Tuesday, 24 September 2013

Chomp Chomp

Bunny has been losing teeth for a while now - with 8 now having gone under the pillow. Naturally this has brought up some teeth questions such as: How many am I going to lose? (Quickly calculated as how much money can I make off this "tooth fairy" character). How many teeth does the cat have? How come some are pointy? Etc, etc... These discussions usually end with Beans desperately yanking on her teeth in hopes that she'll get a toonie under her pillow shortly. This has recently increased with one of her buddies losing 3 in the past week.

Tooth pictures borrowed from the Canadian Dental Association

Humans have 20 primary teeth (also called baby or deciduous teeth) and 32 secondary (permanent) teeth. Why the difference - we don't have the same amount of molars as a baby and there's an extra set of bicuspids that come in, and those just come in at various times and we keep them, and there's the whole wisdom teeth thing. Only the first set of teeth fall out so, if all goes according to plan, there will be 20 visits from the tooth fairy. The crazy thing is that they are all in there, some of them are just hiding and waiting!

Look at 'em all in their little slots just waiting!
Bunny thinks this picture is cool
Beans does NOT want to look at it again

Tooth strategies go along with eating strategies. There are the three basics - carnivore (meat), omnivore (everything), and herbivore (plants). Then there's some specialties within those - like insectivore (insects) and piscivore (fish) in carnivore and gnawers (rodents) vs grinders (deer, cow, moose, etc) in herbivore, but for the most part mammals fit into one of those three main groups. Humans evolved as omnivores - so we have teeth for tearing and biting, but also ones for grinding - pointy in the front, flat in the back (like the bear below). Think about the different ways you would eat different types of foods - we thought about chicken drumsticks vs salad - and how you used the different parts of your mouth for different eating "jobs", you couldn't chew lettuce with your front teeth or tear chicken with your back ones. And as Bunny pointed out, ice cream doesn't need teeth, so if she loses more she could just eat ice cream. Nice try Bunny - icecreamivore isn't a thing.

Herbivore (Deer), Omnivore (Bear) and Carnivore (Cougar)
From: http://www.skullsunlimited.com

I asked the girls to each pick an animal so we could look at it's teeth. Luckily they each picked very different ones, although both are mammals, so we're not looking at two of essentially the same thing. That could have totally backfired on me!

Bunny's Choice: Chipmunk
I think this choice is influenced by our extraordinarily busy chippy that lives in the yard and fills our downspout with stuff. He's been whipping around lately getting ready for the snow and has dug a cache in our plant pot out front (which reminds me I should get the mittens out as we've already had some frost). Bet you all thought chipmunks were herbivores (Bunny did) - well you all would be wrong! Omnivore! They eat bulbs, seeds, nuts and grains but also insects, worms, frogs and bird eggs. However, as it is mostly seeds, cones, and veg based, they do have the continuously growing prominent front teeth of the rodent family - because of the amount of "nibbling" they do, rodents wear out their teeth quickly so the continuous growth means they always have something to bite with. Along with their four sharp, chisel-like incisors, they have flat back grinding teeth as well.

Chipmunk Skull
Large incisors and flat "grinders"
From: http://www.skullsunlimited.com
I'll just tuck this away here for later....
By Gilles Gonthier from Canada via Wikimedia Commons

Beans' Choice: Lion
I assume this is prompted by our recent zoo visit at which lions and elephants were her clear winners. Personally, I thought the hippo who did a sashay runway walk for us was quite delightful. Lions have 30 teeth, so pretty close to us. That's pretty much where the similarity ends though - Lions, and cats in general, eat pretty much one thing - meat. Unless you are our cat Havoc, in which case you also include house plants, strawberry tops, lettuce and the much coveted "outside grass". They only have tearing teeth - everything is pointy with no flat "grinders". A lion's back teeth are like a pair of scissors which basically cut up whatever zebra or wildebeast happens to be dinner. There is no chewing at all - they basically swallow chunks (which is why I suppose when Havoc throws up the plants that they are indeed in chunks).

