14 Jan 2022

The Cold Truth about Ice

You know a lot about water already because it’s such a big part of your life! Ice is what we call water when becomes a solid, and it’s a really important part of life on Earth. 

Three truths everyone knows about solid ice water

  • it solidifies at 0°C, and is the basis for the temperature scale 
  • its solid floats just above its liquid, with 90% below the surface 
  • it expands as it solidifies, unlike most every other substance
The water in this drink burst the can when it solidified.
The water in this drink burst the can when it solidified.

Seven things you know about water but may not have thought about 

  • water colder than 0°C continues to run as liquid in rivers 
  • ice is bendable 
  • ice can be clear or opaque 
  • salt lowers the freezing temperature, that’s why salt melts ice, but the salty oceans still form sea ice! 
  • the calorie and joule measures are also based on water’s properties 
  • ice takes the shape of its container, but 18 different shapes can be found inside that ice —most often, ice particles are shaped in hexagons
  • ice can make shapes like feathers, sheets, columns, caps, bergs, balls (like hail), snowflakes, and many more!


Ten totally cool things about solid water

  • ice can form straight from gas, without going through the liquid phase—snowflakes can form this way 
  • water can stay liquid below freezing, especially if it’s under pressure, moving, has air blown through it by a “bubbler” near boats, or even if it’s very still 
  • “supercooled” liquid water will freeze right before your eyes with the slightest vibration

  • the salt in sea ice collects in pockets that melt and drain, so the salt content of sea ice is much lower than the water it came from 
  • ice reflects 90% of the sunlight and can give you a sunburn in winter!
  • the oldest ice on Earth today (under the Antarctica ice sheet) is about one million years old! That’s about 12 500 human lifetimes, or 40 000 polar bear lifetimes! 
  • ice traps air when it forms, so by examining old ice, scientists can learn things about the old air and other climate details 
  • ice can get thick enough to drive on, and some towns way up north use ice roads to drive goods to their stores 
  • one of the oldest sailing clubs in Canada actually started as an ice-boating club! 
  • ice was harvested from lakes and rivers in winter for use all year until the late 1800s—it’s still harvested today to make sculptures


One lie about ice

Dry ice isn't ice at all. It's made from frozen carbon dioxide (that's CO2, like you breathe out), not water! And breathing in too much of it can be deadly.


Try It Yourself! Become an Ice Bender 

Next time there's a thin layer of ice on a pond or lake, skim a small rock out onto the surface. Keep skimming rocks out until the weight of them starts to bend the ice down, but not break it. How much will it bend? Don't walk on that ice!

The Boreal Forest wins an award!

Terrific news about our own L.E. Carmichael! A fine book by this author and her illustrator Josée Bisaillon has won a national award.

Kids Can Press is the publisher of their book, The Boreal Forest: A Year in the World's Largest Land Biome.

 


The word went out on Twitter from Kids Can Press, saying:

THE BOREAL FOREST by @LE_Carmichael & illustrated by @joseebis

has won the 2021 Children’s Literature Roundtables of Canada’s Information Book Award!

 

Read all about the Information Book Award, and Children's Literature Roundtables of Canada at this link. It's hard to go wrong, reading any of the books on the award's shortlist!


7 Jan 2022

Finding Hidden Treasures in the Cedar Swamp

by Nina Munteanu


It was early winter, before the snows, as I entered the large cedar swamp-forest and felt magic touch my shoulder.

It wasn’t just the deep soggy forest and the twittering birds or the fresh pungent smell of cedar in the air. Or the lanky trees creaking in the warm wind. There was something in the air that stirred my senses. The magic of discovery.

Amid the soft hush of the breeze through the leaves, the tall trees leaned into each other, groaning and clanking like whispering gossips. Moss crept up their widely planted feet. It carpeted the russet duff on the ground with splashes of fluorescent green. Several over two-hundred-year old cedars had fallen and their decaying bodies were feeding a whole new generation of trees. Cedars growing on cedars. I left the path and climbed onto a several metre-wide and twenty-metre long moss-covered cedar corpse. My steps sprang over spongy ground—now a mixture of rich soil, decaying wood, fungus and detritus. I could make out the black fibrous layers of decaying wood beneath a carpet of moss and dead leaves.
 

I’ve been told that the heartwood of eastern white cedar (Thuja occidentalis) is highly resistant to moisture, decay and insect infestation due to the phytoncides (oils and acids) it produces; it’s these compounds that give off its distinctive pleasant and calming aroma. Many of the compounds are variants of thujone and include alpha pinene, alpha thujone, beta thujone, bornyl acetate, camphene, camphone, delta sabinene, fenchone and terpinenol.

A fallen cedar can remain intact, slowly decomposing on the forest floor for over a century. This is due to its natural preservative that is toxic to decay-causing fungi. Nursery logs provide rich habitat for seedlings to take root and a complexity of growing plants, fungi, liverworts, and other wildlife to thrive in. These ancient trees play a vital role in climate balance. They store two to three times more carbon than second-growth trees. Because of their slow decay, cedars lock carbon in their biomass for a longer period—creating a slow and efficient carbon store. Even dead snags and nursery logs continue to store carbon as they provide habitat for other living things.

