Australia Lesson Activities - Science

THEME: Birds
SUBJECT AREA: Science
TOPIC: Order Psittaciformes

2001 October 17, Wednesday.

Parrots belong to the faunal Order (or family) of Psittaciformes. Their bright colours easily distinguish them, along with their short hooked beak, and feet with two toes directed forwards and two directed toward the rear.

Parrots are unique in the way that they are the only bird (other than ‘Big Bird’ from Sesame Street) that can use their feet like we use our hands; they pull apart their food and feed themselves using their claws, which they manicure painstakingly. All parrots use their beaks for climbing.

Parrots are herbivores, feeding primarily on seed and fruit. They are also monogamous, staying with a single mate for their entire lifetimes, and, apart from the few which migrate in search of food, (nectar feeders) they tend to be sedentary, that is, to stay in a single area all their lives, and use the same nesting place each breeding season. In the wild, a parrot will live for over one hundred years. The size may vary ranging from the Goliath cockatoo (60cm) to the Budgerigar (12cm).

The two sub-families that are seen often are the Cockatoos (Cacatuidae), Lorikeets and Typical Parrots (Psittacidae). Parrots are the most intelligent species of bird, in the way that they have the largest memory for detail; and this causes each individual bird to develop a complex and very distinguishing personality.

Every type of parrot has its own distinctive characteristics. They also learn to speak, and imitate other sounds from their external environment. This is done by pet birds in a simple attempt to communicate with their owner, who forms an emotional substitute for their mate in the wild.

Most Parrot species mature at around twelve months of age. They nest in tree hollows and termite mounds, and for this reason their eggs are white. Birds who use an open nest in a tree or on the ground develop colour and speckles in their eggs, to protect them by camouflage from animals such as reptiles who might find them a tasty meal.

Parrots, like other species of birds, have a single oil gland at the base of their tails, in place of the ones we have all over our bodies, to lubricate our skin. The oil is collected from this gland in the beak, and spread across the feathers, one by one, to protect them. This is called preening.

Suggested learning activities: Find an animal whose life expectancy is over one hundred years. Find out what they feed on. Are they herbivores or carnivores? How large is the animal?

feed your children wheat
joshua and bel

THEME: Creepy Crawlies
SUBJECT AREA: Science
TOPIC: SPIDERS!

This morning, while I was packing up my swag, or sleeping gear, I heard a shriek from Mike’s tent. Jason and I went over to see what was up, and Mike told us that a spider had just fallen out of his sock while he was putting on his shoes. It was a Tarantula spider about the size of the palm of one’s hand. The story, being told to the rest of the group, was of a 10-pound spider the size of a small dog! Could you imagine a spider that size?!

Here are some neat factoids about spiders:

- All have eight legs.

- Insects have six legs. That is one way to differentiate a spider from an insect.

- Some spiders here in Australia can become as big as a mouse! (And as hairy!)

- Most spiders feed on solely on ants. There are more than 200 species of ants in Australia!

- Spiders forage for their food mostly at night. Some hide in their borrows waiting for prey to come along.

- All spiders are carnivorous, meaning they only eat meat.

- Sheet flooding, where water flows like a sheet over the desert is the greatest hazard to spiders living in their burrows. Many spiders build trapdoors similar to a plug used in your bathtub to keep the water out.

- Many spiders’ venoms are poisonous, so you should be very careful and aware of them!

Every morning before I get up I check my shoes and see if any ‘little dude’ has made a home in them! I’ve been fortunate to see a few, but none as big as Mike’s this morning!

*By Crister

Suggested Activities:
-Can you find any other neat info about spiders?
-Just like snakes, spiders are usually killed when discovered by humans. Can you think of the reasons why this happens?
-Find a spider’s web and make a list of any prey caught.

THEME: Limestone Gorge
SUBJECT AREA: Science
TOPIC: Rillenkarren

Following the advice on the National Parks Commission sign, we visited the Calcite flow at sunrise, to watch the morning light sparkle on the cascades. This white formation appears in the steep dry creek bed as a rushing waterfall, frozen in time. The turbulence of the fast flow of calcium-rich waters down this slope forced carbon dioxide (the same gas which animals convert the air they breathe into) out of the water. This chemical reaction results in the release of solid calcium carbonate (called calcite) from the water.

