Radio Solutions Questions from 4BC

Last week we had some interesting questions about the habits of our animals!

Where do birds sleep at night?

Birds tend to sleep in the same areas they inhabit during the day. They usually find a safe place and if possible they huddle together with other birds. Water birds will often sleep whilst floating on water or standing on one leg on the edge of a pond and other birds will find shelter in trees with thick foliage.

Some birds can even sleep whilst flying ... true! Birds can sleep with one eye open and this is called unihemispheric sleep and it means that half the brain is asleep and the other half is awake. This gives them the ability to watch for enemies and still catch up on sleep – and this is what allows them to fly whilst sleeping.

For those birds who do stop and rest to sleep, they fluff up their feathers to provide insulation and turn their head and rest it on their back. This gives their neck muscles a rest.

Have you ever wondered why birds don’t fall off their perch when sleeping? It is because of a special muscle around their knee joint. When they squat down and slightly bend their leg, this muscle pulls the claw muscles tight and helps them clasp around the perch. A bird cannot move his foot until he has straightened his legs.


Ashley from Belmont State School asked how he could tell whether his baby grey cockatiels are boys or girls?

The sex of normal grey cockatiels can be easily determined once the adult plumage is through at about 6 months. Unfortunately other than having expensive blood/dna tests done by a bird vet it is impossible to tell the sex of a cockatiel before this time.

However, once the adult feathers are through, depending on the colour variety the male usually has a brighter yellow face, whereas the female only has traces of yellow around the beak eyes and forehead. The male's tail feathers will be a solid grey color with no striping, but the female's will remain striped and they will have yellow spots on the underside of their flight feathers. See the picture here thanks to http://www.birdhealth.com.au/


Lilly asked, why do frogs croak more when it is raining?

In most frog species it is only the males who croak and they mostly croak to attract female frogs for mating and to warn other males away from their territory. Many tree frog species let out a “rain call” when rain is coming to advertise the fact they are there ready and waiting and that the weather conditions are perfect for mating – lots of water for egg laying and nice moist conditions outside the pond. Very romantic!

Today's Radio Solution from 4BC

6 February 2008

Today we had a question from Melissa Wu, Australia's youngest National Diving Champion, who is fitting in her school work around her gruelling 6 hour per day training schedule. Melissa had a tricky question in relation to her school work.

She wanted to know if Dopamine makes Parkinson's disease more active or less active?

Parkinson's Disease occurs when there is a lack of Dopamine in a specific part of the brain. It happens when there is a destruction of brain cells in the substantia nigra region which is the area responsible for many types of muscular movement. The substantia nigra controls muscular movements by releasing a neurotransmiter called dopamine which is needed to carry nerve messages from one brain cell to another resulting in smooth controlled movements. Without Dopamine the brain has abnormal firing patterns causing the jerky uncontrolled movements of Parkinsons.

There is also evidence that a lack of Dopamine is present in people with ADD. It seems that Dopamine's main role is to slow things down and keep things calm and controlled.

Today's Radio Solution from 4BC

4 February 2008

Ross from Cannon Hill had a great question for us today on 4BC about Helium Gas.

Why does your vioce sound higher when you have inhaled helium gas?

When we talk, sound is produced by passing air over our vocal cords (flaps of tissue in our throats) causing them to vibrate thus producing soundwaves. The speed at which the sound waves are generated is what determines the pitch. Normally, we breathe air which is a mixture of gases containing mainly nitrogen and some oxygen and is heavier than helium. Sound waves through air moves at a fairly constant 350 metres per second.

Helium is less dense than the air we normally breathe and this means that sound waves travel through it much faster than usual (around 900 metres per second). This means that if you increase the speed of the sound waves, the frequency also has to go up and this means that our voices sound much higher than usual.

Therefore the faster the sound waves produced the higher the pitch. There are a lot of videos on You Tube of people inhaling helium which are quite funny. Remember though - whilst inhaling helium from a balloon won't necessarily kill you, it can make you dizzy and you could fall and hurt yourself. As well ... NEVER EVER ... inhale helium from the cannister as this can kill you due to the pressure behind the helium.

1 February 2008

Morgan had a great question today about the weight of earth.

Does Earth get heavier with the increasing population and infrastructure associate with it?

