Australia Lesson Activities - Science

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

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

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

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

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.

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.

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)

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

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