Beetles are the most diverse group of animals on Earth, accounting for nearly a quarter of all known animal species. Australia is thought to be home to a whooping 30,000 beetle species, and they are crucial to keeping our ecosystems healthy.

Beetles can be distinguished from other insects by their hard, shell-like wing covers called “elytra”. Unlike other insects, beetles hide their soft, thin wings beneath these protective covers when they are not in use.

Summer is a great time to go beetle-watching in Australia. While beetles can be found all year round, many species are more visible and numerous when the weather heats up.

Beetles come in a brilliant range of colours, patterns and textures – even metallic – which makes them especially fun to spot. Here are five beautiful beetles to look out for this summer.

1. Flower chafers

Although bees get all the glory, beetles are the unsung pollinators of many native plants.

Flower chafers (from the subfamily Cetoniinae) are named after their habit of visiting flowers to feed on nectar and pollen. This makes them important pollinators.

Flower chafer larvae live in rotting wood or leaf litter. There are 146 species in Australia, found in all states and territories..

One of the most common is the fiddler beetle (Eupoecila australasiae), found along Australia’s east coast. It features striking black, green and occasionally yellow markings in a fiddle-shaped pattern.

Female fiddler beetles lay eggs in soil or rotting logs. The larvae burrow through the soil to feed, emerging as adults in the spring.

The fiddler beetle feeds on native flowers such as Angophora, Melaleuca and Leptospermum (tea trees) and may occasionally eat rotting fruit.

Beetle-pollinated flowers are often white or cream, with nectar placed where beetles can readily reach it. The below video shows a native tree on which multiple species are feeding at once.

2. Stag beetles

The larvae of stag beetles (from the family Lucanidae) feed on decaying wood – breaking down tough, fibrous material and returning essential nutrients to the soil.

Adult stag beetles have been described as “beautiful baubles” for their shimmery exoskeletons in shades of gold, green, purple and blue.

Stag beetles are most abundant in Tasmania, New South Wales and Victoria, but are also found in Queensland, South Australia and Western Australia.

3. Christmas beetles

In southern and eastern Australia, the festive season is traditionally marked by the arrival of large numbers of iridescent Christmas beetles (Anoplognathus).

Of the 36 species of Christmas beetle, all but one are found exclusively in Australia, making them a truly iconic part of the country’s natural heritage.

Although Christmas beetles were once reliable heralds of summer, their numbers now appear to be declining. A lack of long-term population monitoring makes it challenging to confirm this trend, however.

4. Jewel beetles

Jewel beetles (from the family Buprestidae) feature brilliantly coloured, metallic bodies – features thought to deter predators.

Australia is lucky to have 1,200 species of these beautiful living jewels, found all across the continent.

Adult jewel beetles feed on nectar and pollen, while their larvae usually bore through the wood of trees or the roots of plants.

5. Diamond weevils

The diamond weevil (Chrysolopus spectabilis) is the crown jewel of Australia’s weevil family. It comes in a startling array of colours, from blue to yellow and green.

Diamond weevils are found commonly along the east coast of Australia, eating plant material such as Acacia leaves.

The species is one of Australia’s first insects named by European scientists. It was first collected in 1770 by naturalist Joseph Banks, who landed at Botany Bay with Captain Cook.

Saving our beetles

Despite their ecological importance and phenomenal diversity, beetles are understudied. Scientists are constantly finding new species, such as the adorable fluffy longhorn beetle (Excastra albopilosa) recently discovered in the Gold Coast hinterland.

Unfortunately beetles – like many other insect species – face increasing threats from habitat loss, climate change and the misuse of insecticide.

A few simple actions can help native beetles to thrive.

Planting nectar-rich natives helps provide a reliable food source for flower-feeding beetles. Choose native plants with large, bowl-shaped or flattened flowers which makes the nectar easy for insects to reach. Good examples include the dwarf apple (Angophora hispida), white kunzea (Kunzea ambigua) and rice flower (Ozothamnus diosmifolius).

As a bonus, flowers also attract pest-eating beetles such as ladybirds.

