Science You Can Really Sink Your Siege Engine Into

So you've got a large-scale model medieval siege engine in your garage and you're just not sure what to do with it? Maybe it's a trebuchet that was used to fling large large rocks into castle walls or dead cows over them. Well, castles are pretty hard to find nowadays and don't even get me started on dead cows. So what is to be done?

Well, you know who loves to throw things? Kids. So take your thingamajig tosser and do some science.

That is exactly what we did last week. Some of the children at Akany Avoko rolled up their sleeves and helped build a couple of meter tall trebuchets. A few adjustments here and there and they were ready for some good hands-on science teaching.

We had a warm-up lesson exploring the basics of levers, but on Friday we were ready for the real thing.

The two teams of 4th and 5th graders loaded up their trebuchets with tennis balls and prepared for battle. Each team was at one end of a basketball court and had to try and hurl the ball at a target on the other end. Hit the target three times and win.

Three, two, one...jump back and fire! After each shot the machine was adjusted and fired again. The lever arm of the trebuchet had three different settings to choose from.

The losing team had to face a firing squad! It was a water balloon firing squad, so it wasn't as bad as it sounds. The winning team got to fling one balloon at the losing team.

But then we made it fair. We moved the trebuchets closer and both teams switched from tennis balls to water balloons! Sounds a lot better than a science book doesn't it?

The trick was firing at the enemy without getting sloshing wet from an incoming balloon yourself.

Sometimes there was just nothing to do but take one for the team.

But really, on a toasty hot afternoon, who doesn't want to be drenched with a water balloon.

[Click here to see and learn more about trebuchets from PBS's Nova.]

[Click here to attack at castle with a virtual trebuchet game.]

Waving Goodbye to the Dinosaurs and A Prickly Proposition

Three more photos that can't stop talking. Listen to their blabbing and see what you learn (or would that be hear what you learn?).

Head to the beach and munch on some fries and watch a wave. It didn't last too long did it? A few seconds and the wave was gone. Dogpiled by a few dozen other waves from behind. But take a gander at the photo.

The mountain we are on is about a 10 hour drive to the closest beach, but those there be waves in the stone. That rock used to be a nice sandy shoreline with gentle waves lapping at its grains. All those ripples were then trapped underneath some gush of more sand or mud from a flood or storm. Keep adding more sediment on top and all that weight plus a whole lot of time turns that bumpy beach into a rock.

So how old are these frozen waves? I'm not too sure. It's hard to do research here even with Google (amazing I know). It could be 1000 million years old. The last dinosaurs said bye bye about 65 million years ago. Think about that. The wavy rock is like a thousand year old man compared to a 65 year old man. That's a big difference.

Hairy be wary! Not only does that little saying help you to avoid poison ivy vines in the woods and very old leftovers in the fridge, but it also can keep a sleeping moth from getting the better of you. Some caterpillars are plump smooth and wrinkly little buggers. And some have a full head (and body) of hair.

The hairs aren't for looks. On some caterpillars, the hairs are for fightin'! Caterpillars are tasty little treats, but being tasty can end badly. To keep from being a juicy appetizer, they surround themselves with bristling hairs of DEATH! Ok, not really hairs of DEATH! More like hairs of annoyance. Some caterpillar hairs are full of a mild venom that can make you or a hungry lizard quite itchy. The hollow hairs have special tips that break off and release the pesky poison.

Other hairs have nasty hooks on the end that poke right into an enemy's skin, but they don't poke back out. All great ways to keep off a dinner plate, but what happens when the soon-to-be-moth finds a cozy little place and starts its metamorphosis? Those hairs won't do a whole lot good on the inside of a soft and silky cocoon. But they would make a dandy barbed wire fence. Some moths pluck or pop off their hairs and weave them right into their silky cocoon to fend off famished foes as they pupate their days away.

The photo shows some of those hairs still standing guard even long after the moth has flown away. And do they really work? Ask my wife who was still picking the hairs out of her skin 5 hours after this photo. See if she ever eats a caterpillar again! (Don't freak out. My wife doesn't eat caterpillars. At least not that I know of.)

Hey, where's the popcorn? Think about the last time you went to the movies. Think of all the lights and posters and candy and popcorn and soda. Think of the 18 other movies playing in the theaters all around yours. Well, this little wooden shack is not a storage shed; it is the local cineplex. And there was no popcorn at this movie theater. There wasn't even electricity at this movie theater. Well, sort of. They used a small gas-powered generator to give the little TV and DVD player some juice. People sit on skinny little wooden benches or just stand. It may not sound like much, but it is a bargain. A ticket costs only about 15 cents.

It's True, a Picture of a Dead Fly on a Flower is Worth a Thousand Words

Or maybe slightly less than a thousand words, but this picture does have a lot to say. For one thing, look at the cool animal on the flower.

