This is an article from Curious Kids, a series aimed at children. The Conversation is asking kids to send in questions they’d like an expert to answer. All questions are welcome – serious, weird or wacky!

Who made the ABC song? – Hendrix, age 6, Dunsborough, Western Australia.

A common answer to this question is that the ABC song was first copyrighted under the title The Schoolmaster in 1834 by an American man named Charles Bradlee. You can see the original sheet music and lyrics here.

But the history of this famous song goes back a little further than that. Nobody knows exactly who invented this tune, but we have some clues about how it developed and became popular over time.

The ABC song uses the same tune as Twinkle Twinkle Little Star, and it’s similar to Baa Baa Black Sheep. (Try humming each one to check for yourself.)

The oldest published version of the tune is from 1761, but we don’t know who wrote it and it didn’t have any words.

The Twinkle Twinkle Little Star words were written by an English poet called Jane Taylor in 1806.

The tune has also been used by lots of different composers as a basis for their pieces - even a very famous classical music composer called Wolfgang Amadeus Mozart. Mozart wrote Ah, vous dirai-je, Maman (which means “Ah, Mother, if I could tell you” in English) in 1785. It sounds a lot like the ABC song, don’t you think?

When the ABC song first became popular, not very many children went to school. That meant that most people never learned to read and write. Over time, as it became more important to learn to read and write, more and more children learned the song when they were young to help them to remember the letters of the alphabet.

Another question that might be worth thinking about is why we sing the alphabet song at all. It has to do with how we learn.

Children have always learnt things from their parents and grandparents. Because most people didn’t read or write they weren’t written down, so it was really important to remember them. Groups of people in different places had their own songs to tell stories and pass down their history from one generation to the next.

Because of the way our brains work, we can remember songs and rhymes much more easily. The reasons are a bit complicated, but it’s partly because we pay more attention to the timing and speed of the sounds. When we do this, we use more of our brain at the same time, which means we remember it better.

So we don’t really know exactly who wrote the ABC song, but we know that most children who learn to read and write English now sing this song to help them remember the letters.

Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to us. They can:

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Rachael Dwyer, Lecturer in Music Education and Teaching, University of the Sunshine Coast

This article is republished from The Conversation under a Creative Commons license. Read the original article.

This is an article from Curious Kids, a series for children. The Conversation is asking kids to send in questions they’d like an expert to answer. All questions are welcome – serious, weird or wacky!

I just had a baby tooth fall out. Do cats and dogs lose baby teeth like people do? – George Mulhern, aged 7 (nearly 8), Brunswick.

Dear George,

The short answer is yes.

Like young humans, puppies and kittens have baby teeth. We call them “deciduous” or temporary teeth.

Puppies and kittens are born without teeth but have a full set of baby teeth by the time they are two months old. These fall out and are replaced with adult teeth by the time the puppies and kittens are about six months old.

Most of the time you won’t be able to tell if a puppy or kitten’s tooth falls out. Often they fall out in food, or your pet might even swallow them.

Grown-up humans normally have 32 teeth (unless they lose some or have some extra ones). Puppies have 28 temporary teeth, and when they grow up they have 42 teeth. Kittens have 26 teeth, and when they grow up they have 30 teeth.

Their teeth are differently shaped to ours. Unlike us, dogs and cats have very long canine teeth, which look a bit like fangs.

The bit of the tooth you can see above the gum is called the crown. But each tooth has at least one root - a part extending below the gum. This can be as big as the crown, sometimes bigger.

Dentists and veterinarians do X-rays on their patients to see whether the tooth roots are healthy, or if there are extra roots, or whether teeth need to be removed.

They may be only temporary, but the baby teeth of puppies and kittens can be sharp, so I don’t recommend getting too close to have a look. Next time your pet goes to the vet for a check-up, the vet can carefully open your pet’s mouth and show you the teeth.