It does get heavier. Every year, many tons of microdebris from space land on earth, approximately 40,000 tonnes, but it's really miniscule amount compared to the size of the earth and will never throw the earth off its axis.

Increasing population doesn't really change the weight of the earth – as people die new babies are born (which weigh significantly less than the people who die) as well when people die their bodies are cremated or decompose with equates to very little weight. Admittedly the population today is much more than that of hundreds of years ago, however the extra people balance out the shortfall below.

In regards to infrastructure the materials used to build are already here on earth just in different forms – so it’s really stuff that is already here just being moved around. This tends to reduce because events like fires destroy vegetation and buildings reducing it to nothing.

Today's Radio Solution from 4BC

31 January 2008

Kelsey asked us a great question today about cloud seeding. It produced a fairly long answer though - hope you enjoy it!

How does cloud seeding work and how do they actually know when it has worked?

First we need to know how rain starts. It starts as tiny droplets of water suspended in clouds. Then the droplets clump together into bigger drops (or freeze together into bigger crystals). Once the drops or crystals are big and heavy enough, they fall out of the sky. The frozen drops can melt on the way down, becoming rain, or they can fall to the ground as snow or hail.

Cloud seeding aims to jump-start this process by helping droplets to clump or freeze together when they otherwise wouldn't. To do this they usually sprinkle silver iodide from above by plane. Silver iodide (AgI) is a chemical compound that can be used in photography, as an antiseptic in medicine and for rainmaking and cloud seeding. Pictured is a Cessna Plane with cloud seeding equipment fixed to it.

To get the best from cloud seeding, weather forecasting techniques are used to detect suitable clouds in the location and target area as it is only effective in a limited number of weather conditions. A cloud must be deep enough and of a suitable temperature (between -10 and -12 degrees) and the wind must also be below a certain speed – mountainous areas seem to be the best. The silver iodide, which has a cyrstalline structure similar to that of ice, speeds up the freezing

In some places they use dry ice or propane as the gas expansion cools the air to such an extent that ice crystals can form spontaneously from the vapour phase and unlike silver iodide, the clouds don’t need ice crystals in them already.

It is difficult to measure just how much rain would have occurred had the cloud not been "seeded". The cloud did have rain in it and whether or not the seeding produced more rain is really not known. It may speed up the rain process though. However, there is credible scientific evidence for the effectiveness of winter cloud seeding over mountains (to produce snow) than there is for seeding warm-season cumuliform (convective) clouds.

The most successful seeding in Australia has been carried out in Tasmania around the Hydro Water scheme area. The perfect cloud which has been seeded should take 30 minutes to precipitate.

There have been concerns about the long term environmental effects of using silver iodide crystals and the rain containing this chemical can be absorbed by animals, plants and collect in catchment areas. The effects of this are still being debated. Not everyone is for cloud seeding as some scientists believe manipulating the natural pattern may impact on eco systems reliant on a certain amount of rain. Farmers downwind of cloud seeding events sometimes believe their rain is being stolen by seeded clouds.

In Beijing they fire silver iodide rockets into the sky where rain is desired. They plan to use cloud seeding before the Olympic Games to help clear air pollution.

Today's Radio Solution from 4BC

30 January 2008

Today we had another great question on 4BC. This one was from Riley who goes to Guardian Angels School at Wynnum.

She asked - are the colours of a rainbow always the same and if so why?

Well to answer this we need to know a few facts about how rainbows are made.
The rainbow's appearance is caused by dispersion of sunlight as it goes through raindrops. The light is first refracted as it enters the surface of the raindrop, reflected off the back of the drop, and again refracted as it leaves the drop. The overall effect is that the incoming light is reflected back over a wide range of angles, with the most intense light at an angle of 40°–42°.

The water droplets in the air act like tiny prisms. The "white" light we see is actually made up of a combination of different colors so when the light passes thru these tiny prism droplets at the proper angle it breaks the white light into its basic color components (its color spectrum).

What makes rainbows the colours they are and in the same order is because angle of deviation is different for the two colors at either end of the rainbow because blue/violet coloured light is bent or refracted more than is the red light. The red light is refracted at around 42 degrees and we see the blue light on the inner part of the arc because we are looking along a different line of sight that has a smaller angle (40 degrees) for the blue. All the colours in between are at slightly smaller angles from the red. The diagram below from this informative site shows the red and blue light going through the water droplet.

