Thursday 23 January 2014

Skating Questions

Skating on New Years Eve
It's been a busy winter so far, and I seem to be spending it in a lot of it on ice - skating lessons, hockey games, hockey practices, hockey tournaments... at least some of the games are mine! And when we have free time, what do they want to do? Skate. But all this gliding around (and skate tying) has led to another batch of short answer random questions, so I present to you our skating conversations (minus all the requests for hot chocolate).

How does the Zamboni work?
Well, let me start by saying that Zambonis are awesome, and every kid (ok, adults too) pretty much has a fascination with them. They were invented in 1949 by Frank Zamboni in California of all places! They are technically called "ice resurfacers" and Zamboni is a brand name, but it's way more fun to say so I'll stick with that. They have a few parts - a snow container, hot water tanks, a wash water tank, a conditioner, and a brush. The conditioner is lowered to the ice with a large, sharp blade to shave off the top layer of ice. The shavings are then  sprayed into a large snow container. The wash water sprays the ice removing any snow and dirt and a squeegee and vacuum picks the water back up, this water is filtered and reused. Some have a board brush that cleans the boards when the machine is on the outside of the rink. Then a layer of hot water (60°C) is put down from a sprinkler pipe and a cloth towel dragged behind which fills up all the skate marks by melting the ice below and bonding to it. And we are glad it does all this because fresh ice is the BEST.  


 
How come it can snow and rain at the same time?
So apparently the answer "because it's Ontario" is not sufficient here. Although it's true - plus you can add in ice pellets for a trio of winter precipitation all at once! According to wikipedia in the US they call all three together "wintry mix" which we all agree sounds like it should be a type of candy. Here we refer to rain/snow as "sleet" or "November" but apparently in the US the term sleet is used for the ice pellets (which we just call ice pellets). It is is also not to be confused with freezing rain, which is actual rain that freezes on contact (and caused all kinds of problems south of here around christmas). So when does the rain/snow mix happen? When it's snowing but the atmosphere down in the lower part is above freezing, so some of it melts, but some of it doesn't and you get a mix of soft snow and rain.

The moon is following me. Why is it out in the day?
The moon isn't just out at night, it orbits Earth independently of the sun. So, when it's here in daylight hours you can see it when the sun illuminates it. And that's why sometimes at night you can't see it.

Popcorn!
Another post skating staple, popcorn is the seed of a specific kind of corn, Zea mays everta, that has a hard, impermeable (waterproof) hull that is filled with starch and water. When it's heated up the water turns to steam and the starch turns to a gelatinous substance. The pressure build up until the hull bursts and the starch puffs out - the pressure hits 135psi! There needs to be about 14% moisture inside for the popcorn to pop, and it ends up about 50 times it's original size. And then we stuff our faces with it (OK, the last part isn't part of the science answer, but it's a key step in popcorn).

http://www.popcorn.org/ForTeachers/TeachingGuide/WhatMakesPopcornPop/tabid/88/Default.aspx

 

Why is ice slippery?
 Sometimes there is a question with no good answer, because science just doesn't know yet. Although, physics is working on it. Could be friction causes the ice to melt a bit, could be that ice inherintly has a "liquid" or "liquid-like" layer on it that causes the slipperiness, could be some combo. But whatever makes it slippery also makes it fun!

Now get some blades on and go have fun!
(and don't forget the hot chocolate after)


...and yes, I do want to drive the Zamboni.