can tell you in one word. Because all energy comes from one place: Earth.Oil, gas and coal are fossil fuels, made of ancient plants, algae and plankton, that were covered in sediment, compressed, heated and turned into hydrocarbons through time. They’re essentially solar energy converted through photosynthesis and geologic processes into … Earth resources.As long as we have a sun, sunlight is renewable. But the solar panels to collect it are rebuildable. They too are made from Earth materials—glass, silica and aluminum—then after a couple decades need to be built again, of more materials.Hydroelectric dams are powered by rainfall, from Earth’s water cycle, but built of giant volumes of concrete and steel.Drilling, mining and manufacturing, for all these energy systems, consume huge amounts of Earth materials, water and land.Even the energy that powers our bodies comes from Earth; plants of course, but also fertilizer, farm equipment, transport trucks and grocery stores that are made of, or powered by, Earth resources.We live on a generous planet that takes care of us. Let’s make sure to return the favor.

Rabies is almost 100% fatal. It can affect any warm-blooded creature and is transferred by any bodily fluid – though most commonly by a bite that passes saliva from the infected animal to the blood of another.It takes days or even months for the virus to incubate. But once active, it attacks the nervous system causing paralysis, coma and eventually death.Rabies kills 60,000 people annually worldwide, mostly in Africa and Asia. Before the 19th century, it was far more deadly, because there was no treatment.Then came Louis Pasteur. First, he invented the process to sterilize milk and other liquids, by heating them near boiling to kill bacteria.Next, he focused on diseases, beginning with cholera. He cultured it in a lab, then discovered that chickens injected with older strains weren’t affected by the disease – and were immunized against new strains.He developed a similar treatment for anthrax, which often infected livestock, then moved on to rabies.He found that the dried spinal cords of animals killed by the disease contained a weak version that could be injected to immunize against the live virus.Thanks to Pasteur, rabies has been almost completely eradicated in the US, with several organizations aiming for zero cases worldwide by 2030.Do your part by vaccinating your pets, and yourself, if bitten, or traveling to areas where rabies is still endemic.

Water bears are so hardy that researchers are studying them to try to advance human medicine.Scientifically they’re called tardigrades. There are over a thousand species living in wet environments, from the deep sea to moss beds in the Himalayas.They may look like bears, but there’s no relation. To begin, they’re microscopic, usually less than a millimeter in length.They have a digestive tract, but no bones, lungs or circulatory system. Their bodies keep their shape by holding fluid within – like a water balloon.If the tardigrade’s watery home dries up, it dries up too. It curls up in a ball, shrinks to a third its normal size, and goes into suspended animation…where it can stay for decades until there’s enough water to rehydrate.If the water freezes, the tardigrade produces proteins to protect itself from ice crystals forming inside its body. It withstands UV exposure by producing its own bioluminescence. It endures high levels of radiation with genes that regenerate cells.Qualities like these have made tardigrades successful for over 500 million years.And today, scientists hope to learn from them: how to repair human cells after cancer therapy. How to freeze then thaw organs for transplant. How to make vaccines last without refrigeration.Many big ideas may come from the tiny, nearly indestructible water bear.

Scientists studying Ponderosa pines in a Colorado forest were interrupted by a wildfire – which led them to a surprising discovery.The researchers were investigating the trees’ photosynthesis, during which they take in CO2 through pores in their needles, called stoma.When heavy smoke from the wildfire filled the forest, the scientists had their equipment in place and operating, and witnessed something unexpected: the trees held their breath. They closed their stoma, apparently to stop the smoke from entering.The scientists combed past research for something similar, and found a study from 100 years earlier, that showed coal smoke caused a different species of pine to produce a semi-permeable pitch blocking their stoma, to exclude the smoke while still allowing some CO2 to enter.In both cases, reduced CO2 meant reduced photosynthesis…which meant the trees produced less glucose.Glucose powers the growth of new wood -- and new needles to conduct more photosynthesis. So, when the trees close their stoma, it slows growth.Other scientists estimated that the trees’ growth rate during these smoky conditions fell by up to 15% -- as they traded growth for protection from smoke.Clearly, over millions of years of evolution, this has proven a successful strategy. Understanding it will help scientists better predict how forests may be shaped by wildfires in the future.