Many beetles rely on decaying leaves and wood for food and shelter. So try to avoid disturbing or removing rotting wood and leaf litter from natural habitats.

Avoid using insecticides in home gardens. Many insecticides commonly used to target pest beetles, such as the invasive Argentinian scarab, indiscriminately kill beneficial ground-dwelling beetle larvae.

And help scientists better understand beetle populations and their conservation needs by uploading beetle sightings to online platforms such as iNaturalist and Canberra Nature Mapr.

Public sightings can have a big impact. Participants in the annual Christmas Beetle Count have rediscovered seven species not seen for decades.

By protecting our valuable – and stunning – Australian beetles, we can ensure they survive for future generations to enjoy.

Tanya Latty, Associate Professor, School of Life and Environmental Sciences, University of Sydney and James Bickerstaff, Postdoctoral Research Fellow, Australia National Insect Collection, CSIRO

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

Summer is a wonderful time for families to go the beach and for small children to get to know the water and the sand.

But aside from being a place to relax, my new research shows how the beach provides many ways to teach young children about science.

My ‘beach kinder’ research

I research science, technology, engineering and mathematics (STEM) learning in bush kinders. These are programs where preschool children regularly go into the natural environment with their daycare centre or kinder/preschool, to gain an appreciation for nature.

Educators do not take any toys, balls or games, so children are reliant only on what is available in nature for play.

Bush kinders often happen in parks, forests and gardens but educators and researchers are increasingly looking at the benefits of education around beaches. These “blue spaces” provide children with wide open spaces to learn through play.

But so far there has been little research on educational benefits of beach learning in early childhood settings.

Last year, I observed a “beach kinder”: where childhood educators and four- and five-year-old children went to the beach along Victoria’s Surf Coast. They were spending between three and five hours per week at the beach for a term as part of their regular kinder/preschool program.

What I noticed was how many opportunities the beach provides to teach little kids about science. Here are a three examples families can try on their next visit to the beach.

1. Rockpool life

When the tide is low, the ocean can expose a wide range of plant and animal life. Small fish, crabs, starfish, sea plants and maybe even an octopus can be found in rockpools. You can ask your child:

How many different animals can you see?

You can also search for barnacles that look like small volcanoes or periwinkles – the little snails that live in the splash zone. You can talk about how animals can sometimes be very small or hiding – just because we can’t see them does not mean they are not there.

You can talk to children about how these small animals survive as the tide rises and falls. For example, crabs bury themselves in the sand away from the water or other types of shellfish can shut their shells tightly to keep the water out. If possible, gently lift one for a look and then replace it just as gently.

You can explain life cycles and simple biology as you walk among the rockpools. For example, sea turtles lay their eggs on sandy beaches, then the baby turtles make their way to the sea where they mature into adults.

2. Sticky sand

Sand is an amazing thing to play with and it changes, depending on where you are on the beach.

Far away from the waters’ edge, have your child take a handful of dry sand and watch what happens as it slips through small hands. Walk closer to the water and do the same thing. Ask your child:

Have you ever wondered why dry and wet sand are so different?

You can explain how the water in the sand actually acts like glue, making the sand grains stick together. This lets us talk to young children about chemistry and how different materials interact with each other.

Try making sandcastles with wet sand and dry sand and see the difference.

Is one version harder to work with than the other other? What happens if you mix wet and dry sand together?

3. Watching the waves

The waves can teach us about floating, sinking and the force of water.

Children can have a lot of fun using pieces of seaweed or small sticks as boats, letting them bob up and down on small waves. They can even have “seaweed races” learning about how waves can move materials around.

Sea waves and ocean currents are really important as some marine animals such as dolphins and turtles use waves to move around. In fact, some animals migrate thousands of kilometres to and from breeding grounds.

You can then replace the seaweed pieces with shells and ask your child to observe what happens:

Why does the seaweed stay on top of the water, but the shell goes underneath?

Talk about how the shell is heavier than the water and so will sink. This helps them understand the physics of floating and sinking as well as the patterns associated with wave motion.