My how pointy your teeth are!
All the better to eat you with, my dear...
By Brocken Inaglory (Own work) via Wikimedia Commons

Oh yeah - domestic cats have 30 adult teeth, they have 26 baby teeth and lose them. So somewhere out there is a feline tooth fairy leaving sardines under a pillow.

Here's a super fun game about teeth! (click it for a bigger version)


Wednesday, 11 September 2013

Fire and Water

We are a campfire family. There isn't much we'd rather be doing on an evening then hanging out around a campfire. There's just something so relaxing and meditative about watching the flames or, even better, roasting something on them. In fact, one of my favourite presents this past year was a s'mores roaster - that's right - the WHOLE s'more gets toasted, not just the marshmallow, made exceptionally better by the use of dark chocolate and occasionally the addition of peanut or almond butter. No one can deny that fire is pretty awesome and people and fire go wayyy back. Plus there is the ever exciting "adding a log" or "poking with a stick" - a good fire pokey stick is intrinsically important. We don't really care where the fire is - park, shoreline, backyard - anytime is fire time (except during fire bans obviously).

Fire + Food + Goofy Children = Awesome family time

We've taught Beans and Bunny from a very early age all about fires and fire safety. The important rules like no running near the fire, keep a bucket of water nearby, don't leave a fire alone (they get lonely) and don't put your marshmallow directly in the flame. It was one of those rules that prompted this post - the bucket of water. It wasn't the why of it, they know to keep it there in case the fire jumps out of it's little circle and for end of the night dousing. It was the how - how does the water stop the fire?

It is hard to take good campfire pictures at night with a phone

The answer to this one is pretty simple so to make it a nice, well rounded post I'll also put in assorted random campfire pictures of us or food or us with food.

Who doesn't love cooking stuff on a stick - SPIDER DOG!

To answer the question we first have to know how fire works. A campfire is an exothermic reaction involving the release of energy rather than endothermic, one that sucks in energy, which is why it has a lovely glow and toasts things. The burning of wood is combustion - a rapid oxidation reaction that releases energy in the form of heat and light. To catch things on fire you need three things - fuel/combustible material (wood), and oxidizer (oxygen) and a heat source that gets it past the flash point of your fuel (lighter - which does it's own mini reaction with a gas, oxygen and a flint spark). Once lit the whole thing continues in a chain reaction and it sustains itself by it's own release of the heat and with a continuous supply of fuel and oxygen it will keep going (the aforementioned "adding a log" fun). 

Behold! I have combined wood, oxygen and heat! Muahahaha!

Stuff fire needs

To stop fire you need to take away at least one of the things it needs. Water takes away two - it stops the fire from being able to access the free oxygen in the air by displacing it and it turns to steam (usually quite dramatically), which carries the heat away from the fire and lowers the temperature back down so it no longer burns. Even though water has oxygen in it, it is bonded to the hydrogen and not accessible for the combustion process.

Cool Fact: Astronauts can't have campfires because the process depends on gravity to constantly supply the fire with oxygen. Without gravity the fire will quickly have only have only it's own combustion products surrounding it and extinguish itself.

Astronauts cannot have this fantasticness.

And now, as promised, more pictures of campfires:

A nice Georgian Bay shoreline fire
Cooking stuff on a stick is good, but this is a definite step up!
A little Bunny + A little fire
Everyone loves Bannock-On-A-Stick. Extra good with maple syrup.

Click here for some tips for safe campfires!

Friday, 6 September 2013


Bunny and Beans are outside

Well, it's been a whole year of blogging. I've had a lot of fun writing about the adventures of Beans and Bunny and all the questions they've come up with. I hope you've enjoyed reading about us and maybe even figured out a little about our crazy amazing world and the science and nature that make it tick.