How many legs?

Six.

How many body parts?

Three.

Is its mouth shoved smack into some delicious nectar?

Sure is.

So it must be a bee, right?

Wrong.

Bees aren't the only insects that slurp up tasty energy-packed nectar. Flies do too. Some flies anyway. Other flies eat blood or, believe it or not, poop. But the one in the picture is a nectar lover. Insects eat nectar because it tastes good and it has lots of energy.

So plants make the nectar for the insects, because they love their six-legged friends so much, right? Not quite. Plants want the insects to come for the nectar, but while they are enjoying their delicious snack the insects usually get a bit of sticky pollon stuck on their furry legs and such. Look at the fly and you will see all the hairs. When the insect buzzes off to get another snack, it picks up some more pollen, but it also drops a bit of the other pollen off.

This is how plants get married and have babies. Fine, plants don't get married. But they do make babies. We just call them seeds. Their babies may not cry and pee and poo, but seeds to grow up to look just like their parents. And since plants don't walk, the only way for pollen to get from one plant to another to make the babies/seeds is with the help of some flying furry friends.

Let's see, what else can this picture tell us? Well, see how close that photo is? Try getting that close to a living buzzing fly sometime. It's not easy. But it is quite easy to get this close to a dead one. Yep, that fly is dead (I'll give you a moment to cry and send some flowers)...

...Ok, so why did it die with its mouth stuck in a flower? This picture was taken in the middle of the island of Madagascar. The island may be tropical, but that doesn't mean the whole place is nice and toasty and covered in coconut trees. The middle of the island is more than a mile above the ocean. And the higher you go up, the thinner the air gets. Air is like a blanket. A thick blanket is warm. A thin blanket is cooler. The thinner blanket means it gets cold at night. Sometimes even cold enough to snow in the tropics.

Flying insects don't like the cold. When it gets too cold, they can't fly. If they can't fly, they can't eat. If they can't eat, they can't get any energy. Without energy, their three little body parts get cold and they die.

Flies don't build hives or cozy nests like bees and wasps, they have to find a warm place each night. And a flower is great choice. Flowers are like little heaters. They make heat the same way you do. If you are cold, you do something. You run around, rub your hands together, shiver, shake, eat. Plants may look like they just sit there and stare at the sun, but they are all together quite as busy as the bees that land on them.

Even at night they keep working away. Plants don't sleep, they spend the night breathing just like you do. They puff out carbon dioxide and other gases from their leaves just like you do from your mouth. That puffing means things are moving inside of them and making them warm. Now during the day the plants were busy making food from the bright rays of the sun. At night, they sit down (so to speak) and eat all that wonderful food. That eating and digesting also makes them all warm and cozy. The chilly fly landed on the flower to get a bit of nectar and cuddle with the warm flower for the night, but it wasn't enough. The fly was just too cold or just too old and she went sleepy sleep forever.

Wow, this picture sure is talkative. It had a lot more to say than I thought. Right'o, but it's not done blabbering yet. Take a close gander at the rest of the plant. What do you see bristling here there and everywhere? Hairs. Those hairs mean a lot. The middle of Madagascar has two big seasons. A wet season with lots and lots of drizzles and drops and storms and a dry season with lots and lots of sun and heat and dust. If a plant wants to survive the dry season and drink till its little roots' content in the rainy season, it needs a way to get and keep all the water it can.

The tiny hairs act like a jacket to protect it from the cool nights and the hot days. Wait a second! How does a jacket help when it's hot? The hairs make a wet jacket by holding onto the nice damp morning dew. Then the dry air can suck up the dew from the plant's wet hairy jacket instead of the water inside of the plant. This particular plant, a pachypodium, also has a nice thick juicy stem full of water that it sips throughout the dry season.

Ok, I will tell the picture to shush up for now, so you can back to your learin' and such. Thanks for listening and please enjoy the much less talkative pictures below. They are from a wonderful trip last week to the mountains of Ibity in the central highlands. Come back Wednesday and Friday for more pics and tidbits from the trip.

Take care.

My wife, Cindy, and a few houses of the lucky souls that get to live in this beautiful backdrop.

Without a doubt, the coolest and most colorful six-legged beasty I've ever seen in person.

This yellow frog does not seem amused.

This lizard has some dandy camouflage that helps it hide from the birds and sneak up on the juicy critters that also linger on the rocks.

This we didn't have to sneak up on. After a long morning of hiking in the sun, we enjoyed a big plate of sweet boiled manioc. It's a potato-like root you won't find on many menus in the United States.

What is It? Video Addition

Click on the video below and see if you can answer the question:

What is it?



So, is it...

