A few years ago, 10-year-old Guy was driving along the Australian coast when he saw whales, spouting water up into the air. He was amazed. “Then my brother farted, and then I wondered if whales fart,” says Guy.

Guy joined our host Eloise to put his question to Vanessa Pirotta, a wildlife scientist at Macquarie University in Australia on this week’s episode of The Conversation’s Curious Kids podcast.

In each episode of The Conversation’s Curious Kids, a curious kid joins host Eloise to ask a top researcher their burning question. This episode is a follow-on from the episode “Do whales sneeze?” in our first season.

To listen to season two, follow us wherever you get your podcasts, or listen on the Yoto Player via the Discover section on the Yoto interactive audio platform for kids.

You can also listen back to season one and read lots of answers to questions sent in by children around the world in our Curious Kids series.

Got a question? Pop it in an email, or record it and send us the audio to curiouskids@theconversation.com.

This season of The Conversation’s Curious Kids is supported by the University of Southampton in the UK, a world-leading research-intensive university with a global network of international students and campuses in Malaysia and Delhi.

Disclosure statement

Vanessa Pirotta does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

Credits

This episode of The Conversation’s Curious Kids was hosted and mixed by Eloise Stevens. The producer was Katie Flood and the executive producer was Gemma Ware. Audio clips from Finding Nemo, and seal pup sounds from schaarsen and whale noise from kaekhor via Freesound.

Eloise Stevens, Host, The Conversation's Curious Kids podcast, The Conversation and Gemma Ware, Head of Audio, The Conversation UK, The Conversation

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

Have you noticed that something you find absolutely delicious might taste disgusting to someone else? Well nine-year-old Leo from Wigan in the UK wanted to know why that is – and why our taste for certain foods changes?

Leo joined our host Eloise to put his question to taste researcher Linda Bartoshuk on The Conversation’s Curious Kids podcast.

In each episode of The Conversation’s Curious Kids, a child joins host Eloise to ask a top researcher their burning question. If you’d like to join in with the experiment in this episode, make sure you have packet of jelly beans or jelly babies to hand!

To listen to season two, follow us wherever you get your podcasts, or listen on the Yoto Player via the Discover section on the Yoto interactive audio platform for kids.

You can also listen back to season one and read lots of answers to questions sent in by children around the world in our Curious Kids series.

Got a question? Pop it in an email, or record it and send us the audio to curiouskids@theconversation.com.

This season of The Conversation’s Curious Kids is supported by the University of Southampton in the UK, a world-leading research-intensive university with a global network of international students and campuses in Malaysia and Delhi.

Disclosure statement

Linda Bartoshuk has received funding from the National Institutes of Health.

Credits

This episode of The Conversation’s Curious Kids was hosted and mixed by Eloise Stevens. The producer was Katie Flood and the executive producer was Gemma Ware.

Eloise Stevens, Host, The Conversation's Curious Kids podcast, The Conversation and Gemma Ware, Head of Audio, The Conversation UK, The Conversation

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

There are currently 118 chemical elements on the periodic table. The last one added was oganesson, which was first created by scientists in 2002.

Seven-year-old Robin, from Edinburgh in Scotland, wants to know whether scientists will be able to make any more new elements, and how they do it. He joined our host Eloise to ask biochemist Mark Lorch on The Conversation’s Curious Kids podcast.

In each episode of The Conversation’s Curious Kids, a child joins host Eloise to ask a top researcher their burning question. If you’d like to join in with the experiment in this episode, have a few pieces of lego to hand as you listen.

To listen to season two, follow us wherever you get your podcasts, or listen on the Yoto Player via the Discover section on the Yoto interactive audio platform for kids.

You can also listen back to season one and read lots of answers to questions sent in by children around the world in our Curious Kids series.

Got a question? Pop it in an email, or record it and send us the audio to curiouskids@theconversation.com.

This season of The Conversation’s Curious Kids is supported by the University of Southampton in the UK, a world-leading research-intensive university with a global network of international students and campuses in Malaysia and Delhi.