This summer when you’re at the beach, think about all the science happening around you. This could include the animals and habitats you encounter, as well as all the many, changes things happening with the sand and surf.

Chris Speldewinde, Research fellow, Research for Educational Impact Institute, Deakin University

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

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to CuriousKidsUS@theconversation.com.

How is the International Space Station able to orbit without burning up? – Mateo, age 8, New York, New York

Flying through Earth’s orbit are thousands of satellites and two operational space stations, including the International Space Station, which weighs as much as 77 elephants. The International Space Station, or ISS, hosts scientists and researchers from around the world as they contribute to discoveries in medicine, microbiology, Earth and space science, and more.

One of my first jobs in aerospace engineering was working on the ISS, and the ISS remains one of my favorite aerospace systems. I now work at Georgia Tech, where I teach aerospace engineering.

The ISS travels very quickly around the Earth at 5 miles per second (8 kilometers per second), which means it could fly from Atlanta to London in 14 minutes. But at the same time, small chunks of rock called meteoroids shoot through space and burn up when they hit Earth’s atmosphere. How is it that some objects – such as the International Space Station – orbit the Earth unscathed, while others, such as asteroids, burn up?

To answer why the ISS can stay in orbit for decades unscathed, you first need to understand why some things, such as meteoroids, do burn up when they enter our planet’s atmosphere.

Why do meteoroids burn up in the atmosphere?

Meteoroids are small chunks of rock and metal that orbit the Sun. These space rocks can travel between 7 and 25 miles per second (12 to 40 km per second). That’s fast enough to cross the entire United States in about 5 minutes.

Sometimes, the orbit of a meteoroid overlaps with Earth, and the meteoroid enters Earth’s atmosphere – where it burns up and disintegrates.

Even though you can’t see them, the atmosphere is full of a combination of particles, primarily nitrogen and oxygen, which make up the air you breathe. The farther you are from the surface of the Earth, the lower the density of particles in the atmosphere.

The atmosphere has several layers. When something from space enters the Earth’s atmosphere, it must pass through each of these layers before it reaches the ground.

Meteoroids burn up in a part of Earth’s atmosphere called the mesosphere, which is 30 to 50 miles (48 to 80 kilometers) above the ground. Even though the air is thin up there, meteoroids still bump into air particles as they fly through.

When meteoroids zoom through the atmosphere at these very high speeds, they are destroyed by a process that causes them to heat up and break apart. The meteoroid pushes the air particles together, kind of like how a bulldozer pushes dirt. This process creates a lot of pressure and heat. The air particles hit the meteoroid at hypersonic speeds – much faster than the speed of sound – causing atoms to break away and form cracks in the meteroid.

The high pressure and hot air get into the cracks, making the meteoroid break apart and burn up as it falls through the sky. This process is called meteoroid ablation and is what you are actually seeing when you witness a “shooting star.”

Why doesn’t the ISS burn up?

So why doesn’t this happen to the International Space Station?

The ISS does not fly in the mesosphere. Instead, the ISS flies in a higher and much less dense layer of the atmosphere called the thermosphere, which extends from 50 miles (80 km) to 440 miles (708 km) above Earth.

The Kármán line, which is considered the boundary of space, is in the thermosphere, 62 miles (100 kilometers) above the surface of the Earth. The space station flies even higher, at about 250 miles (402 km) above the surface.

The thermosphere has too few particles to transmit heat. At the height of the space station, the atmosphere is so thin that to collect enough particles to equal the mass of just one apple, you would need a box the size of Lake Superior!

As a result, the ISS doesn’t experience the same kind of interactions with atmospheric particles, nor the high pressure and heat that meteoroids traveling closer to Earth do, so it doesn’t burn up.

A high-flying research hub

Although the ISS doesn’t burn up, it does experience large temperature swings. As it orbits Earth, it is alternately exposed to direct sunlight and darkness. Temperatures can reach 250 degrees Fahrenheit (121 degrees Celsius) when it’s exposed to the Sun, and then they can drop to as low as -250 degrees F (-156 degrees Celsius) when it’s in the dark – a swing of 500 degrees F (277 degrees C) as it moves through orbit.

