For the Love of Frogs

by Yolanda Ridge

For the Love of Frogs

 

This week, I finally visited what people in my town affectionately (and not-so-creatively) refer to as “the frog pond.” Being at home during the pandemic, I’ve sort of lost track of time. Maybe that’s why I expected the tadpoles to be bigger. Or maybe that’s why I was surprised—like I always am—to see so many of them huddled together, totally unconcerned about “social distancing.”

Over the next month, my sons and I will visit the pond regularly to see them grow. There’s nothing quite like watching a pond swarming with small, simple creatures transform into a community of frogs. Perhaps I will be lucky enough to have good photos to share in my next post. In the meantime, here are ten cool facts about frogs:

1. There are over 5000 different species of frogs, including the “flying frog” that leaps from tree to tree with help from the webbing between their toes.

2. Frogs come in many different colours, even black and white.

3. A frog sheds its skin about once a week. Instead of letting the dead skin go to waste, they eat it.

4. Many frogs can jump over 20 times their height. If a human could do that, they’d be able to leap-frog over a 100-foot building!

5. Rumour has it that some frogs, including African Bullfrogs and Horned Frogs have really smelly farts.

6. Some frogs are as small as 7.7 mm (the size of a dime). Others, like the appropriately named “goliath frog” are as big as 32 cm (the length a school binder).

7. Frogs don’t drink water like we do, they absorb it through their skin.

8. Frogs eat with their eyes. Really. In order to swallow their food, they blink to push their eyeballs down on top of it.

9. The most poisonous animal on earth is the “poison dart frog” The Golden Poison Dart Frog can have enough toxin in its body to kill a human.

10. Pollution and climate change are a huge threat to frogs. They’re considered an “indicator species” because their health tells scientists a lot about the health of the planet.

BONUS FACT: A person who studies frogs is called a herpetologist (which sounds a lot like “burp”-a-tologist to me).

Is there a frog pond near your house? Or a small bit of water with a frog living in it? Now that summer’s finally here, I hope you get a chance to check it out!

Yolanda Ridge is a middle grade author and science writer from Rossland, BC. Visit her website at www.yolandaridge.com to find out more.

Photo credits:

Tadpoles by Yolanda Ridge

Milk Frog by Da Vinci Science Center @Flickr

Poison Dart Frog by Da Vinci Science Center @Flickr

Science, Traditional Knowledge, and Beautiful Picture books

Science, Traditional Knowledge, and Beautiful Picture Books

by Gillian O'Reilly

Celebrate National Aboriginal Day (June21, 2020) and science by exploring these beautiful picture books.

For toddlers and pre-schoolers, Indigenous artist Roy Henry Vickers and his co-author Robert Budd have created gorgeous board books One Eagle Soaring and Sockeye Silver, Saltchuck Blue (Harbour Publishing). Here's a link to the listing for One Eagle Soaring at Harbour Publishing.

These books introduce little ones to numbers and colours and the landscape, flora and fauna of the Pacific Northwest. Just out this month is the next book in the series Raven Squawk, Orca Squeak, looking at -- you guessed it -- the sounds animals make. Click here for a link to learn more about this book.

For slightly older children, we turn from animals to plants with A Day with Yayah (Tradewind Books), written by Nicola I. Campbell and illustrated by Julie Flett, both award-winning creators. In BC’s Nicola Valley, a grandmother (Yayah) shares her extensive knowledge of the natural world with her grandchildren, and encourages them to use the Nłeʔkepmxcin words for the plants they are collecting. Here's a link to find this book at Tradewind.

Two more excellent depictions of traditional knowledge being shared through generations can be found in A Walk on the Tundra and A Walk on the Shore. (Here's a link to where these books were discussed in a previous blog post on Sci/Why along with other books from publisher Inhabit Media).

Enjoy these books on National Aboriginal Day and all year around. Happy reading!

Gillian O’Reilly is the former editor of Canadian Children’s Book News and the co-author (with Cora Lee) of The Great Number Rumble: A Story of Math in Surprising Places.

Book Awards for Helaine Becker!

One of our own authors on Sci/Why blog, Helaine Becker, announced today (June 16) on Facebook good news about two of her books. She reports:

Forest of Reading awards are being given out today. Thrilled that SLOTH AT THE ZOOM was chosen as a Blue Spruce Honour Book, and COUNTING ON KATHERINE as a Silver Birch Express Honour Book. Thanks , OLA!!!

Glad to hear the Ontario Library Association moved their Forest of Reading awards to an online event, when the pandemic made it impossible to gather in person to celebrate these and other fine books. Ask at your library and local bookstore for books on science and more by Canadian author Helaine Becker.

