How Tall Is Your Tree?

Post by Helaine Becker

How tall is your Christmas tree? Or any tree for that matter?

Use this  fun and super easy STEM activity to find out any tree's height without a ladder. It relies on trigonometry!

1. Get on your knees and put the top of your head on the floor.
2. Look  through your legs at your tree. Can you see the tippy top?
3. If not, move away from the tree until you can.
4. Mark the spot where your head is touching the ground.It's the same distance from the tree as the tree is tall!

Paddling the Ice Kap

No, I didn't get up North or to Antarctica, to paddle my kayak at either of the actual ice caps. Instead I got to try out a kayak model called the Ice Kap, from Sterling Kayaks. It was a great day to learn more about kayaking science. Yes, there's science in kayaking! There are all the measurements, when designing and constructing boats. There's also research. Which boat shape is good for racing, or for surfing in waves? And then there are the experiments. No lab coats and clipboards for me -- I just try the different boats and have fun, while my friends Louise and John keep a notebook of their own experiments with kayaks.

At the MEC Paddlefest on Willows Beach, we found an assortment of several models from Sterling Kayaks. Each is a custom job, with the foot pedals set to accommodate the paddler's own leg length, for example. I got to sit in an Illusion, but even with the footpedals adjusted as far as possible, my feet still couldn't reach. That would be no problem if I owned one of their kayaks, explained the designer, Sterling Donaldson. He would put the footpedals closer to the seat for someone as short as me. He's calculated the centre of gravity and balance points for all his kayak designs.

Donaldson gets fibreglass under his fingernails and epoxy all over his hands, he complained at one point. But there's no substitute for the hands-on approach when customizing a kayak for someone with special needs.

The foam seats are a terrific support... lifting the knees a little and fitting around the butt. I'm guessing that my partner Bernie would find THIS seat doesn't hurt his back. The seat back is good support, but low so that a paddler can lean back when rolling the kayak. On each side of the seat is a support for foam padding, to customize the fit to the paddler's thighs.

I got into the Ice Kap which is designed for small people. The coaming, the edge around the cockpit opening, is low. As in half-way up my thighs when I'm seated in the kayak. No more rubbing my elbows on the coaming with each stroke! That happens in most kayaks for me. The designer Donaldson pointed out, most shorter people are not only short in the leg, but have short backs as well. It's hard to roll a kayak that is too big.

My friend John Herbert  took a photo of me on the water in the Ice Kap. It's pretty clear in the photo that this boat has a lot of rocker, a curve which brings the keel up in the bow and stern. That makes for a lot of fun riding waves. I expressed some concern about the front deck being so high out of the water, and the stern so high. Wouldn't they catch wind and turn like a weather vane? "None of our boats weathercocks," Donaldson insisted.
The Illusion has a similar hull to the Ice Kap, but the coaming rises a little higher at the paddler's thighs and sides. John could tell that he wouldn't fit either model. At 6'4", he went for their Grand Illusion that fits the 6'3" designer. But the model on the beach had been padded to fit a thinner paddler. Not for John today!
Louise tried the Ice Kap as well, just to add another model to her research for which style of boat she would buy this summer. We compared notes. Afterwards, John and Louise changed out of their paddling clothes while I just wandered around evaporating. One of the most important things I learned about kayaking science is to wear clothes that evaporate dry quickly.
Our verdict: if you're a thin, short man or woman who is wanting an exciting kayak, try the Ice Kap for an experiment of your own. If you're not thin, try the Illusion as the coaming is just a little higher instead of pressing on the sides of your thighs.
And if you're a differently-able paddler (like every member of our paddling group, and plenty members of SISKA and VCKC and the entire crew of the Breaststokers Dragon Boat team), talk to a kayak designer about kayak science. How can a kayak meet your needs?
This particular designer understands. Sterling Donaldson not only talks the talk, he walks the walk with one leg and crutches on the beach among his kayaks. He grew up designing experimental aircraft with his father, and now he applies the scientific methods he learned to building kayaks.

Christmas counts - to the birds

By Marie Powell

As we start preparing the annual Christmas turkey (photo by tuchodi), tens of thousands of volunteers are out in search of other birds - on the annual Audobon Christmas Bird Count.

Before the Twentieth Century, many bird and animal species would need to fear the annual hunting parties in search of sport and/or food for the holidays. According to the Audobon website, this annual hunt turned into a bird-counting census on Christmas Day in 1900, when the idea was suggested by ornithologist Frank Chapman. In its first year, the bird count included sites from Ontario to California.