Read our very first post here

Beans and Bunny are very involved in this blog. They not only ask the questions, but they help find the answers (OK, Bunny a bit more since she can read more than random letters, "and", "is", "the" and her name) and then the most important thing - they then know the answers and can spread that fascination of nature to all they meet. And they do - just last week Bunny explained all about crane flies to her camp group (including the counsellor) who were calling them "giant mosquitoes" - I feel a great many crane fly lives were saved that day. As knowledge grows, so does respect and care - and that's really what is important. Plus Beans explaining watermelons are a berry to a random lady in the grocery store is highly amusing.

But enough with the mushy stuff. Thanks for reading and sharing and helping us grow this past year. There's a never ending supply of questions in their heads so I don't see us stopping anytime soon.

And I swear, someday I'll finish that book.

Tuesday, 3 September 2013

Fish Breath

First off, this is another post with a sountrack. Another good Canadian band too. So hit play and then read the rest. Or watch the video and then read it, or play it again for the reading part... really, it's up to you.

Alright. So this question has now been asked independently by both girls, so it's high time we addressed it on here. Bunny asked in relation to one of her favourite pastimes - fishing. Now even cooler with her new birthday fishing rod that LIGHTS UP with LED lights when you reel in. Spinning lights and multicoloured fluffy lures - what more could a little girl ask for. She was standing on the dock, staring down at the fish, which were currently not being fooled by her pink, sparkly bait. How do fish breathe underwater?

Above all, fishing teaches you patience

Or in Beans' case - how come she can't. Her version came from in the lake: "Are you SURE I can't breathe underwater? Like really really sure? Dory can though?" (Dory is her Betta, Bunny's is named Flamingo) And then me convincing her that really, it's not in her best interest to try and handing her a snorkel. Then a few days later as that Metric song came on in the car - "Are you REALLY SURE? Because this song is about breathing underwater" and "How come I can drink water but not breathe it?" - which was easy to answer because they already knew about the whole two pipes thing for breathing and eating and just required a short update to include the epiglottis.

Beans' fish impression

It is a good question, because fish do breathe and need oxygen circulation just as much as we do - they just do it very differently and in a whole other substance.

There's two main kinds of fish: Bony fish (osteichthyes) and Cartilaginous fish (chondrichthyes) but in general the mechanics and equipment for breathing are similar. In order to breathe, fish take in a mouthful of water, pull the sides of its throat together and force the water through the gill openings where is passes back out to the lake/river/ocean/aquarium from whence it came. Gills in general too are built the same. They have a large surface area to gather a lot of oxygen at once and a good blood supply so that oxygen has somewhere to go.  In a litre of freshwater the oxygen content is 8 cm3/L compared to 210 cm3/L in the same volume of air, so they need to be pretty efficient. 

Water flow for breathing
Gills for real (from a tuna)
This Wikipedia and Wikimedia Commons image
is from the user Chris 73 and is freely available at
under the creative commons cc-by-sa 3.0 license.

Bony fish (bass, pike, perch, bettas, general things we think of as fish) have an operculum - which is a bony cover over the gill that can be used regulating the flow of water. This allows them to breathe without moving and to maximize their oxygen intake with a countercurrent flow. Oxygenated blood moves through the gills one way while de-oxygenated moves the other way, not too far off from how our artery-vein system interacts with our lungs. This is why when they are still you see the plates moving in and out, pushing water over the gills to keep up with respiration.

Countercurrent flow for efficient breathing

Many cartilaginous fish (sharks mostly) don't have operculum or the ability to pump water so they need to continually swim to keep water flowing over the gills. Gives new meaning to the little ditty from Finding Nemo, eh? "Just keep swimming" - they literally have to in order to breathe! Because of this they don't have the efficient countercurrent flow that bony fish have and why it sucks for them to get trapped in a net - no movement = no oxygen and they suffocate.

Open gill slits in a Nurse Shark

So Bunny is now vigilant to get her fish back in the water quickly. And as Beans has lungs and not gills, she can't force water over them the same way that Dory does any more than Dory can come up here and breathe air. Which means she is stuck with that snorkel for long term swimming (and I suspect scuba is in her future).