Over time, layer upon layer of calcite sediment builds up around solid objects – in this case, tree roots and rock. Eventually we are left with the striking white cascades we saw at Limestone Gorge, which could easily fool an uninitiated onlooker to think that water was flowing there.

Each wet season, the calcite cascades trap minute algae and other small organisms, causing them to change colour until they die in the dry season, leaving the white calcite exposed.

“This site holds particular significance for the local Ngariman Aboriginal people. It forms a part of their Flying Fox dreaming, which extends across many of the watercourses and natural features of this area. Traditionally the white calcite (Kulge) was used to make body paint for ceremonial purposes which were held in the vicinity of the present Limestone Gorge camping area.”

Near the Calcite flow, we saw a rock formation that had baffled us 65 days ago, in the Chillagoe caves, where another limestone founded land system exists. The exposed limestone surface resembles tiny choppy waves on a lake, with hundreds of sharp peaks, and, we finally discovered, is known as Rillenkarren. In Chillagoe, there had been no interpretive signs to tell us about it, and while the intrigue had been captivating, it was great to see it again, and to understand just how it was formed.

Rillenkarren is created by acidic rain - a very different type to that which cities may get from pollution. It is actually just a weak carbonic solution that is formed in the clouds. The carbonic solution dissolves the softer limestone rock causing a jagged, rippled effect. Dolomite, the type of limestone found throughout the park, is subject to rapid corrosion from many sources.

See Crister’s Geography update for info on some other neat geological phenomenon found in the Karst landscape.

The aboriginal people found a process that made splitting the rillenkarren easy. A chunk of rock is heated in a fire then cooled very quickly by dipping the stone into a creek. This gives the remaining rock splinters rather sharp edges, useful for crafting spearheads, knife-edges and axe heads.

Suggested learning activities:
Research the element Calcium. How much is there in the earth’s crust? Where is it found? What are its commercial uses? What purpose does it serve in our bodies? Find out all the practical information you can on this mineral.
Explore the commercial uses of Limestone. Many uses have been found for the stone in places where it is abundant around the world, just as the aborigines did. In the United States, it has been used for building fence posts, houses, flooring etcetera. What uses can you think of? What other types of limestone are there apart from Dolomite?

Feed your children wheat Joshua and bel

THEME: Road to Lajamanu
SUBJECT: Science
TOPIC: flies

The branch whacked me across the back of the head and shoulders, sending a multitude of flies into the air! When we’d left camp this morning, I was literally covered from my cap to my waist, including my arms, with millions of the pesky beasts. I looked like a scene from a Hitchcock film, flies crawling up my nose, in my eyes, out of my ears as I rode along, swatting furiously while trying not to fall off my bike on the sandy track. It was actually a relief to have Jason swat at them with the tree branch, even though most of them came back at me with a vengeance! They’d been an extreme nuisance to us all in camp the past couple of days and moving air, either from a breeze or from the back of a bike seemed the only relief.

So what is this phenomenon here in the Bush? The common fly occurs everywhere on the continent, but seems to prefer the wide open spaces. It roosts at night, but returns with first light of day. It begins its life in a dung heap, where creamy white eggs are deposited. The larvae hatch and, after eating its way through the dung, leave to pupate in the soil. The longer the larvae have to feed, the bigger the fly.

The adult fly needs a diet of protein; blood, pus, milk, tears, and saliva. That’s why their voracious appetites lead them to wherever we’ve scratched ourselves, sweated heavily, or near our dinner table at tea! And, the smaller the fly, the more starved it is for protein. Females in search of protein for their developing eggs seem to be the most tenacious of all, outnumbering their brothers three to one in search of essential juices.

The nuisance value of these flies has been measured. If we put our hand into a cage filled with them, ten blood-fed flies will be attracted to your hand per minute. However, if they are protein starved, the figure increases to 48 per minute. Flies with an underprivileged upbringing in a low protein dung heap, once adult and continuing to be undernourished, are up to 70 times a nuisance factor. These must have been the ones we’ve lived with the past couple of days!

