EarthDate

Forty years ago, bridge renovations in Austin, Texas attracted an unwelcome visitor – in fact over a million of them. Engineers had run support beams under the entire length of the bridge. Small slits between the beams opened into deep crevices … Just like those preferred by the Mexican freetail bat in their native habitat. Soon a huge colony lived under the bridge. And many Austin residents wanted them out. They had heard horror stories – bats spread disease! They might bite us! But Merlin

In America, we’re number one! In many things. Some are not so good. Like garbage. Each American makes 1500 pounds of it a year. Two-thirds could be recycled, but isn’t. Most goes to landfills. Who’s number one in recycling? Sweden. Just 1% of their garbage is landfilled. In the 80s, Sweden began building a circular economy for garbage. They tasked manufacturers to devise ways to handle their packaging after it was used. And they created robust consumer recycling programs and education. Now h

Have you ever wondered how squirrels find the nuts they hid months before? A typical squirrel can store 3,000 of them in a fall season, in dozens of locations. It seems almost impossible that they could remember them. But they do. There are 200 species of ground squirrel, tree squirrel and flying squirrel that rely on stored seeds and nuts. To do that, they need to return to them even after leaves fall and snow covers the ground. How do they do it? Smell plays a role. But sight and memory ar

LEDs are everywhere today. But what does L. E. D. stand for anyway? Luminous Efficiency Device? Less Electricity Demanded? Not quite – though both correctly describe Light Emitting Diodes. They make more light, from less electricity, than any other technology. Incandescent bulbs of the 20th century heat a metal filament until it glows white hot. They produce light, but much more electricity is converted into, and wasted as, heat. Fluorescent tubes pass energy through a gas that glows. They c

Rust is common on Earth. It shouldn’t exist on the moon. But somehow, it does. Rust is just the common name for iron oxide. Iron that has bonded to oxygen. The moon, however, has no oxygen. Yet lunar rovers have recovered grains of iron oxide in lunar soil. How could they have gotten there? One possibility is from Earth. Or rather, from our atmosphere. The magnetic field of our planet, called its magnetosphere, surrounds Earth like an invisible force field. The sun produces a solar wind of

Imagine there was not one species of human…but many. One stronger. One smaller. All different, but closely related. Around 40,000 years ago, that’s exactly how it was. Homo sapiens – us – shared Earth with several other Homo species. Then those other ones went extinct, and we carried on. The sole survivors. Why? Because we could better adapt to changing climates. And that’s because of a few key qualities. First, we had more flexible diets. We could eat large animals or small. Fish, fowl, or f