Disclosure statement

Mark Lorch does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

Credits

This episode of The Conversation’s Curious Kids was hosted and mixed by Eloise Stevens. The producer was Katie Flood and the executive producer was Gemma Ware. Credits in this episode to The Tom Lehrer Wisdom Channel and the BBC.

Eloise Stevens, Host, The Conversation's Curious Kids podcast, The Conversation and Gemma Ware, Head of Audio, The Conversation UK, The Conversation

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.

Why are our fingers different lengths? – Betty, age 8, California

It was one of those rushed mornings when I was already running late for work. In my hurry to grab my keys and head out the door, I knocked a few things off the counter, scattering loose coins onto the floor.

As I picked up the coins, I noticed I was using different movements to gather everything, and those movements seemed to depend on the different lengths of my fingers. My thumb and index finger pinched together to grab a dime, while my middle finger reached farther to pick up coins that had rolled under the edge of a cabinet. My ring finger and pinky curled inward to hold the coins I had already collected while I reached for more.

These motions really brought home how different fingers have their own job – and how each finger’s varying length plays a big part in what it can do.

Pondering such things is part of my job description: As a biological anthropologist who studies the biomechanics of how people move, I often think about how movement, forces and structure work together to shape the human body.

Team of 5

My morning mishap showed that each of my five fingers seemed to have its own role, and the differences in finger length helped them do different jobs.

The middle finger is usually the longest. It acts as the hand’s central axis, helping to balance and guide movements. Its length also allows it to work with the other fingers to grip objects securely.

The ring finger is typically slightly shorter than the middle finger, but the two work closely together, generating grip strength and stabilizing the hand. Whether lifting a heavy backpack, carrying grocery bags or holding a baseball bat, the middle and ring fingers help keep your grip steady and balanced.

The index finger is shorter, more flexible and can move on its own more easily than the two main gripping fingers – which makes it great for careful, controlled movements. It is the finger you use for tasks that require precision and accuracy, such as pointing, typing, pressing small buttons or writing with a pencil.

The pinky finger is usually the smallest of the five, but it doesn’t need length to do its job of steadying the outer edge of the hand. It helps keep your hand stable when you hold things – especially objects that are bigger than your hand, such as a large water bottle, basketball or a heavy bag of groceries.

The thumb is unique. It’s generally about three-quarters the length of the index finger. Rather than relying on length, the thumb’s special joint lets it rotate and move across the palm, where it can touch the other fingers. Because it can move this way, it is called an opposable thumb. This makes the thumb one of the most versatile parts of the hand, enabling you to pinch and pick up small objects.

Without the thumb, many everyday tasks, such as holding utensils, opening containers and, yes, picking up coins, would be much harder.

An evolving tool

Evolution shaped the human hand into a highly capable tool. Early humans relied on their hands for survival tasks, such as climbing, building, and making and using tools.

Those with hands better suited for gripping and precision were more likely to thrive, gradually shaping the modern human hand.

For example, humans share our long middle finger with other apes, including chimpanzees and gorillas, suggesting that it has been important throughout our evolutionary history. This long history of adaptation explains why our hands are both strong and highly precise, capable of handling everything from heavy lifting to delicate tasks.

A biological blueprint

Evolution is only part of the story. Before birth, genes guide how the hands grow, acting like a biological blueprint during development.

These genes influence how quickly bones lengthen, how long each finger becomes, and how the joints and tendons are shaped. Small differences in how these genes work before birth can change how long each finger grows compared with the others.

Hormones also play an important role. Sex hormones, such as testosterone and estrogen, and other signals can influence how the bones of the fingers grow, shaping subtle differences in proportions before birth and into childhood and adolescence.

Hand development is shaped by both biology and environment. This is why families often share similar hand features, even though each person’s hands and fingers are slightly different.

As we use our hands every day, we become better at tasks such as writing, throwing or playing an instrument. Over time, our hands grow stronger and more coordinated through practice.

So why are our fingers different lengths? There is no single answer. Evolution shaped the hand, with fingers that specialize in different tasks, while genes and hormones guide how those fingers develop.

Together, these forces produced a hand in which each finger has a different size, shape and role, helping us perform everything from powerful grips to delicate movements.