The engineers who designed the station carefully selected materials that can handle these temperature swings. The inside of the space station is kept at comfortable temperatures for the astronauts, the same way people on Earth heat and cool our homes to stay comfortable indoors.

Research on the ISS has led to advancements such as improved water filtration technologies, a better understanding of Earth’s water and energy cycles, techniques to grow food in space, insights into black holes, a better understanding of how the human body changes during long-duration space travel, and new studies on a variety of diseases and treatments.

NASA plans to keep the ISS active until 2030, when all of the astronauts will return to Earth and the ISS will be deorbited, or brought down from orbit by a specially designed spacecraft.

As it comes down through Earth’s atmosphere in the deorbiting process, it will enter the mesosphere, where many parts of it will heat up and disintegrate.

Some spacecraft, such as the crew capsules that bring astronauts to and from the ISS, can survive reentry into the atmosphere using their heat shield. That’s a special layer made up of materials that are able to withstand very high temperatures. The ISS wasn’t designed for that, so it doesn’t have a heat shield.

If you’d like to see the space station as it passes over your area, you can check out NASA’s website to find out when it might be visible near you.

Hello, curious kids! Do you have a question you’d like an expert to answer? Ask an adult to send your question to CuriousKidsUS@theconversation.com. Please tell us your name, age and the city where you live.

And since curiosity has no age limit – adults, let us know what you’re wondering, too. We won’t be able to answer every question, but we will do our best.

Kelly Griendling, Lecturer of Aerospace Engineering, Georgia Institute of Technology

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

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to curiouskidsus@theconversation.com.

What is the universe expanding into if it’s already infinite? – Mael, age 10, Missoula, Montana

When you bake a loaf of bread or a batch of muffins, you put the dough into a pan. As the dough bakes in the oven, it expands into the baking pan. Any chocolate chips or blueberries in the muffin batter become farther away from each other as the muffin batter expands.

The expansion of the universe is, in some ways, similar. But this analogy gets one thing wrong – while the dough expands into the baking pan, the universe doesn’t have anything to expand into. It just expands into itself.

It can feel like a brain teaser, but the universe is considered everything within the universe. In the expanding universe, there is no pan. Just dough. Even if there were a pan, it would be part of the universe and therefore it would expand with the pan.

Even for me, a teaching professor in physics and astronomy who has studied the universe for years, these ideas are hard to grasp. You don’t experience anything like this in your daily life. It’s like asking what direction is farther north of the North Pole.

Another way to think about the universe’s expansion is by thinking about how other galaxies are moving away from our galaxy, the Milky Way. Scientists know the universe is expanding because they can track other galaxies as they move away from ours. They define expansion using the rate that other galaxies move away from us. This definition allows them to imagine expansion without needing something to expand into.

The expanding universe

The universe started with the Big Bang 13.8 billion years ago. The Big Bang describes the origin of the universe as an extremely dense, hot singularity. This tiny point suddenly went through a rapid expansion called inflation, where every place in the universe expanded outward. But the name Big Bang is misleading. It wasn’t a giant explosion, as the name suggests, but a time where the universe expanded rapidly.

The universe then quickly condensed and cooled down, and it started making matter and light. Eventually, it evolved to what we know today as our universe.

The idea that our universe was not static and could be expanding or contracting was first published by the physicist Alexander Friedman in 1922. He confirmed mathematically that the universe is expanding.

While Friedman proved that the universe was expanding, at least in some spots, it was Edwin Hubble who looked deeper into the expansion rate. Many other scientists confirmed that other galaxies are moving away from the Milky Way, but in 1929, Hubble published his famous paper that confirmed the entire universe was expanding, and that the rate it’s expanding at is increasing.

This discovery continues to puzzle astrophysicists. What phenomenon allows the universe to overcome the force of gravity keeping it together while also expanding by pulling objects in the universe apart? And on top of all that, its expansion rate is speeding up over time.

Many scientists use a visual called the expansion funnel to describe how the universe’s expansion has sped up since the Big Bang. Imagine a deep funnel with a wide brim. The left side of the funnel – the narrow end – represents the beginning of the universe. As you move toward the right, you are moving forward in time. The cone widening represents the universe’s expansion.

