Friday, February 27, 2015

The Eyes Have It

A couple books show how animals see the world...

Animal Eyes
by Mary Holland
32 pages; ages 4-8
Arbordale Publishing, 2015

Eyes come in different sizes, shapes, and colors. We depend on our eyes to find things, to recognize friends, to read a story. Animals depend on their eyes to find food, recognize their families, and understand the world around them.
Filled with photos, Mary Holland shows a diversity of animal eyes. She shows the difference between predator eyes and prey eyes. She discusses simple eyes and compound eyes. Her photos include night eyes and day eyes, eyes with special eyelids, and animals with more than two eyes.

Back matter includes fun facts and a matching game.

Eye to Eye: How Animals See The World
by Steve Jenkins
32 pages; ages 6-9
Houghton Mifflin Harcourt, 2014

Jenkins reinforces the message that we rely on vision to understand the world around us. Most animals do – but what they see may be different than what we see. Between the covers of his book, Jenkins introduces you to animals with more than 100 eyeballs and animals with eyes on the tips of their toes. You discover that some animals can look in two directions at the same time, and meet one creature with eyes the size of a basketball.

Jenkins uses realistic cut-and-torn–paper images to show blue eyes, orange eyes, black eyes and gold, eyes on stalks and tops of heads, eyes that see barest shadows and eyes that can see a rabbit from two miles away. At the back there’s a handy explanation on how eyes evolved, and some cool facts about each animal mentioned – plus a glossary.

Bees see the world in a totally different way than we do. Not only do they have compound eyes, but they see in the ultraviolet spectrum.   You can watch a video about how bees can see the invisible world here.

Today is STEM Friday - head over to the STEM Friday blog to see what other bloggers are talking about. Review copies provided by publisher.

Friday, February 20, 2015

The Frogs of Winter

Some critters, when it turns cold, burrow beneath the soil to stay warm. But frogs don't have claws, so they make do with scuffling under a pile of leaves. Leaf piles do help insulate you from the cold, but they don't keep these frogs from freezing.

That's OK, though, because some of these frogs -wood frog, Cope's gray tree frog, eastern gray tree frog, spring peepers, and western chorus frog - can survive freezing. When things warm up, they thaw out and hop away.

Frogcicles. Cool. But a bit more complicated than just turning into a block of ice. There's a process involved to protect the frog. Once ice starts to form in the skin, the wood frog's liver starts converting stored sugars into glucose. That glucose is carried through the bloodstream to tissues where it helps keep cells from completely dehydrating and shrinking.

Over winter, as much as 70 percent of the water in a frog's body can be frozen. One ecologist says that if you opened up a frozen frog its organs would look like "beef jerky" and the frozen water around the organs would resemble a "snow cone".

What starts this freezing process? According to the scientists in this video, all it takes is exposure to ice crystals. They stay in their frogcicle state until the snow melts - which, for frogs in the northeast, could be a long time coming.

Today is STEM Friday - head over to the STEM Friday blog to see what other bloggers are talking about.  

Wednesday, February 18, 2015

Indoor Field Trip

Taking a break from "Wordless Wednesday" for a week because of this little guy. What is it? And what was he doing hiding in the insect field guide?

See those long pincers on the front of its body? They look just like the pincers on a scorpion, don't they. But this guy isn't a scorpion - it has no stinger. It's a "pseudoscorpion", also known as a "false scorpion" or "book scorpion".  It is related to scorpions, mites, ticks and spiders. Pseudoscorpions are very small, measuring less than 5 mm long - like this one that is sitting on a piece of lined notebook paper.

In the wild, pseudoscorpions live under leaf litter and mulch, in moss, under stones, and beneath tree bark. But in the winter they can find their way indoors and into a cozy home on a bookshelf. They don't have a stinger, and won't hurt people. But they are very dangerous to the small insects and mites they hunt in your house.

If you're still snowed in, go on an indoor field trip around your house this week. Windowsills are a great place to check for ladybugs, flies, and moths - most of them will probably be dried out. Check your books, too. You might find a pseudoscorpion waving his tiny pincers!

Friday, February 13, 2015

Nikola Tesla ~ Electrical Wizard

Electrical Wizard: How Nikola Tesla Lit up the World
by Elizabeth Rusch; illus by Oliver Dominguez
40 pages; ages 7-10
Candlewick Press, 2013

"The night of Nikola Tesla's birth, lightening zapped, crackled, and flashed overhead." A pretty fitting beginning for the life of a kid who wanted to harness the power of Niagara Falls and turn it to electricity.

As a young man, when electricity was generated by direct current, Tesla wanted to figure out how to use alternating current to run motors. When he figured out how, he traveled to America to meet with Edison.

"Nonsense," said Edison. People liked their direct current; why change something that's not broken? So Tesla set out to show that alternating current would work, and that it was safe. At the height of the "current war" between Tesla and Edison was the Chicago Worlds Fair - and it was to be powered by electricity. Tesla's alternating current. But Tesla had even more tricks up his sleeve: developing the turbines and generators that would convert Niagara Falls into electricity to light the homes and streets of Buffalo.

Tesla was a man full of ideas: could tides be harnessed to produce electricity? What about the spinning of the planets? Back matter includes further information about the rivalry between Tesla and Edison, explanations about DC and AC current, and how a spinning crank makes electricity.

Today is STEM Friday - head over to the STEM Friday blog to see what other bloggers are reviewing.   Review copy provided by publisher.