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.

Steven Lautzenheiser, Assistant Professor of Biological Anthropology, University of Tennessee

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.

Can anyone make a black hole in a laboratory? – Sohini B., age 13, Kolkata, West Bengal, India

A black hole is an object so massive and dense that even light cannot escape its gravity. They occur in space when extremely dense objects, such as the centers of stars, collapse.

All the black holes observed in space are the products of natural processes and are very far away.

As an astronomer, I study how black holes interact with their surroundings. Creating a black hole in a lab would be an amazing opportunity to learn more about how the universe works. But is it even possible?

What does it take to make a black hole?

Any amount of mass can be turned into a black hole if you cram it into a small enough space, but you would need an extremely high density, or mass per volume, to create one on Earth. Water has a density of 1 gram per cubic centimeter. That’s about 8 pounds per gallon. The densest common element, lead, is 11 times denser. That’s still nowhere near dense enough to make a black hole. To do so, gravity needs to overcome the very strong forces that create bonds inside atoms and give matter its structure.

Objects in space can be much, much denser than things on Earth. A massive dying star can collapse into a very dense object called a neutron star when the gravity of the star’s core overcomes the pushing force between atoms. When this phenomenon happens, all the matter in the neutron star fuses into one big atom, with a density of about a million billion g/cc. A single teaspoon of a neutron star is a thousand times heavier than the Great Pyramid of Giza in Egypt!

If a neutron star gets more massive and more dense, the forces that hold atoms together can finally surrender to gravity, and all the mass collapses inward. At some point, the speed needed to escape its gravity becomes greater than the speed of light, which means nothing can escape, and all the particles around the star get sucked inside. Instead of one big atom, it’s now a black hole.

A black hole with the mass of the Earth would have a radius of about half an inch, which is about the size of your thumb. Its density would be in the range of a billion billion billion g/cc.

The smallest artificial objects are tiny computer chips and biomedical devices 100 million times smaller than your thumb. If you could stuff a metric ton – 2,000 pounds, about the weight of a small car – of material into the smallest computer chip, that would get you a black hole.

Is this possible in a lab today?

In short, no. There is no way to artificially produce the huge densities described above. The densest everyday material is many millions of times less dense than what is needed to produce a tiny black hole.

When huge, underground particle accelerators are activated, people sometimes worry that they will create tiny black holes by colliding bits of matter at very rapid speeds. Don’t worry, black holes aren’t produced this way.

While some particle accelerators can create conditions as hot and dense as the big bang, they don’t produce black holes.

Would it be possible in the future?

It’s hard to know how technology will develop in the future, but the laws of physics are going to stay the same. Normal matter can’t be stuffed into a space tiny and dense enough without overcoming a huge outward pressure.

There is a loophole that some scientists think could get around this problem. Only some types of particles push against each other with outward pressure.

Some particles don’t resist being in the same space. You can stack as many of them as you like in a given volume. A particle of light, called a photon, is one such particle, so it’s conceivable that many, many photons could be focused at a single point and create the density needed to create a black hole.

This type of black hole is called a “kugelblitz.” To create a kugelblitz, you’d need to convert a huge amount of mass directly into energy and then focus all that energy down onto a minute area of space. Some scientists think that powerful lasers could achieve this effect. Others say there’s no way to focus enough light. For now, this idea is still science fiction.

What would happen if scientists successfully created one?

Many people think that once something falls down a black hole, it’s gone forever, but most scientists think this is not the case. Stephen Hawking’s most famous theory was the idea that black holes gradually lose their mass. A small black hole would “evaporate” in this way very quickly.

Because any black hole created in a lab would be tiny, it would immediately evaporate in a flash of high-energy light. An artificial one would probably exist only for a fraction of a second before harmlessly disappearing.

So, the creation of an artificial black hole is impossible with our current technology, and it might be completely impossible due to the laws of physics. Still, thinking about black holes and how they would affect objects around them helps scientists understand the way the universe works.

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.

Stephen DiKerby, Postdoctoral Researcher in Physics and Astronomy, Michigan State University

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