Sometimes a baby tooth does not fall out before the adult tooth starts to emerge. This means that two teeth are trying to squeeze into one space in the mouth. It can cause pain and other problems, like food getting stuck between the two teeth. That can lead to really stinky breath. So sometimes veterinarians need to remove these stubborn baby teeth.

Puppies and kittens don’t brush their own teeth. The best way to keep their teeth clean is to give them a healthy diet, as chewing helps to keep the teeth clean. Regular dental check-ups at the vet are also important. Some pets will let their owners clean their teeth, but this should only be done by a grown up. Not every dog and cat likes having their teeth cleaned.

They can’t use human toothpaste because they don’t know how to spit it out. Instead, there is special toothpaste made just for dogs and cats - and it comes in meaty flavours.

Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to us. They can:

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Please tell us your name, age and which city you live in. You can send an audio recording of your question too, if you want. Send as many questions as you like! We won’t be able to answer every question but we will do our best.

Anne Quain, Lecturer, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

This is an article from Curious Kids, a series for children. The Conversation is asking kids to send in questions they’d like an expert to answer. All questions are welcome – serious, weird or wacky!

Where does the oxygen come from in the International Space Station, and why don’t they run out of air? – The students of class 3E, Ferny Grove State School, Brisbane.

That’s a really good question. The short answer is the astronauts and cosmonauts (that means a Russian astronaut) bring oxygen from Earth, and they make oxygen by running electricity through water. This is called electrolysis.

The air and water on the Space Station all originally came from Earth. Astronauts and cosmonauts transport these vital supplies to the Space Station when they travel there on Soyuz capsules (a type of spacecraft). Astronauts and cosmonauts also receive supplies from uncrewed spaceships, such as the Russian Progress and American Dragon. Uncrewed means with no people on board.

But fresh supplies from Earth aren’t enough to sustain the Space Station. That means if you’re onboard the Space Station you are really, really into recycling.

The Space Station’s water recycling system produces pure drinking water from waste water, sweat and even urine. In the words of astronaut Douglas Wheelock, “Yesterday’s coffee is tomorrow’s coffee.”

Water, which is made of oxygen and hydrogen atoms bonded together, is also used to maintain oxygen supply on the International Space Station. Using a process called electrolysis, which involves running electricity through water, astronauts and cosmonauts are able to split the oxygen from the hydrogen.

By the way, do NOT try this at home. Water and electricity do not mix, normally, and it can be very dangerous to try.

Electricity is one thing on the Space Station that doesn’t come from Earth, as the Space Station’s vast solar panels convert sunlight into power.

But what’s done with the hydrogen that’s left over? Using some chemistry and smart thinking, they’re actually able to turn it back into water!

The hydrogen is combined with carbon dioxide (that the astronauts and cosmonauts breathe out) to produce water and methane. So now there’s some more water to drink, while the methane is simply waste that is blown out into space through special vents.

So if you get a chance to see the Space Station tonight, you can marvel at many things.

Marvel at a spaceship travelling more than seven kilometres every second. Marvel that you can see where people live 400 kilometres above the Earth. And marvel at recycling that keeps people alive in the harsh environment of space.

Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to us. You can:

* Email your question to curiouskids@theconversation.edu.au
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Please tell us your name, age and which city you live in. You can send an audio recording of your question too, if you want. Send as many questions as you like! We won’t be able to answer every question but we will do our best.

Michael J. I. Brown, Associate professor, Monash University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

This is an article from Curious Kids, a series for children. The Conversation is asking kids to send in questions they’d like an expert to answer. All questions are welcome – serious, weird or wacky!

Where does my poo go when I flush the toilet? Does it go into the ocean? – Clancy, age 4, Austinmer, NSW.

When you press the flush button, your wee, poo, toilet paper and water go down a pipe called a sewer. The toilet flushes the wastes down the sewer pipe. The sewer pipe from your house also collects and removes other wastes. This might be soapy water from baths and showers, or water left over from washing dishes and clothes. Together, all of these wastes are called “sewage”. The pipes they travel through are called “sewerage pipes”. People sometimes get “sewage” and “sewerage” mixed up.