Simply walking in a cedar forest can directly boost your health by breathing in its aerosols: cedar oils (terpenes) help boost our immune systems; cedars have anti-oxidant compounds and anti-inflammatory compounds. You also help your well-being by listening to the forest’s curative infrasounds and other frequencies; they help to quiet your mind. The benefits are numerous: from heightened calmness, creativity and problem solving, greater immunity, to a greater sense of general well-being and overall happiness. When you spend time in the forest, you inhale beneficial bacteria, plant-based essential oils, and negatively charged ions.

The eastern white cedar also contains high amounts of vitamin C (50 mg of vitamin C per 100 grams). Because of this, various parts of the tree (mostly leaves and bark) are used in herbal medicine, mainly for their immune-system stimulating effects. When 16th century explorer Jacques Cartier and his men fell ill with scurvy, the native people helped treat them with a tea from this conifer. The tea is made by dropping several small pieces of cedar leaves into water that has just been boiled and allowed to steep for five to seven minutes then strained into a fresh menthol-aromatic tea.

Curious to taste cedar tea, I convinced good friend Merridy to accompany me on my next excursion to my magic cedar swamp forest in the Trent Nature Sanctuary near Peterborough, Ontario. We collected some fresh leaves from a fairly-young tree then upon returning to Merridy’s place, we boiled some water and cut up the cedar leaves, which gave off a refreshing citrus camphor smell. I dropped the fresh leaves into the pot of boiled water and let it steep for seven minutes then poured the light-coloured tea into two cups. The tea was hardly more than water. There was just the hint of colour, no more. I inhaled the tea and took in a very mild scent of cedar. More like a woodsy smell.


Then we took our first sips. We shared our first impressions: “Tastes like cedar,” said Merridy unceremoniously and gave a short laugh. Then she added, “It has a mild delicate taste.” I was pleasantly surprised at the gentleness of the flavour. The first sip took in subtle notes of the forest with an aftertaste of cedar. The second larger sip yielded more robust citrusy and astringent notes of cedar bark and wood. I could detect the sharper complexity of terpines. It was fresh like a forest breeze in springtime. In short, it was delightful.

Despite its beneficial properties, cedar tea should not be taken in excess. One of the reasons is thujone, a volatile monoterpene ketone with a menthol odour, best known as the chemical compound in the spirit absinthe. The eastern white cedar contains an appreciable amount of thujone (hence the tree’s genus name Thuja). This monoterpene can be toxic to brain, kidney, and liver cells and can cause convulsions if taken in too high a dose. Given its interference with certain neuro-receptors, small doses of thujone may convey stimulating mood-elevating effects. The lesson here is that if you drink cedar tea, do so in moderation. Enjoy its beneficial qualities, but respect its other qualities!


A Puffball Treasure
Back in the cedar swamp forest, I was crawling on the spongy ground, clutching my camera to take some close shots of the bright moss that was fruiting in profusion. Before I knew it, I’d stumbled into the dip between two giant decayed logs. There, like Indiana Jones in the deep jungles of Borneo, I discovered my hidden gold: puffballs!

Dozens of them littered the ground, looking like eggs, as though some puffball-hen had laid them. Whitish, round and with a paper-like texture, each plump spore sac pouted with a beaked mouth (peristome) and sat nested in a star-like “collar” (exoperidium) with decorative cracks and fissures. The puffballs resembled a chorus of singers “oohing”. I identified the puffball as a Collared Earthstar (Gaestrum triplex), a saprobic fungus that commonly grows in humus-rich deciduous/coniferous forests amid leaf litter. The puffballs release their spores when the wind blows past the pointed “mouths” or when they are disturbed by rain or animals—like me. Reverting to a childhood inclination, I poked one with my finger and it released a yellowish-green cloud of spores. I clapped my hands with glee and realized that I’d just opened a door to magic.

 


Then it started to rain. First a light rain that sizzled over the ground and vegetation. Then drumming. And finally pelting. I inhaled the freshness in the air and didn’t mind that I would soon be soaked—my raincoat wasn’t really a raincoat, more like a cheap wannabe. I didn’t mind because the magic was transforming and I was part of it.

With the rain, the greens and russets grew intense. The moss sparkled. The air grew thick with moisture and a mist veiled the forest in soft gossamer. When I looked down at my puffballs, I noticed that the delicate whitish rice-paper spore sacs had transformed into tan-coloured rubber balls that sprang back like pressurized balloons if poked. I would never have imagined this and found myself grinning in the magic of discovery.

 Just as I made to leave this magical cedar swamp forest, I caught sight of what looked like an errant wandering puffball on top of one of the ancient logs. Unlike the others whose spore sacs were nestled in an outer collar, this puffball’s spore sac was perched proudly high, atop a series of ‘legs,’ the rays of the outer peridium. The puffball resembled an octopus standing on its many tentacles. I later identified it as another species of Earthstar, the Beaked Earthstar (Geastrum pectinatum), which likes to live under (and on) conifers.