Suggested activities: Investigate what attracts flies in your area. Compare the attraction value of table scraps, animal dung, sweat, to name a few, creating a graph of fly attractors. Which seems the most palatable to flies? Why do you think that is? What time of day are they the most annoying? Are there certain weather patterns that make them more of a nuisance? What is the role of the common fly in our ecosystem? Why is it important for them to be a part of the food chain?

April

Snakes are animals that many people fear when coming to Australia, and understandably so. The Australian continent is host to ten of the most venomous snakes in the world. The following may answer some questions you may have about these snakes:

What is the most venomous snake? The most venomous snake is the Inland Taipan. The second most poisonous is the Eastern Brown snake. Both are common in Australia.

Will a snake chase you? A snake will never bite a person for no reason, nor do snakes chase people just to bite them. A snake will only bite you if you aggravate it.

How can I recognise a venomous snake? It is very difficult to differentiate between a venomous and non-venomous snake. To be on the safe side, always presume the snake is venomous.

What should I do if I’m bitten by a snake?
Do not kill the snake (see today’s ESD update). You should also never attempt to wash the venom from the puncture site. Washing the wound may remove any trace of the venom, interfering with the doctor’s ability to decide which anti-venom to give you. Clean around the puncture site if you must, to remove dirt that might infect the wound. Bandage the bitten limb firmly, wrapping towards the heart and as far along the limb in both directions away from the bite as you can. Then send for help, and stay still.

Can you tell the age of a snake by how long it is? Because snakes grow according to their environment, not their age, you cannot tell how old a snake is by it’s length. A snake that has lived for ten years in the desert might be only half the length of a three-year old snake which has lived in a more lush area.

Are all snakes venomous? No, not all snakes are venomous, though most will bite you if you aggravate them. As a precaution, always assume a snake is venomous.

How do snakes move? With up to 400 vertebrae in their spine (compared to humans’ 29 or so), the snake has amazing flexibility and can move up to 10 km/h.

Think of some other questions you may have about snakes or reptiles in your area, and try finding the answers in a book or on the internet. Some questions to consider: What is the largest snake in the world? What climate does it prefer? What is the snake’s lifespan? What does it eat?

Feed your snakes and children wheat. Josh.

Our bodies are a beautiful example of a homeostatic system, that is, a system that keeps itself in balance. One example of this homeostasis is temperature regulation. Most of us have been out in snow or cold temperatures, and have started shivering. By shivering, our muscles contract and relax very quickly, which causes a buildup of heat, thus balancing out heat loss. In contrast, when our bodies overheat (due to a hot day, fever, or exercise), we sweat. When the salty water that appears on our skin evaporates, it helps the body to cool down.

Here in the Tanami Desert, we face daily air temperatures around 100 degrees Fahrenheit (36 degrees Celsius). You can imagine that when we bike under these sweltering conditions, we lose a great deal of fluid in our bodies to sweating. But where does this fluid come from, and what are the consequences of losing it?

The body’s water is stored in three areas: inside cells, between cells, and in the blood. In order to sweat, water is taken from these compartments and drawn out onto the skin, along with various chemical ions (also called electrolytes). One of these ions is sodium, similar to your everday table salt, which is why your sweat tastes salty. A bit of sweating is good for the body and keeps it from overheating. However, your blood and tissues are sacrificing the water and electrolytes out of their own stores, which throws their systems out of balance. Such loss of water, termed dehydration, can lead to thirst, dry mouth, saggy skin, headache, fainting, and several other unpleasant symptoms.

Besides dehydration, another problem we face is overexposure to the sun’s heat. This leads to heat exhaustion (headache, nausea, fatigue, faintness, and a great deal of sweating), the more serious heat stroke (headache, nausea and vomiting, no sweating), and prickly heat (a rash due to the inflammation of sweat glands after long periods of exposure to high temperatures).

In order to avoid all these possible consequences, we drink a lot of water and take salt tablets when we feel weak and overheated. Unfortunately, as the temperatures seem to rise day by day, we’re finding it very difficult to cycle during the hottest parts of the trip (between 11 a.m. and 3 p.m.). For this reason, we will try something new tomorrow: cycling from dawn until 11 a.m., and then again from 4 p.m. until sunset. In between, we’ll sit in whatever shade we can find, drink gallons of water, and write these updates to you!