The wastes from your house flow downhill. They join those from other homes and flow into bigger sewer pipes. Some of these pipes are bigger than a bus! If you live in a big city the wastes from thousands of people looks like a river of sewage.

The big sewer pipes take all the sewage to a place where it is treated. This place is called a sewage treatment plant. All towns and cities have these. They are like a big factory where any harmful materials are removed. This is a very important part of our city life.

Sewage contains lots of germs and if people come into contact with it, it can make them very sick. The treatment also removes things that people have flushed down the toilet. This includes things like toys, jewellery or even money. There are some things you should never flush down the toilet, like baby wipes – even if it says “flushable” on the packet – because they clump up and cause big problems for the sewerage system.

The sewage is cleaned in the treatment plant. This can take many days. It makes sure that harmful parts of the sewage are removed. Chemicals are added to kill as many germs as possible. Then the treated water is released into a local river or even the ocean. If you live near the coast your treated sewage probably goes into the ocean.

The treated sewage is cleaned to make sure that it does not cause environmental problems. This means that it should not harm the plants and fish that live in the river or ocean where it is released. If the sewage is not fully treated it can cause water pollution. It also should not make people sick if they swim in the river or ocean. Scientists test the water and the sewage wastes to make sure that it is OK.

Some treated sewage can be used to make energy or recycled to make water that can be used in factories or farms. Some countries, including parts of Australia, can even make water from treated sewage that is safe enough to drink. Singapore makes “recycled” drinking water out of treated sewage that is even purer than the level that the World Health Organisation (which is a group that makes a lot of suggestions about what’s healthy and what’s not) says is safe to drink.

Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to us. You can:

* Email your question to curiouskids@theconversation.edu.au
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Please tell us your name, age and which city you live in. You can send an audio recording of your question too, if you want. Send as many questions as you like! We won’t be able to answer every question but we will do our best.

Ian A. Wright, Senior Lecturer in Environmental Science, Western Sydney University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Curious Kids is a series for children. If you have a question you’d like an expert to answer, send it to curiouskids@theconversation.edu.au You might also like the podcast Imagine This, a co-production between ABC KIDS listen and The Conversation, based on Curious Kids.

How can penguins and polar bears stay warm in the freezing cold waters of Antarctica? - Riley, age 8, Clarksville, Tennessee USA.

Thanks for your question, Riley. The first thing I should probably say is that while a lot of people think polar bears and penguins live together, in fact they live at opposite ends of the Earth. Polar bears live in the northern hemisphere and penguins live in the southern hemisphere.

I’m a penguin researcher so I’m going to explain here how penguins can stay warm in Antarctica.

There are four species of penguins that live in Antarctica: emperors, gentoos, chinstraps, and Adélies.

All these penguins have special adaptations to keep them warm, but emperor penguins might be the most extreme birds in the world. These amazing animals dive up to 500 metres below the surface of the ocean to catch their prey, withstanding crushing pressures and water temperatures as low as -1.8°C.

But their most incredible feat takes place not in the ocean, but on the sea ice above it.

Surviving on the ice

Emperor penguin chicks must hatch in spring so they can be ready to go to sea during the warmest time of year. For this timing to work, emperors gather in large groups on sea ice to begin their breeding in April, lay their eggs in May, and then the males protect the eggs for four months throughout the harsh Antarctic winter.

It’s dark, windy, and cold. Air temperatures regularly fall below -30°C, and occasionally drop to -60°C during blizzards. These temperatures could easily kill a human in minutes. But emperor penguins endure it, to give their chicks the best start in life.

A body ‘too big’ for its head

Emperor penguins have four layers of overlapping feathers that provide excellent protection from wind, and thick layers of fat that trap heat inside the body.

Have you ever noticed that an emperor penguin’s body looks too big for its head and feet? This is another adaptation to keep them warm.

The first place that you feel cold is your hands and feet, because these parts are furthest from your main body and so lose heat easily.