Today, Christmas bird counts are held across North and South America from December 14 to January 5. Bird counting usually takes place in groups within a defined area, and in all kinds of weather. The data collected helps scientists and researchers study the health of bird populations over time. That helps identify declining bird populations - and ultimately, declining populations tell us about the health of a given area or ecosystem.

It's a way of giving back - and when could that be more appropriate than at Christmastime?

For more about Christmas bird counts, or to find one near you, try these links:

Audobon: Christmas bird count: http://birds.audubon.org/christmas-bird-count#

Audobon: Get Involved: http://birds.audubon.org/get-involved-christmas-bird-count

Bird Studies Canada: http://www.bsc-eoc.org/volunteer/cbc/index.jsp?targetpg=cbcparticpate&lang=EN

Marie Powell is a freelance writer and author of Dragonflies are Amazing (Scholastic).

Just a spot of sun

By Marie Powell

With the onset of winter, I’ve been more interested in following the sun – on and off the web. NASA is a good source of up to date information about science topics, in easy-to-understand formats with lots of colour videos. Just looking at this sunspot from July 2011, for instance, warms me up.

Did you know sunspots increase and decrease in an 11-year “sunspot cycle”? The exact length of the cycle can run as short as eight years and as long as fourteen, but the number and intensity of sunspots increases over time, and then decreases again.

According to NASA, the sun’s poles reverse every 11 years, causing the sunpot activity. Sunspots mark the place of powerful magnetic fields from the sun’s interior, causing solar flares – a phenomenon we’ve been observing since Richard Carrington discovered it in 1859.

Lately we’ve been seeing sunspots and flares more often lately because the cycle we’re in now will peak around 2013 or 2014. Then it will begin to diminish again until around 2020. For more information about sunspots try these links:

Solar flares (November 2011): http://science.nasa.gov/science-news/science-at-nasa/2011/19sep_secretlives/

Sunspot cycles: http://solarscience.msfc.nasa.gov/SunspotCycle.shtml

A unique solar flare (July 2011): http://science.nasa.gov/science-news/science-at-nasa/2011/11jul_darkfireworks/

Marie Powell is a freelance writer and author of Dragonflies are Amazing (Scholastic).

Eleanor of Aquitaine Sundial

When I speak to schools and libraries, I try to find a way to show how science can relate to a child's life. But tying science to history and making it interesting is more difficult than it seems. Thanks to my writing partner, Leslie Johnstone, I have the perfect way to capture a child's imagination.

Look at the picture on the left. Is this science or history?

Usually kids guess that this is the "One Ring" from Lord of the Rings as it has markings on the inside and outside of the piece. But the writing isn't Elfish.

On the outer rim of the ring are the letters " J F M A M J J A S O N D" and on the inside of the ring are the numbers 1 through 11. There is a brass ring that rotates around the centre of the ring and in the middle of this ring is a round hole. Engraved inside the ring are words, "Carpe Diem" or "seize the day."

So other than a really cool piece of jewelery and very nice birthday present from my best friend, what does this pendant have to do with science and history?

You are looking at a replica of the Eleanor of Aquitaine sundial, based on the one the queen gave to her husband, Henry II of England in about 1152. Right about now kids yawn.

Most children have never heard of Eleanor, Henry and know nothing about the Aquitaine. However, ask a child if they have ever heard of Robin Hood and most hands go up. Ask them if they know which king went to the crusades with Robin Hood most know the name of Richard the Lionhearted. And generally kids will have heard of his evil brother, King John. Now you have their attention. Let's not get into the fact that Robin Hood as portrayed in movies and books, was fictional.

When Eleanor married Henry, she was one of the wealthiest and most powerful women of her time. Marrying Eleanor was a pretty smart move for Henry as he now had access to money, lands and political influence. Eleanor like throwing lavish parties and wanted Henry to be back in time for dinner. Now frankly telling your husband he needed to be back at the castle no later than 5 pm had no real meaning as well, wrist watches would not be invented for another 500 or so years.

To solve this problem, Eleanor had a beautiful sundial made for her husband. This way he could always tell what time it was. Henry also commissioned an even fancier one for his wife made from gold and set with diamonds. And how did this romantic gesture work out? Sadly, there wasn't a "happily ever after" ending. Henry imprisoned Eleanor in a castle and went off to hunt and party to his hearts content, never having to see what time it was on his sundial watch.

Now the science. Turn the dial so that the hole aligns with the month. Turn the hole towards the sun so that a ray of the sun shines through the hole. Where the ray lands will tell you the hour.

Did you know?
When asked most people will say that "A.M." means "after midnight". In fact a.m. and p.m. mean "Ante Meridian- Latin - before midday" and "Post Meridian- Latin "after midday".