Git

Today we met with a new nemesis: spinifex. Spinifex is
a hardy grass, adapted to the poorest, driest, and
least nutritious soils in Australia. It’s the single
most common type of vegetation in Australia, covering
almost one-fourth of the entire continent!

There are thirty different species of spinifex, but
all share a common characteristic: they grow as close
clumps of blades, fanning out into all directions and
forming a hemispherical “hummock.” The roots grow in
two directions, first horizontally away from the plant
and then vertically down, in order to reach both
surface rainwater and deeper ground water. The heart
of a spinifex clump makes good shelter for snakes,
lizards, and small mammals. Even when the temperature
outside climbs to forty degrees Celsius, the heart
stays cool and is an excellent place for wildlife to
escape the heat.

As a young grass, spinifex has flat leaves. During
this time, when pores (also called stomates) in the
leaves release drops of water, the harsh sun quickly
causes the water to evaporate. During its first dry
season, however, spinifex leaves curl inward, creating
a hollow tube. This shape keeps the water droplets
from evaporating. These hollow rods are needle-sharp
and very strong, thanks to the presence of silicon
granules (called phytoliths) in their outer skin. A
grazing animal (or uncoordinated Expedition biker)
learns quickly to steer clear of these plants, or risk
having its skin punctured. The type of spinifex we’ve
run into today is the Weeping Spinifex, undoubtedly
named not only for its shape, but also for its effect
on its victims!

Git

Since we are diurnal animals (we are awake during the day and sleep at night), during the day we need to be able to see many things about an object: its colours, textures, and contours. At night, though, our eyes don’t need to function as well. In order to see in these two different ways, the eye uses structures called light receptors. These receptors are located on a very thin sheet of tissue, called the retina, located at the back of our eyeball. Light enters the eye through the lens and hits the receptors on the retina. The retina then sends the light via the optic nerve to the brain, where the information is processed.

There are two types of receptors, performing two different functions. The first type, cones, are sensitive to light and colour, and are used mostly for day vision. The other type are rods, which are sensitive to dim light but not to colour. During the day the eyes mostly use cones, so in daylight we see colours. At night, though, the eye uses mostly rods. For this reason we don’t see colours at night very well.

The use of rods and cones has a couple of interesting consequences. At the centre of the retina is a spot called the fovea, which contains only cones. When you focus on an object, that object lands on the fovea, while everything around the object lands on the rest of the retina. Since the fovea contains cones, which are useful for seeing in the daytime, any object that lands on the fovea at night will not be seen. So, if you stare directly at a star in the sky, the image will land on the fovea and you won’t be able to see it very well. If you look just beside the star, however, the star’s image won’t land directly on the fovea. It lands instead in a region around the fovea, which contains rods (remember that rods work well in dim light). You will thus be able to see the star better. Try this when you get home tonight!

Can you think of any animals which need to see well at night? What are the special features of their eyes that help them to do this?

Git

Science – camels

In order for camels to survive in the desert, they must have ways of coping with the desert heat. These coping mechanisms are called ‘adaptations,’ and they’ve developed over many thousands of years. For example, camels have learned to face the sun when lying down, causing less of the body to be exposed. In this way, the body catches less sun and doesn’t heat up as fast. Unlike humans, camels’ bodies can withstand large differences in temperature: the body becomes very hot during the day and cools off at night. Because of this, they’ll roam about for food during the cool night, and during the day spend most of their time resting and chewing their cud.

Camels don’t need nearly as much water as we do to survive. While a person can lose only 14-15% of the water in their bodies, a camel can lose as much as 35%. Of course, all animals need access to some water, but free water can be hard to find in a desert. Camels are adapted to get almost all the water they need from the plants they eat, if other water isn’t available. Eating green plants alone, a camel can often survive for weeks without drinking, especially in winter when it’s not as hot. If they do find a water source, they can drink huge amounts of water in one day: up to 200 liters!! They can do this thanks to another adaptation, a substance in their blood that allows their bodies to absorb moisture much faster than our bodies can. They also save water in other ways. For example, any moisture that collects in their noses via condensation ends up running down a groove back into their mouths. And when they urinate, the urine runs down their back legs, cooling the rear of their bodies.