This is the same for penguins, so they have evolved a small beak, small flippers, and small legs and feet, so that less heat can be lost from these areas.

They also have specially arranged veins and arteries in these body parts, which helps recycle their body warmth. For example, in their nasal passages (inside their noses), blood vessels are arranged so they can regain most of the heat that would be lost by breathing.

Huddle time

Male emperor penguins gather close together in big groups called “huddles” to minimise how much of their body surface is exposed to cold air while they are incubating eggs.

This can cut heat loss in half and keep penguins’ core temperature at about 37°C even while the air outside the huddle is below -30°C.

The biggest huddles ever observed had about 5,000 penguins! Penguins take turns to be on the outer edge of the huddle, protecting those on the inside from the wind.

Incredibly, during this four-month period of egg incubation the male penguins don’t eat anything and must rely on their existing fat stores. This long fast would be impossible unless they worked together.

Changing habitats

Emperor penguins are uniquely adapted to their Antarctic home. As temperatures rise and sea ice disappears, emperors will face new challenges. If it becomes too warm they will get heat-stressed, and if the sea ice vanishes they will have nowhere to breed. Sadly, these incredible animals may face extinction in the future. The best thing we can do for emperor penguins is to take action on climate change now.

Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to curiouskids@theconversation.edu.au Please tell us your name, age and which city you live in. We won’t be able to answer every question but we will do our best.

Jane Younger, Research Fellow, University of Bath

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Curious Kids is a series for children. Send your question to curiouskids@theconversation.edu.au. You might also like the podcast Imagine This, a co-production between ABC KIDS listen and The Conversation, based on Curious Kids.

How would the disappearance of anglerfish affect our environment? - Bella, age 6, Sydney.

As I am sure you know, anglerfish live deep in the ocean. The females have an enlarged fin overhanging their eyes and their mouth that acts as a lure – much like bait on a fishing line - and this explains their name. (“Angling” is a method of fishing.)

The fact is we understand very little about the deep sea and how its inhabitants, including anglerfish, will respond to change. In fact, more people have walked on the Moon than have been to the bottom of the ocean.

But I will do my best to answer your question.

The food web

Close your eyes and imagine a spider’s web. All parts of it are connected, and if a bug gets tangled in one part, it can cause a completely different part of the web to wobble or break.

It helps to remember that all species are interconnected via something called the “food web”. The food web is not a real web like a spider’s web. It’s just a way of thinking about how species are connected to each other. Basically, the food web tells us who eats whom.

If you make a change to one part of the food web, that can have an ripple effect that can cause changes on another part of the web.

Less of one animal can mean more of another

Anglerfish usually eat small fish, as well as relatives of shrimp.

It is likely that if all the anglerfish in the ocean disappeared, their prey would explode in number and another predator would then “step in” to replace them.

And any species that likes to eat the anglerfish would have to start eating another species instead – or risk dying out.

At the height of the whaling industry, about 100 years ago, whales nearly disappeared. That meant that the number of krill (the tiny animals that whales eat) exploded, providing a feast for other animals that also eat krill – such as seals. That is how a food web works.

Weird and wonderful

There are around 200 different types of anglerfish. Although one giant species grows to over a metre, most anglerfish are tiny – less than 10cm long.

Only female anglerfish have lures. These lures often glow in the dark, thanks to the bio-luminescent bacteria inside them, which presents a tempting (but fake) meal to their unsuspecting prey.

Anglerfish don’t form large schools like many other fish and this represents a problem for them – they need to find a mate. The tiny males have found a solution: if they do happen to find a female, they grasp onto her with their mouths and never let go.

These males tap into the females’ blood stream and never have to eat again. Scientists call this behaviour parasitic. Sometimes more than one male can be attached to a single female. Imagine someone’s father being 100 times smaller than their mother and being permanently attached to her.

Nature is truly weird and wonderful.

Threats

Among the biggest problems for a lot of fish species are disease and overfishing by humans. But it’s highly unlikely that these threats could wipe out anglerfish.

