Something’s happening high in the mountains, invisible to humans—that can dramatically affect our water supply.

It’s a process called sublimation, where a substance goes from its solid form directly to a gas, skipping the liquid state altogether. And water is one of the few substances on Earth that can do this.

It takes 80 calories of energy to melt a gram of ice into liquid water. Then another 540 calories to boil it into gas. But when the environment provides those 620 combined calories all at once, ice can go straight to vapor.

And high mountains are the perfect environment for this to occur, where glaciers and snowpack, exposed to bright sunlight and blown over by warm, dry winds, will often vaporize directly into the atmosphere.

The ice is literally blowing away.

This is important because glaciers and snowpack are nature’s water towers. We depend on their meltwater to fill rivers and our reservoirs, where we use it for municipal water, agriculture and industry.

To calculate the water available to us, scientists analyze the volume stored in the mountains. But sublimation is very difficult to predict, making our water supply hard to measure.

It’s a seemingly simple problem that, especially in places like the American West, impacts millions of lives.

Yet another example of where better data and advancing technology could have a very practical application.

When is a potato not a potato? When it’s a sweet potato!

And when is a sweet potato not a sweet potato? When it’s a yam!

What I mean is, these three food staples may look similar, but they’re not related at all.

The potato is part of the nightshade family; it’s actually kin to tomatoes, eggplant and tobacco.

It comes originally from the Andes, where the Incas domesticated potatoes many centuries ago. In Peru, there are still more than 4,000 varieties!

Potatoes went to Europe with Spanish sailors in the 16th century, who realized their vitamin C prevented scurvy. Then they made their way to North America and around the world.

Today the potato is the fourth-largest food crop, behind maize, rice and wheat, with China and India the biggest producers.

The sweet potato, meanwhile, came from the tropics in Central America and the Caribbean, from a vine related to the morning glory flower …

While the yam comes from the lily family. Different species were domesticated in different places, perhaps as early as 10,000 years ago in Africa.

West African slaves brought the culture of cooking yams to the Americas, but unable to find the real deal, they substituted sweet potatoes and called them yams, and the naming mash-up began.

No matter. All three of these tubers are good sources of complex carbohydrates, dietary fiber, vitamins and minerals, so you might as well eat them all!

Lithium-ion batteries have transformed our lives. They make our smartphones possible. They power our laptops and most other rechargeable devices—including, increasingly, our vehicles.

We’re even hoping to put giant batteries on the grid, to store solar- and wind-generated electricity when it’s being produced to use later when it’s not.

With that increased demand, lithium has become expensive. Its supply is volatile and controlled by just a few countries.

So, battery scientists are looking for an alternative. And they may have found it—in sodium. It’s a light metal related to lithium and is globally abundant and cheap, just 2% the cost of lithium.

And it can be used in similar ways—with advantages and disadvantages.

Sodium-ion batteries maintain most of their performance in cold temperatures, where lithium suffers.

They’re less prone to runaway thermal reactions, meaning fewer fires. And may be easier to recycle.

However, their energy density is lower than lithium and their lifespan is shorter, while their size and weight are greater.

This may make sodium batteries best suited for the grid. But scientists are working to improve them and hybridize sodium with lithium to leverage the strengths of both.

Combined designs could be smaller, longer lasting, safer, hardier and cheaper. Only time will tell if they could scale up enough to transform our electrical systems … again.

It might surprise you to know that plants can hear, and even speak, in their own unique ways.

Scientists have discovered that some plants respond to the sound of water.

They found that the roots of common garden peas will actively grow toward vibrations made by running water—even if it’s within a pipe and unreachable by them.

In related tests, they played recordings of the wingbeats of bees and moths to several species of flowers. The flowers responded within three minutes by producing more nectar to draw in the pollinating insects.

Conversely, new studies have shown that plants emit sounds when they’re under stress and/or damaged: sort of like the plants are crying.

When stressed by drought, or cut by researchers, several unrelated species of food crops emitted chirps, up to 35 times per hour. These noises were ultrasonic, much too high for human ears, but picked up by scientific microphones.

When brought down in pitch to be intelligible by us, they sound like bubble wrap popping. The scientists surmised it comes from air bubbles expanding and bursting in the plant’s vascular system.

The researchers then used this data to create a machine learning algorithm and were able to listen to other plants and successfully determine what stresses they were under.

In the future, this could lead to acoustic crop monitoring—which could give plants the water they’re crying out for.

There’s a spooky, otherworldly intelligence on Earth—and it’s called the slime mold! That may sound like a horror movie, but it’s real.

And it grows in leaf litter … perhaps in the woods behind your house, waiting for darkness to creep under your door …

Ok, not that last part. But slime molds can creep and carry out many complex behaviors—all without a brain!

Slime molds aren’t really a mold at all, but a strange mix of animal and fungal characteristics. And they’ve been around for 600 million years. Today, their 900 species separate into two types: plasmodial and cellular slime molds.

The plasmodium begins as a single-celled organism, then starts to divide its nucleus but doesn’t divide cells. The result is sometimes thousands of nuclei living within one huge cell membrane …

Which can grow to several feet across, slither around, grow feet and navigate a maze. It can find food and remember where it found it. It can spread itself into networks, like tree branches or veins, that mimic the most efficiently planned road networks.

Cellular slime molds are multicellular creatures that can shape themselves into sluglike forms and creep across the ground.

When conditions are right, both types can sprout fruiting bodies, similar to mushrooms, which release spores and grow into new slime molds.

Try that on for a Halloween costume!

For centuries, humans have relied on pigments to color our products. But a new discovery may change that.