Another adaptation to the desert environment is the foot. It has only two toes, with a very large surface area underneath, which is perfect for walking on soft sand. The foot doesn’t have a hoof; it has a large callus pad under it, nearly one centimeter thick. If the camel carries too heavy a load, or if it has to walk in rocky areas, the pad can come off and take months to grow back. All the surfaces of the body that come in contact with the hot sand in fact have these calluses. They keep the camel’s skin from being burned by the hot sand.

Suggested learning activities: identify another animal that has adapted successfully to living in the desert. List down the physiological characteristics that make this possible.

Identify an animal in your local area that displays successful adaptation characteristics to its local environment.

Git

The snake that Mike saw today was a Yellow-faced Whipsnake. Whipsnakes are slender, fast moving and active during the day. They have large eyes on which they rely on a great deal as they bulk of their diet consists of lizards that are active during the day. So why are the daylight hours so critical?

One clue lies in the fact that Mike stumbled across the snake while it was basking in the light of the mineshaft. Being reptiles, snakes are ‘ectotherms’ meaning they rely on external heat sources to maintain a constant body temperature. Having no internal mechanisms to generate heat – like mammals do – they must seek out warmth. This why snakes are often referred to as ‘cold-blooded’.

It’s a good thing the snake was still relatively cold and inactive when Mike found it. Otherwise the story might have turned out very differently!

Suggested learning activities: find out how mammals regulate their body heat and list the key differences to ‘ectotherms’.

jason

2001 August 27, Monday. West of Atula Station.

The stick insect we were lucky enough to see today was the most incredible example of camouflage which many of us had ever seen. Jason was about to brush a stem of spinifex grass off his Camelbak, when it shied away from his hand, and crouched again to sit perfectly still just centimetres away, looking just as much like the surrounding grassland as it had done before.

A close inspection revealed the simple form – four legs and a long body like a slender piece of straw. After staring in amazement for some minutes, we looked at the landscape around us, imagining the thousands of creatures which could be right in front of us, though blended with their surroundings so perfectly as to be completely hidden from our view. As we were attempting to discover which end was the front, he revealed another pair of legs, (for a total of six) which we had not been able to see earlier despite the thorough scrutiny he had undergone.

Because of the extreme scarcity of food in arid regions, predators do not give their prey second chances, and the best defence for palatable creatures such as our remarkable little friend, is to not be seen by them in the first instance – by camouflage.

We have seen a wonderful example of this in the serrated skin of the lizards which populate the desert. A central bearded dragon sitting on a rough textured log, as long as he keeps still, is safe from the kites and other birds of prey which might make a meal of him. Likewise, a burrowing skink could easily pass for a eucalypt twig, lying motionless in the sand collecting energy from the sun.

A large portion of desert life lies dormant for most of the year (and often for several years) until times of rain animate the countryside. Those animals which lie incompletely concealed under the earth, need camouflage to remain undetected while they are in the dormant state. Some species of frogs demonstrate this well by matching the their skin to the colour and pattern of the soil in which they live.

What animals can you think of which hide using camouflage? How many can you think of in the country in which you live? What techniques do other animals use to protect themselves from predators, if they do not blend well with their surroundings? How could you find an animal which is hiding using camouflage?

bel

CONDENSATION

Because termites largely populate quite dry, inhospitable regions, adaptation to deal with the little water available has been essential for them to succeed as colonists of these marginal areas.

Check out the maths update to find out why termites are so susceptible to water loss, and how artificially raising the humidity inside their mounds helps to overcome this problem.

Some termites can also create water in their mounds by CONDENSATION. Coptotermes brunneus, found in the northwest of Australia, builds huge 2m high mounds sealed on the outside with impermeable clay. The upper sections consist of bulbous cavities connected by vertical tunnels to live-in chambers underground. Metabolic water from these chambers will rise as water vapour to the top of the mound and condense back into water once exposed to the outer layer which is quite susceptible to temperature change during the nights (in desert regions the temperature can drop by 12 degrees Celcius). This water will then drain into the base of the upper cavities ready to be collected by the termites.