Congratulations, Helaine!

Online STEM Fair

Science Fairs are such exciting events! But during the pandemic, it's not good to plan large gatherings where people will come in close contact. Here's a link to an online science fair for students across Canada from grades 7 through 12 or in Quebec's Cégeps. The Make: Projects website has a detailed virtual display of the Online STEM Fair 2020 sponsored by Youth Science Canada/Sciences Jeunesse Canada and several corporate donors.

The topics for these student projects are many and various, from agriculture & fisheries to environment & climate change, including digital technology and health and much more. If you're thinking of your own projects (past or future), take time to look at some of these award-winning projects at https://makeprojects.com/ysc/home

And if you're finding this link in the future when a new post is at the homepage for makeprojects.com you can look for Online STEM Fair in their website's search window.

Squirrels, Cats, NASA - Connecting the Dots

The genesis of this blog was this Youtube video by Mark Rober:
https://www.youtube.com/watch?v=hFZFjoX2cGg

The video shows squirrels brilliantly conquering a diabolically difficult obstacle course to get at a delicious treat. If you’re not one of those who’ve seen it (22.5 million in the first week, late in May) don’t miss it. Around the 16 minute mark he (Mark) demonstrates the launch platform in slow motion. It turns out that squirrels are amazing at figuring out where and how they’ll land when flying through the air. 

Just like cats! And Mark mentions cats’ ability to land on their feet when dropped upside down. He also discusses briefly the physics behind this ability. Angular momentum (or Moment of Inertia) plays a part. Cats and squirrels control their rate of spinning by extending or pulling in their legs. Figure skaters do this as well. Pulling your arms in makes you spin faster; extending your arms slows your spin. Of course, figure skaters have to keep at least one foot on the ice. Here’s an illustration of that from my book Faster, Higher, Smarter.

 

Squirrels and cats flying through the air have four appendages to use to control their angular momentum. 

 

But that’s not the whole story. Figuring out how cats can turn over in a split second to get their feet under them took scientists nearly three hundred years. 

First up was Antoine Parent, a French mathematician best known for a three volume treatise on Analytical Geometry in 1700. He explained (incorrectly) that the upside down cat (A below) hollows its back, moving its centre of gravity above its axis (B); this makes it unstable, causing the cat to rotate to the feet down position (C). The explanation doesn’t work because there’s nothing supporting either end of the cat, so there’s nothing to make it rotate. 

 

Many other scientists studied the cat problem. Probably the most famous was James Clerk Maxwell, who formulated the laws of electro-magnetism, unifying electricity, magnetism and light. Maxwell developed a reputation while at Cambridge in the 1830s for throwing cats out of windows. (He denied this, saying that he only dropped cats onto a table or bed, from a height of inches). No-one came up with any good explanations. Many suggested that the cats “cheated” by pushing off against the hands that were dropping them. The difficulty for scientists in solving the problem was that cats right themselves faster than the human eye can follow. 

A breakthrough came in 1894. Etienne-Jules Marey, a French scientist, made brilliant use of the new technology of chronophotography. He took a series of pictures at 12 frames/second, of a cat turning over in the air. Marey was inspired by the work of Edward Muybridge, who famously took a series of pictures of horses in motion, settling an age-old debate about whether all four hooves are ever off the ground. (They are).

The images start at the right and move to the left.

But even this wasn’t quite enough to solve the problem. It showed clearly enough that the cat wasn’t pushing off against the hands dropping it. Marey gave an almost correct explanation of the cat changing its angular momentum first by pulling in its front paws and extending its back legs to give it more intertia at the back, and allowing it to turn its front half more; and reversing the procudure to allow the back half to 'catch up'. But this still doesn't explain how the cat starts out with no angular momentum but can still rotate. There were also suggestions that the cat achieved that by rotating its tail. The tail rotation theory, though, didn’t explain how tailless Manx cats can also fall feet down. 

The solution had to wait for NASA-funded scientists Kane and Scher. In 1969 they published "A dynamical explanation of the falling cat phenomenon". The key to their model is the exceptional flexibility of the cat's spine. The cat bends to approximate two cylinders (chest and lower body) at right angles to each other. The total angular momentum of each of the “cylinders” and the overall connected body remains zero as the cat twists around to place its legs below it. 

Why did NASA fund the study? Because it needed to develop strategies for astronauts floating in space to orient themselves. It worked! Thanks, kitty. 

Astronaut Bruce McCandless on First-ever Untethered Spacewalk