Pigments produce color, ironically, by absorbing light. Chlorophyll, for example, absorbs all colors of the light spectrum except green, which reflects off leaves, making them appear green to our eyes.

Pigments and paints that we manufacture work the same way.

But a few years ago, scientists working to create a perfect mirror out of aluminum noticed that microscopic particles of aluminum oxide clumped on its surface to form dark clouds.

Upon closer inspection, they realized they had created structural color in the oxides.

Structural color can be found in butterfly wings and some feathers, where extremely tiny, even nanoscopic particles determine which wavelengths of light, which colors, reflect back to our eye.

The scientists began experimenting, and by adjusting their process, could produce a multitude of colors.

Their structural-color paint is incredibly lightweight, and the coating incredibly thin.

A few pounds could cover an entire passenger jet—compared to more than a thousand pounds of conventional pigmented paint—saving energy every flight.

What’s more, structural-color paint reflects rather than absorbs heat, which could save huge amounts of energy in cooling and heating.

It’s not commercial yet, but if and when that happens, it could change the way we look at color.

99% of Earth’s biomass is estimated to be on land, with only 1% in the oceans.

However, Earth’s biomass is mostly plants. And the average terrestrial plant is huge—a 2-ton tree that could live for a century. Whereas the average marine plant is tiny—a single-celled organism that might live just a few weeks.

That said, about three-quarters of animals, by biomass, live in the sea. That’s because the oceans are incredibly rich with tiny shrimp-like creatures. Antarctic krill alone make up almost 400 million tons of biomass.

But what’s really amazing about life in the ocean is how much we don’t know.

Scientists recently estimated that there are almost 9 million species of plants and animals on Earth. About 2.2 million of those are in the oceans—but only 10% of those are cataloged.

That’s right: by these recent estimates, over 90% of ocean species are unknown to science.

This correlates well with seafloor samples brought up from the deep. In them, about 90% of the species we find were previously unknown.

That may be about to change. The UN has declared the 2020s the Decade of Ocean Science. There are many projects underway to catalog species and map the ocean floor.

But with 2 million species yet to discover, it could take a thousand years to catalog them all …

Which makes it a very exciting new frontier for scientists.

The largest mountain in our solar system is not on Earth but on Mars. Olympus Mons is 72,000 feet tall—that’s two and a half times higher than Everest!

And mountains on Earth will never get that tall. Why?

First, we have stronger gravity. About two and a half times that of Mars.

Our mountains form when tectonic plates push together. One plate slides over the other, or the plates crush together in the middle. Both lift material upward.

And they form when volcanoes carry magma from within the Earth, up and out.

And as soon as they form, gravity starts pulling them back down into Earth’s crust. As they sink, their bases can melt, spreading them wider rather than tall.

Another height-limiting factor is erosion by Earth’s plentiful water.

Rain runs down a mountain, which erodes it grain by grain.

Snow freezes into glaciers, which can carve through mountain ranges, pushing rock debris downhill in front of them.

Or, water seeps into cracks and freezes, then breaks off rock in chips or entire slabs—and gravity takes over from there.

Combined, plate tectonics, gravity and water put a limit on Earth’s mountains. The top ten average around 28,000 feet tall.

However, these forces also make Earth’s mountains rise and fall faster than on other planets in the solar system. They may not be as tall, but in my view, their complex stories make them even more interesting.

Around 300 million years ago, something magnificent happened: evolution hatched the egg.

Specifically, the shelled egg. Most eggs then, and many still today, were gelatinous and could only survive in water. Like those of frogs or fish.

But the shelled egg that could contain water and nutrients and be viable on land allowed some species to move out of the water and populate the land.

Early shelled eggs were leathery, pliable and soft, like those still found in turtle and crocodile species. These rarely survive in the fossil record.

Later, eggs developed hard shells that preserve somewhat better—though not well, since their calcium compounds dissolve in acidic soils.

Still, enough were preserved for us to know that the first hard-shelled eggs came around 200 million years ago, at first for dinosaurs, then for birds, and more recently on breakfast tables.

That’s because with all their benefits, eggs had a weakness: they’re a nutrient package just waiting for a hungry predator. Some nutritionists call them the perfect food.

So most mammals developed the capacity for live birth to protect offspring longer. Even some reptiles are developing this capacity today.

If all this egg talk has you pondering the old question, Which came first, the chicken or the egg? ... the paleontologist would answer that the chicken-type egg preceded the very first chicken-like bird by 130 million years.

Leaves naturally turn yellow in the fall, when green chlorophyll fades to reveal the golden pigments already in them.

But it takes energy to turn leaves red, and not all trees can do it. Why?

Scientists have three hypotheses:

The first is sunblock. Red pigments protect the leaves better than yellow, allowing them to stay on branches longer, so that trees can harvest more nutrients before they fall.

The second has to do with insects. In autumn, aphids feed on tree leaves.

Researchers found that aphids are five times more attracted to yellow than red, so the red pigments may keep aphids away.

The third is related—but geologic. More than a hundred tree species produce red leaves in North America and East Asia, but only a few do in Europe.

During the last glacial advance, as ice descended southward, trees and animals had to migrate ahead to survive.

In America and Asia, with no east–west mountain ranges to block them, trees migrated easily—but so did their insect pests, encouraging the trees to produce red leaves.

In Europe, east–west mountain ranges blocked tree and insect migration, causing both to go extinct locally. Without those pests, most trees that repopulated those regions didn’t develop red pigments.

The real reason may be a combination, or something else entirely—a reminder that science is a process, not an outcome, and there is much left to discover.