Suggested learning activities: think of an experiment that demonstrates the process of CONDENSATION that occurs inside the mound of the Coptotermes brunneus termite. Suggested examples are:
- tying a plastic bag around a leafy branch overnight and seeing how much water is collected.
- blowing onto a glass or mirrored surface (the colder the better)

The Great Artesian Basin was formed about 130 million years ago, by a sheet of quartz over a shelf underground. The Great Dividing Range was formed 1000 years earlier, when the rains came the mountains ran rivers off them. All the water on the eastern side ended up in the ocean where as the water on the western side had no-where to go and just sat and sank into the earth. This process occurs every wet season; and has been occurring ever since the Dividing Range was formed and heavy rain has come down.

Over the years the Basin formed a constant underground current that heads from the Great Divide toward the western plains. This current pushes water up above the ground, forming springs, creating water sources for living organisms above the ground as well as below. Hot springs can be found within the Basin area, and are warmed by either heat absorbed by the ground, or by molten rock / volcanic activity within the earth.

Feed your children wheat. Joshua.

During our cycling expedition we have been pushing a lot of kilometres and due to this we have found that we need rest. We are now in Mount Isa, staying on Greg and Margaret’s property. Margaret is a physiotherapist, and I asked her about how important rest is. She threw me loads of facts about how we should be eating and what we should be eating; how we should be sleeping and general signs of over training. Some of these are your pee is yellow, this is a major sign that you are not getting enough water into your body, your pee should be clear. Loss of appetite and loss of body weight (3%) is when you should start getting worried. Some physical signs are heavy legs, sore anything and generally tired. Some psychological stress can be low motivation, low concentration, low self-confidence, increased aggressiveness. Other signs of over training can be poor sleeping patterns and poor eating routines.

For eating we have a fairly stable diet and although it may not be first class restaurant food, it does get us by. I found some interesting information from Margaret that foods have just recently been researched into to find some simple carbohydrates like potatoes and pasta may not be as heavy-duty endurance foods as we were led to believe. These sources in the foods are called G.I foods and they are rated from 1 to 100, 1 being the highest in the G.I food group. Some pastas are not as good for you as some such as normal pasta that you may pay the same price doesn’t have as high G.I as Basmati or Doongarra pastas, these both have rather high G.Is.

G.I food supplements are important for all endurance athletes, as when someone hits “the wall” they have simply run out of G.I foods. G.I foods can only be stored for 24 hours or there about so everyday you must supplement them as much as possible. Some foods that are high in G.I are corn, peas, sweet potato, Pink potato with apples and oranges.

Some ways of realising that you are over training can be recording sleep and quality, recognising that you are feeling constantly tired and recording your heart rate. So now you guys out there reading this won’t have any excuses for over training.

Feed your children wheat. Joshua.

With Jim now gone, our small group of eight has just been reduced to just seven, of whom one has to drive the support vehicle while John is away. This leaves only seven people cycling during the day. The effects of a member leaving the team can alter the group dynamic quite considerably, as can someone joining. The same happens when a new species is either removed or introduced into a (relatively) stable ecosystem.

Plants and animals are commonly being introduced into foreign communities. For example, the fire ant was introduced into Brisbane earlier this year, liked the climate and quickly populated the region quickly. Slimily the Cane toad was introduced into south Cairns in the mid 1970s to exterminate the cane beetle that lived on top of the sugar cane. Obviously the toad couldn’t catch the beetle and also became a pest. The cane toad is now a major pest in North Queensland. Native animals are still suffering the side effects.

Occasionally the DPI (Department of Primary Industries) will come across plants and animals that can be placed into another environment, for the better of the community.

Suggested learning activities: what animals or plants are in your community that have been introduced? What effects did they have on the environment? Are they good or bad? Explain your answers.

Feed your children wheat. Joshua

2001 August 14, Tuesday. 45 kilometers North of Julia Creek.

Today, the Gulf Savannah Grassland, we have been passing through sunk away into a flood plain. At present the sand is dry as any country we have seen thus far, and tufted grass grows evenly throughout the broad plain. Clues to the activity in the area lie in the pockmarked texture of the earth, made from cattle hooves at a time when the ground was shallowly submerged for some months during the wet season.
Such a change in water levels compared to the surrounding area has the potential to improve soil content, by encouraging the production of organic matter, which decomposes into valuable soil. However, as long as the climate remains as harsh as it is, with extreme wet summers and scorching winters, vegetation cannot thrive. Tall shade trees are unable to grow because their roots would be rotted out in their first wet season. Accordingly, neither will the shrubs and smaller plants which thrive in the shelter they offer.