Scientists haven’t been able to directly measure where the energy causing this accelerating expansion comes from. They haven’t been able to detect it or measure it. Because they can’t see or directly measure this type of energy, they call it dark energy.

According to researchers’ models, dark energy must be the most common form of energy in the universe, making up about 68% of the total energy in the universe. The energy from everyday matter, which makes up the Earth, the Sun and everything we can see, accounts for only about 5% of all energy.

Outside the expansion funnel

So, what is outside the expansion funnel?

Scientists don’t have evidence of anything beyond our known universe. However, some predict that there could be multiple universes. A model that includes multiple universes could fix some of the problems scientists encounter with the current models of our universe.

One major problem with our current physics is that researchers can’t integrate quantum mechanics, which describes how physics works on a very small scale, and gravity, which governs large-scale physics.

The rules for how matter behaves at the small scale depend on probability and quantized, or fixed, amounts of energy. At this scale, objects can come into and pop out of existence. Matter can behave as a wave. The quantum world is very different from how we see the world.

At large scales, which physicists call classical mechanics, objects behave how we expect them to behave on a day-to-day basis. Objects are not quantized and can have continuous amounts of energy. Objects do not pop in and out of existence.

The quantum world behaves kind of like a light switch, where energy has only an on-off option. The world we see and interact with behaves like a dimmer switch, allowing for all levels of energy.

But researchers run into problems when they try to study gravity at the quantum level. At the small scale, physicists would have to assume gravity is quantized. But the research many of them have conducted doesn’t support that idea.

One way to make these theories work together is the multiverse theory. There are many theories that look beyond our current universe to explain how gravity and the quantum world work together. Some of the leading theories include string theory, brane cosmology, loop quantum theory and many others.

Regardless, the universe will continue to expand, with the distance between the Milky Way and most other galaxies getting longer over time.

Hello, curious kids! Do you have a question you’d like an expert to answer? Ask an adult to send your question to CuriousKidsUS@theconversation.com. Please tell us your name, age and the city where you live.

And since curiosity has no age limit – adults, let us know what you’re wondering, too. We won’t be able to answer every question, but we will do our best.

Nicole Granucci, Instructor of Physics, Quinnipiac University

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

Why do trees have bark? Julien, age 6, Melbourne.

This is a great question, Julien.

We are so familiar with bark on trees, that most of us just take it for granted. But bark is one of the most complex parts of a tree and has many different jobs to do. Without bark we would not have trees as we know them.

Here’s what bark does – and why it is so special.

Bark helps trees move stuff around the plant

Bark on many trees is made of two different things.

The first thing is called phloem and it is pretty complicated stuff. Its main job is to transport chemicals like sugars and hormones up, down and around the tree. In fact, phloem can move just about anything the plant needs around the tree. That’s a very good reason why trees have bark.

The second thing is called cork and in many trees, phloem and cork are mixed together. Cork helps protect the tree from harmful insects and fungi. It also helps keep certain parts of the tree from getting too hot or too cold. Like us, trees function best at just the right temperatures. So this protection is an important reason why trees have bark.

Some trees have thin smooth bark that falls off every year in great sheets and strips.

Other trees have thicker, furry or crinkly bark that is shed in bits and pieces over months or many years.

As the tree gets bigger, the bark has to be regularly replaced. It is a bit like the skin on a snake.

Bark can help a tree survive and thrive

Bark makes an excellent home for other living things, such as insects, spiders and fungi.

Some of these even help the tree survive and thrive. Bark is a good and safe place for these tree helpers to call home.

The bark can also stop the trunk of the tree from losing too much water and drying out. It can also stop too much water getting in when it rains or floods.

These are all are good reasons for trees to have bark.

Many Australian native trees have thick bark that protects the tree trunks during bushfires. The thick, hard bark on some trees can also help the tree survive the fire and sprout quickly after a bushfire.

While bark is not as strong as the wood on the inside of a tree, it still adds some strength to tree trunks.