To see a rainbow, one has to have rain and sunshine. A rainbow does not actually exist at a particular location in the sky. It is an optical illusion whose position depends on the observer's location and the position of the sun. The position of a rainbow in the sky is always in the opposite direction of the Sun with respect to the observer, and the interior is always slightly brighter than the exterior. The bow is centred on the shadow of the observer's head.

Unfortunately due to this the Irish leprechaun's secret hiding place for his pot of gold is usually said to be at the end of the rainbow. This place is impossible to reach, because the rainbow is an optical effect which depends on the location of the viewer. When walking towards the end of a rainbow, it will move further away.

Today's Radio Solution from 4BC

29 January 2008

Today on 4BC we had a great question from Hayley from Mt Alvernia College at Kedron.

Hayley asked why her white cat has two different coloured eyes?

It is actually a feline form of heterochromia and believe it or not, it does occur in humans as well as some animals. Some famous humans who have this condition are Alexandra The Great, Dan Akryod, Jane Seymour and Christopher Walken. On further research it seems that whilst David Bowie's eyes may appear to be different colours, it is because he has a permanently dilated (enlarged) pupil which makes his blue eye look green or brown depending on the light, and not heterochromia.

Now back to white cats. In cats, the odd-eyed colouring is caused by one of two genes:

1. The dominant white gene, which actually has the ability to mask any other colour genes and turns a cat completely white, or
2. The white spotting gene, which is the gene responsible for bicolour cats - white being one of the colours.

The white or white spotting gene has the ability to prevent pigment granules from reaching one eye during development, resulting in a cat with one blue eye and one green, orange or yellow eye. This rare eye colouring is most commonly found in white cats, although it can be found in any coloured cat in which the white spotting gene is present.

As all cats are blue-eyed as kittens, the differences in an odd-eyed kitten's eye colour might not be noticeable other than they have a different shade of blue in one eye, which can only be picked up on very close inspection. The colour of the odd eye changes over a period of months, for example, from blue to green to yellow, until it reaches its final, adult colour.

There is a common misconception out there that all odd-eyed white cats are born deaf in one ear. This is not true, as about 60%–70% of odd-eyed white cats can hear. White cats with one or two blue eyes do, however, have a higher incidence of genetic deafness, with the white gene occasionally causing the degeneration of the cochlea, beginning a few days after birth.

Tips and Tricks

Tip #3

When using Google, did you know that behind the Google Home page are stacks of other useful search tools? On the top left hand side where your options for images etc are, choose the last option "more" and then select "even more". This opens up a world of search help tools. There are plenty of options here, but to find even more scroll to the bottom and select "Web Search Features". My favourite is Q&A.

Have a look around - there is a lot more to Google than meets the eye!

From Cows to Wedding Rings

What happens to cows that aren’t milked. Do they swell up and get mastitis?
Dairy cows have been selectively bred over the years so that they produce 20 times more milk than their calves need. Dairy cows usually have a calf each year in order to produce milk. Cows, like humans, need to have a baby to produce milk.

However, cows used to breed beef cattle produce just the right amount of milk for their calves and like wild cows, they have tiny udders, not the huge ones you see on dairy cows. Like humans, once the calf doesn’t require as much milk the milk supply starts to dwindle. They don't usually have any problems, but Dairy cows are susceptible to Mastitis due to the large volumes of milk they produce.

Why is the wedding ring worn on the 2nd last finger on the left hand?

There are many theories as to why this particular finger came to symbolize marriage.

Both the ancient Romans and Egyptians believed that a vein - called the vena amoris in Latin - ran directly from that finger to the heart. Science has since disproved that theory, but it is still romantic to think that our wedding rings are on a direct path to our hearts.

In medieval England, a bridegroom would slide the ring part way up his bride's thumb, index and middle finger, saying "In the name of the father, the son, and the holy ghost" as he passed each one. He then put the ring on the next available finger - the third finger of the left hand. This practice was finally formalized in the 1500's when Henry VIII's son authored The Book of Common Prayer, which gives English modern Protestant wedding vows and decrees on which finger our wedding rings should go.

However, in some parts of continental Europe it is and always has been worn on the right.