If soil from the plain was taken to a moderate climate, lush plants could be grown in it. With conditions as they are, tough brown grass is intercepted only by stunted, prickly shrubs – on average less than ten per kilometre. Because of the sandy top to the ground, it dries out quickly, and herbaceous plants which might grow as the wet receded, would be parched to dust, leaving no trace after the first week of heat.

What do plants need water, earth, and light for? What can happen to a plant or tree which has too much of each of these?

bel

2001 August 6, Monday. Pinnacle Springs Station.

It’s difficult to convey the extreme intensity of the tropical Australian sun to anyone who has not experienced it. When you’re out here on a bicycle, with only what you can carry on your back, your complete reliance on water makes you feel very small. The thought of our supplies expiring could turn us into savages in no time flat, as we have already had glimpses of within the team.

Damage to the ozone layer, the protective barrier shielding our earth from harsh ultra-violet light, is the fundamental cause of the severity of the sun today, and has developed largely through human insensitivity, and abuse of resources.

Ultra-violet light, unfiltered by sufficient ozone, is not only uncomfortable, but also dangerous. It can be divided into three types of rays:
UV A: which is responsible for aging of both skin and eyes;
UV B: which causes burning; and
UV C: which is carcinogenic, or cancer causing.

While people are now mostly well informed about the danger of exposing unprotected skin to midday light, the beach bathers of yesterday are paying the price for their fun in the sun. Damaged eyes and skin cancers are the most common results of a life spent enjoying the warmth of the summer sun in Australia.

One Australian icon which has helped to protect outdoor workers and players from this natural hazard is the Akubra hat. As we cycled into Pinnacle Springs Cattle Station yesterday, and were greeted by Laura and Emma Kruckow, one of the first things we noticed was their headwear. Both sisters wore broad brimmed white Akubra hats which seemed almost bigger than the girls themselves.

Most country Australians own at least one Akubra, and they come in as many shapes, sizes, and colors as the characters who wear them. At rural shows and stock sales, the broad range of hats on display is an exhibition in itself. Travelers collect pins from all over the country and sport them around the crowns of their hats. Some people wear one hat for twenty or thirty years, dragging it through dust and grease, sitting on it, and wearing holes in it, until it develops a character inseparable from its wearer.

Suggested learning activity: do you need to guard yourself from the sun where you live? How do you protect yourself when outdoors or in the water? Do you or someone in your family have a special hat? How can we help to save our ozone layer from damage by chloroflurocarbons?

bel

The use of steam engines in gold mining was very important and played a major role in the machinery being used during that time. Here are some of the uses for steam engines!…

The primary use for steam engines during the mining time in and around Maytown was to power the winches that were used to haul gear up out of the sometimes, 600 ft. deep mine shafts and to power the crushing and separating of raw ore in the mills. The way steam was used was as a way to turn pistons, very similar to what gasoline does in your car when it combusts, or explodes. Once pistons could be moved, they in turn powered belts and different levers that moved rocks in and out of various separating areas. One area included a big metal dish that had a giant metal ball spinning in it that crushed ore. Once the ore was crushed, it was separated in bath of mercury. Another area that the steam powered was the turning of a wheel that lifted raw rocks and rubble out of extremely deep mine shafts. The power it took to lift the weight of all those rocks must have been incredible.

The water, which creates the steam, was all heated by wood. Because of this, a cleared area of no trees with a radius of about 20 miles was created around Maytown. All of the trees that we see while riding are new growth, or second growth.
As you can see, the power of steam engines in the mining times was awesome, both mechanically, and environmentally!

By, Crister

The process of extracting gold from the Palmer River gold fields of the 1870s was no easy task. As much as twelve tons of machinery was needed to extract the ore from the rocks in each location.

Sites selected for the machinery were on the reefs where the greatest amount of work was being done. Miners’ accounts recall, “The two principal mines are the Ida and the Queen of the North. They are by the employment of labor quite capable to give full employment to two machines now in transit.”