Being more flexible than wood, bark can also move and bend in the wind with minimal damage, except in the most severe storms.

Some trees, such as yellow gum (also known as Eucalyptus leucoxylon) have a sort of “skirt” of thicker bark around their base. This “skirt” protects the lower trunks from damage, especially in fires.

Bark can be useful to people too

Some trees, like the cork oak (also known as Quercus suber) have a cork layer that can be more than 15-20cm thick. This thick layer protects these oak trees from fires too, but the cork is also harvested. People can use it to make wine bottle corks or cork building materials for homes, without harming the tree.

Some people also like to make art out of bark. Maybe if you see some bark on the ground you can take it home and look at it with a magnifying glass. You might see some interesting patterns! When you’re finished, maybe you could make a decoration or artwork out of the bark.

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

Gregory Moore, Senior Research Associate, School of Ecosystem and Forest Sciences, The University of Melbourne

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

How does toothpaste work? What did people use before toothpaste was invented? – Amelia, age 7, Meanjin (Brisbane)

Thanks for your great questions, Amelia.

I’m a dentist, so I know a bit about how toothpaste works and what we used before it was invented.

How does toothpaste work?

Toothpaste makes your mouth smell fresh and feel clean. If you brush your teeth two times a day, toothpaste also helps protect your teeth from forming holes or cavities. Let’s look at these benefits one at a time.

That fresh feeling

Some toothpaste ingredients mix with your spit (or saliva) to make a soapy sudsy foam. The sudsy foam turns into slimy slop that you spit out.

Many toothpastes also have a slight sandy feeling to scrub stains off your teeth. This also helps remove the sticky, soft, white globs that grow on your teeth called plaque (pronounced plark).

Plaque is made from sticky bits of food and bacteria (tiny bugs). The bacteria in your plaque live, grow and multiply in your mouth. Some bacteria – such as Streptococcus mutans (pronounced strep-toe-cock-us mew-tans) – love to digest the sugary food you eat. Other bacteria in your plaque burp rotten-egg gases that make your breath smell.

No wonder we want to get rid of plaque with gassy bacteria.

Prevents cavities

Even worse, plaque bacteria poo out diarrhoea (pronounced die-ree-a). That diarrhoea is “acidic”, meaning it can dissolve your teeth to form holes. So we brush our teeth twice a day to get rid of as much bacteria and their diarrhoea as we can.

There are lots of special ingredients in toothpastes to prevent holes from forming that include:

• xylitol (pronounced zy-lee-toll). When bacteria in your plaque eat this, they get constipated and poo less acid

• fluoride (pronounced floor-ride). Your teeth have tiny gaps on the surface that are so small you can only see them with a microscope. Fluoride fills these gaps to make your teeth strong. This is how fluoride protects against nasty bacteria poo from dissolving your teeth.

What did people use in the olden days?

People who lived a long time ago didn’t know much about Streptococcus mutans and bacteria poo. They thought getting holes in teeth was part of growing up. They were wrong. But they tried to make their teeth look whiter by using tooth powders.

People in ancient Egypt, China and India used their fingers to rub tooth powders on their teeth.

The first tooth powders were made of crushed animal bones, ox hooves, and egg, snail and oyster shells. Later, people added crushed charcoal (the black stuff you get when you burn bones or wood), powdered tree bark and flavouring herbs.

The ancient Romans cleaned their teeth with toothpaste made with pee.

Thank goodness things have changed.

Thank your lucky stars

The next time you brush your teeth, think of all those people in the olden days. They made tooth powders with bones and shells, and toothpaste with pee.

Luckily, we now have toothpastes that leave a better taste in your mouth and stop holes forming in your teeth.

But when you brush your teeth, remember to spit out the toothpaste. Don’t rinse it away with water. We want to keep a bit in your mouth to protect your teeth from that nasty bacteria poo.

Hello, Curious Kids! Do you have a question you’d like an expert to answer? Ask an adult to send your question to curiouskids@theconversation.edu.au

Arosha Weerakoon, Senior Lecturer and General Dentist, School of Dentistry, The University of Queensland

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