1. a baby snake
2. a leech from some lettuce we just bought
3. a gecko tail
   
4. a centimeter worm (we use the metric system here)

I will leave some a bunch of blank space here so you can't cheat and see the answer quite yet. Make a guess and then scroll down to find out what the little wiggly thing is.



















So, what is it? Well, it is actually a gecko tail. Geckos are ravenous little skeeter eaters (they eat lots of other insects too). But just because they spend their lives eating dusty-winged moths and other mouthwatering treats, doesn't mean they don't find themselves on the other end of the fork occasionally. That is to say, geckos eat some things and some things eat geckos. Birds, other lizards and geckos, or in this case, our dog.

Our dog saw a four-legged long-tailed toy running down the sidewalk and tried to play with it. The gecko didn't care for the game, but it was a bit too slow. Our dog snipped her pointy puppy teeth right onto the gecko's tail. Ouch!

No problem. The gecko had a secret weapon...the tail is a break-away. It snaps right off like a piece of Legos. Our dog ended up with a tiny tail and the gecko ended up with a scary story to tell all the other geckos around the campfire that night.

Lots of lizards have this nifty feature. Some don't even need a dog to help snap the tail off. They can just flex their little lizard muscles and pop their own tail right off. But the tail has little muscles of its own too. And those little muscles keep twitching and flipping around so that the tail looks like a tasty treat too. While the hungry gecko-eater is getting ready to munch of the delicious market-fresh all-organic tail, the rest of the gecko is getting away and living to flee another day. This particular tail kept on dancing around for over 15 minutes after the gecko left it behind.

Giant Leaf-Tailed Gecko from Madagascar

It doesn't hurt the gecko and special cells even keep it from bleeding. Geckos do store fat in their tails, so it does lose some of its well-deserved energy. And until a new tail grows back (yep, they just grow a new one), they can't use the cool tail trick to get away from predators.

And how cool is this? Sometimes a bit of tail is left behind, so that little bit grows back into a full-sized tail too. Add that to the new tail it normally grows and you end up with a two-tailed gecko.

What Mr. Lebo did During Your Summer Vacation...in 500 Words or Less

The tremendous and towering baobab trees of Madagascar.

Welcome back! Tonga soa!

I hope you had a marvelous summer in Princeton and elsewhere. I myself just had a wonderful winter here in Madagascar. Don't forget, I'm on the upside down part of the world, the southern hemisphere. While you had a hot and sometimes rainy summer, I had a cool and very dry winter. There was even a tiny bit of snow one day on our lovely tropical island, but I didn't get a chance to see it (it's quite a big island too).

Now that you all have started hitting the books again, the blog will be up and running too. I will put up a new post each weekend, so you will have all week to check it out and leave some lovely comments. Don't forget to vote on the What is It? poll on the sidebar too.

Enough words. Let's see some pretty pictures of what I've been up to.

My wife's sister and father came over for a fantastic visit this summer and we went to some great places together. This is from a hike and climb through the crazy rock formations of the tsingy limestone.

My wife and I are dressed up and dancing, but we are not at a wedding. We are at a Malagasy funeral and we're doing the conga around 5 dead bodies that were just dug up from an underground tomb. Don't worry, you'll learn more about this later.

I got to go on a trip and picnic to the zoo with the fabulous kids from the children's home, Akany Avoko. I volunteer there 4-5 days a week as a carpenter, furniture maker and science teacher.

Of course, I got to see some more cool animals like this beefy chameleon here.

And this big-eyed nocturnal lemur.

And this big-eyed-nocturnal-lemur-eater also known as a fosa.

I also volunteer as a medic and English teacher with the Malagasy Red Cross. On this day, I was lucky enough to be a stretcher carrier at an international soccer game, Madagascar vs. Brazil. The fighting bulls of Madagascar actually won 3-1. And I had a better-than-front-row seat right on the sideline.

Some great friends and family members donated money for me to fix up the wood shop at the children's home and now I teach woodworking to the kids once a week too. Valentine made this crafty wooden plane.

Every time we travelled, we and our white skin seemed to always attract all the kids' attention.

We found this adorable stray puppy and adopted her into our home and hearts. Sadly, she became sick and passed away just a few weeks ago. Her name was Kibo and we miss her very, very much.

I ate lots of delicious Malagasy food like this plate of green papaya salad that cost a whopping 7 cents.

Cindy and her sister enjoyed playing with kids when we travelled.

I saw some beautiful natural sights like this glorious sunset.

And there aren't any ice cream stands or hot dog vendors like the Jersey shore, but we did get to the beach too. Quite pretty at least.

If you want to see and hear more, just keep coming back. I will be putting up whole posts about several of the great trips I had this summer. And of course all the adventures yet to come as well.

I miss you all very much.

(For the picky ones among you, I actually used 591 words not the 500 words or less I promised. Sorry.)