Anglerfish are found between 300 and several thousand metres of water. At this depth, it is constantly dark and the water is cold.

As they live in such deep water and do not form schools, they are not targeted by fishermen, a common threat for many shallow water fish.

And anglerfish are so widely spread across the world’s oceans that any disease is highly unlikely to spread among them.

There is one threat that might affect angler fish – the threat of global warming. Temperatures in the deep ocean are very stable, they simply don’t change much.

Anglerfish live their entire lives at depth with near constant temperatures; hence even small shifts in temperature may affect them. It remains unclear whether increasing temperatures really will threaten angler fish – only time will tell.

Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to us. You can:

* Email your question to curiouskids@theconversation.edu.au * Tell us on Twitter by tagging @ConversationEDU with the hashtag #curiouskids, or * Tell us on Facebook _

Please tell us your name, age and which city you live in. We won’t be able to answer every question but we will do our best.

Andy Davis, Director - Institute for Conservation Biology and Environmental Management, University of Wollongong

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Curious Kids is a series for children. If you have a question you’d like an expert to answer, send it to curiouskids@theconversation.edu.au You might also like the podcast Imagine This, a co-production between ABC KIDS listen and The Conversation, based on Curious Kids.

Why do we sigh? – Sophie, aged 4, East St Kilda, Melbourne.

Dear Sophie,

Thanks for your lovely and excellent question about sighing.

Since you asked a question about sighing, it is probably safe to say that you already know something about breathing. But, for the benefit of everyone else (who might not be an expert like you or me) I am going to talk a little bit about breathing first.

The tiny sacks of life

You have two lungs that you use to breathe. Each lung is a stretchy sack, kind of like a balloon, but not empty like a balloon. Inside your lungs are millions and millions and millions of tiny sacks called alveoli. These tiny sacks called alveoli are very important.

To keep living, we need a gas called oxygen to be moved out of the air and into our blood. And that’s not all! We need another gas called carbon dioxide to be moved in the opposite direction: from out of your blood and into the air.

For these two things to happen, the air and your blood need to be brought very, very close together. This is exactly what happens in the tiny sacks called alveoli that fill your lungs. This is just as well! If you don’t get oxygen in and carbon dioxide out, you will die, which is bad.

When you breathe in, the tiny sacks called alveoli (seriously, your lungs are full of ‘em) get filled with air. At the same time, blood (pumped by your heart) flows around the sides of the tiny sacks.

This brings the air and the blood very close together and so allows the gases to move in the right direction (oxygen in, carbon dioxide out).

Moving these gases is essential for survival, which means that breathing is essential for survival, which means the tiny sacks called alveoli are very, very essential for survival indeed.

Back to sighing

Here’s the thing about the tiny sacks called alveoli: you have so many of them that, actually, you don’t need to use them all at once. When you are sitting quietly, you can get move enough gas by using just some of them.

This is all fine and well, but if you are sitting quietly for a long while, these tiny unused sacks stay unused. And when a sack stays unused for a long time, it tends to collapse in on itself. When the tiny sacks called alveoli that fill your lungs collapse, they can’t be used to move gas in or out of your blood any more, which is bad.

Fortunately, there is a solution: the sigh. A sigh is breath that is deeper than usual, so sighs fill your lungs with more air than a normal breath would.

This means that any tiny sacks (called alveoli) that are not being used get filled up with lovely air when you sigh. This stops them from collapsing and averts the danger! Hooray!

Most of the time, your brain takes care of breathing for you and, fortunately, it takes care of sighing for you too. This means that you don’t need to worry about remembering to sigh.

If you need to worry about remembering anything, Sophie, it’s that you should never stop asking this sort of lovely question. Congratulations: you are now an expert on breathing and sighing.

Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to curiouskids@theconversation.edu.au.

Please tell us your name, age and which city you live in. We won’t be able to answer every question but we will do our best.

David Farmer, Researcher, The University of Melbourne

This article is republished from The Conversation under a Creative Commons license. Read the original article.