The road from Cooktown to Maytown was 150 miles of the roughest country in the north. Often, machinery had to be dismantled to be lowered and raised by block and tackle over the rough terrain. It cost more than 800 pounds to bring the first ore crushing machinery from Cooktown to the Palmer.

Depths in mines could reach 120 feet to extract the ore. The greatest average thickness was about two feet carrying gold throughout. The best blocks of stone were obtained from the deepest levels.

The arrival of Messrs Edwards and Co’s machine caused great excitement among the miners. It was a ten stamper, six hundred weight, driven by a twelve horsepower engine and capable of averaging ninety tons a week. It was installed on the banks of the Palmer River. Crushing batteries were erected on the bank of a river whenever possible, as a good supply of water was essential for the crushing of ore. Huge bed logs were needed for the battery and the steam engine that drove it. Trees were felled, then floated down river, guided by strong swimmers to keep them clear of debris.

As the Wet season approached, the lack of feed for teams used to cart the ore to the stampers became a problem. Animals died due to starvation. The machines were ready to begin crushing in December. There were more than sixteen hundred tons of ore waiting to be treated.

Despite the hardships, enthusiasm ran rampant. Around Maytown, rich quartz specimens were being shown around. Early results had fulfilled expectations. From the Queen of the North, 110 tons of quartz had returned 915 ounces of smelted gold, a little over eight ounces ore per ton. The Maytown reefs were about to come into their own!

Suggested activities: Research mining techniques, past and present, in your area. Determine how machinery plays a role in the extraction of the ore in the mining process.

Tiger Creek to Lake Emma
67 km

The x360 team pulled out of our rainforest camp a bit later than we wanted, about 8:45am. The road surface was hard-packed red soil for the first hour or so, until we turned up the Battle Camp Road towards the Normanby River. Crister, who was leading the team for the day with the topographical maps and GPS, let us know that the next ten kms to the river would lead us through a small range of mountains. No worries, hills aren’t bad, we thought. But the road surface was.

At the base of the first hill the road surface changed to loose sand and soil. There were a number of Land Cruisers, Land Rovers and other outback-equipped vehicles using the track, and we entered a 40km stretch of alternating sand, a bit of good packed surface, and the cyclist’s lament, corrugation/washboard/bump-after-bump from here to forever.

Those of you who live where there are dirt roads on loose soil know what we rode on today. We couldn’t go fast, like the vehicles, and ride along the top of the ridges. If you go too slowly your rear end and spine take quite a beating. Out mountain bikes took quite a beating, as did our wrists, necks and legs.

So, why do roads develop bumpy, or corrugated surfaces, like road waves, where the same type of bump appears over and over? We don’t know exactly, but here are some thoughts. How about waves on the sea: they’re caused by repeated wind action. How about sand on the bottom of the sea, where currents make ripples on the sand bottom. Cirrus clouds before a storm form waves in the sky. And when car tires move along a road the repeated pattern of ‘road waves’ is formed.

But again, why? We think it is related to a branch of mathematics and science called “Chaos Theory,” where random events form a pattern through repetition. Each tire hits a small bump. The tire is spinning; it has energy transferred from the drive shaft. It bounces up a bit, over the bump and lands, spinning, throwing some sand backwards. It hits the next bump, over, hits, spins and throws more sand backwards. Each time a car comes by, the bumps get a little bigger, more are formed, and eventually there are miles of evenly spaced bumps to bedevil cyclists like us.

An observation: most corrugation is on uphills. Most, but not all. Today we had washboards appear on dead-flat stretches of road. So, a question: to what extent is the creation of corrugation dependent on road surface?

So, somewhere on a completely flat surface (a newly-graded road, calm sea, etc.) there had to appear the first bump, the first wave. How? Why? It is chaotic, a pattern appearing out of randomness.

If you’re interested, check out this website for further amazing thoughts on corrugation/patterns/washboard and Chaos: search for “Treebeard’s Stumpers” a great list of Science related questions and other oddities from Mark Kummel, a Science teacher and naturalist from California.

So, we’re all a little sore from the beatings we endured today on the corrugated Battle Camp Road, but we had time to observe our surroundings and think about Chaos Theory. What a fine day it was!