The puffball looked like it was going on walkabout. Perhaps I would join it.

31 Dec 2021

Fungal Fabric

by Kim Woolcock

The new year makes me think of new beginnings. Why not new bio-inspired technologies?
 

As microplastics clog up our newsfeeds and the biosphere, the search for biodegradable materials becomes more important. One that’s catching my attention is fungal fabric.

Mycena inclinata, Clustered bonnet
Image credit: Stu's Images

When many people think of fungi, they think of mushrooms or mold. Fungi are both of these things, but they are also so much more. The mushrooms that we see popping up in the rainy spring and fall are fruiting bodies, made to distribute spores. They are just the tip of the underground iceberg. Made of tightly intertwined fungal threads called hyphae, they are produced by huge webs of hyphae living invisibly in the soil, in rotting wood, in plant roots and leaves. These hyphae live inside their food, producing enzymes that degrade it, and then soaking up the released nutrients.

 

Oyster mushroom (Pleurotus ostreatus) mycelium growing on coffee grounds in a petri
dish
Image credit: Tobi Kellner


Hyphae can grow to form any shape (just look at the many shapes of mushrooms, from corals to cup fungi to tooth fungi), and dried mushrooms have a tough and rubbery texture. Innovators are leveraging this combination of traits to produce a wide variety of fungal fabrics. The hyphae are like the threads of cloth, interweaving as they grow. This fabric weaves itself!

Starting with waste products like sawdust or grain husks, designers add fungal spores, a small amount of water, and wait for the fungus to devour the food and fill the mold. Fungi grow quickly, so fungal leather can be produced in a matter of weeks. The resulting mat of hyphae can be dried, tanned, and dyed to produce “leather” that is strong, durable, breathable – and beautiful.

Designers are using fungal leather to make watches, purses, clothing, and shoes. Maybe some fashion-forward fungal leather items are just what my new year needs.

 

17 Dec 2021

Netta Englehardt: The Woman Escaping the Black Hole Paradox

 

Netta Englehardt is a 32-year-old theoretical physicist. She’s a professor at MIT and is making waves for her work in resolving a decades old paradox, relating to Black Holes and Quantum Mechanics. In the 1970s Stephen Hawking came up with the Black Hole Information Paradox, and physicists have been working since then to make sense of the problem.

Hawking found that Black Holes don’t continue gobbling up matter forever. Black Holes have a temperature; large ones are very cold, but small ones a little warmer, and they all radiate energy. Eventually they totally evaporate and disappear. Just to be clear, big Black Holes can be 1/10-14 degree Kelvin (almost absolute zero), and one the size of a Coronavirus would be room temperature. And eventually is a long time – many billions of years, so don’t hold your breath. None of this is paradoxical.

The paradox comes because Hawking’s calculations showed that matter evaporating from a Black Hole has lost the information about the matter that went into the Black Hole. That’s a problem for Quantum Mechanics, which holds that all processes must be reversible. A little hard to understand because it’s not intuitive to us, living in a world where we can’t perceive quantum scale events. But it’s a fundamental principle of quantum mechanics, called Unitarity. If all the information about the Black Hole matter has disappeared when the Black Hole has fully evaporated, then it’s not possible for the process to be reversed.

For over forty years physicists have been looking for an error in Hawking’s equations, trying to find another equation which shows that the information is not lost. The focus of all of this is on calculating the entropy of the Black Hole. As the Black Hole swallows particles, the information about those is particles is lost to the world outside of the Black Hole, and the entropy of the Black Hole increases. Hawking’s equations showed entropy continuing to increase as the Black Hole evaporates. That’s the paradox. To preserve Unitarity, the entropy has to decrease as the Black Hole evaporates. 

Englehardt aged 26 delivering a graduate lecture

The world of theoretical physics is very excited because Englehardt and her collaborators have found a different way of measuring the entropy of the Black Hole, and this measurement shows exactly what is needed – entropy increases as the size of the Black Hole increases, and then decreases as it evaporates. How do they do it? It’s so far beyond my understanding that I won’t pretend to be able to explain it, but it has something to do with the area of the event horizon. That’s the boundary beyond which a particle gets sucked into the Black Hole. And it involves an “extremal surface” where space-time is bent enormously by the forces of gravity in the incredibly dense Black Hole.

There’s a wonderful symmetry to Englehardt being a crucial contributor to solving Hawking’s paradox. Englehardt’s family emigrated from Jerusalem to Boston, when she was nine. “As a child, I loved reading,” she says. “But I didn’t speak any English. When we moved to the US, we had only taken a handful of Hebrew-language books with us. So I read everything in the house, until there was just the one last book left. It was ‘A Brief History of Time’ by Stephen Hawking”. And the rest was history. 

The Breakthrough Prize Foundation awarded Engelhardt the 2021 New Horizons in Physics Prize, an award of $100,000 that recognizes promising junior researchers who have produced important work in their field.