QwertyKids

Curious Kids: how do you know that we aren’t in virtual reality right now?

The Conversation — Thu, 24 Oct 2019 05:00:07 +0000

Is this the real life? Or is this just fantasy? Nan Palmero/Flickr, CC BY-SA

Author: Tim Dean, Honorary Associate in Philosophy, University of Sydney

How do you know that we aren’t in virtual reality right now? It could be so realistic that it feels like normal life. – Erin, 13, Strathfield.

Have you ever had a dream where you thought everything around you was real, and then you wake up and realise it was all a dream? If so, how do you know you’re not dreaming right now?

The Chinese philosopher Zhaungzi had this very thought more than 2,000 years ago. He woke up from dreaming that he was a butterfly, but then couldn’t be sure that he wasn’t a butterfly dreaming he was a man.

It is easy to believe the world around us is real. But it’s possible that it’s a dream or a very complex computer simulation. Maybe we’re all plugged into a very powerful computer that is providing us with a virtual reality experience that makes us think we’re somewhere else.

If the simulation is really good and looks like the real world, we might not know we’re in a simulation.

So the short answer is we cannot ever be absolutely 100% certain we’re not in a computer simulation, or that we’re dreaming instead of being awake.

But while this might seem like a strange or disturbing thought, it actually makes no difference to the way we live.

If you have friends and family, and things you enjoy doing, it doesn’t really matter if they’re a part of a dream or a simulation, because you will still behave in the same way.

You’ll still be nice to your friends, you’ll still love your family (even if they might annoy you), you’ll still enjoy the taste of your favourite foods, and you’ll still hate getting up early in the morning.

Children can have their own questions answered by experts – just send them in to Curious Kids, along with the child’s first name, age and town or city. You can:

email curiouskids@theconversation.com
tweet us @ConversationUK with #curiouskids
DM us on Instagram @theconversationdotcom

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

Curious Kids: how do mobile phones and tablets work?

The Conversation — Thu, 17 Oct 2019 05:00:09 +0000

Like magic. Shutterstock.

Author: Bernie Tiddeman, Reader in Computer Science, Aberystwyth University

How do mobile phones and tablets work? Tom, aged six, Quorn, UK

Great question, Tom! There’s a lot of amazing technology packed into mobile phones and tablets. Nowadays, most have a touch screen, speakers, a microphone, WiFi, Bluetooth, a camera, a telephone and more.

Underneath all these fun features, though, mobile phones and tablets are basically mini computers. And computers work by carrying out instructions we humans have given them.

To a computer, everything is a number. A picture? Lots of numbers: three for every tiny dot in the image. A sound? A long list of numbers, including one for how “loud” the sound is at each point in time (that’s thousands every second). A word? Each letter has its own unique number, too.

Machine brains

Computers have a machine “brain” called the Central Processing Unit (CPU), which has two main jobs: getting instructions from the computer’s memory, and carrying them out. The instructions are stored as numbers, too, of course.

The programs or “apps” you find on a mobile phone or tablet are basically lists of instructions. With a bit of practice, you can even write your own: it’s called “programming” or “coding”.

But writing down lots of lists of numbers to give your instructions to the computer would be really difficult, and takes a very long time. Luckily, people have invented special coding languages, that are much easier for us to read and understand.

There are lots of different programming languages these days, with names like C, C++, Python and Java. Different languages are better for different jobs – but mostly it’s just down to what the programmer likes to use.

There are even programming languages made of different shapes, like a jigsaw, which can be great for learning – like Scratch, which you can use to make games.

Learning to code can be lots of fun. Shutterstock.

Once you’ve used one of those languages to make a list of instructions, you run it through a special programme – called a compiler – that turns them into programs or apps that computers can run.

Powering up

The most important program on any mobile phone or tablet is the operating system. The operating system runs all the different programs and helps them use the phone’s different features, like speakers, touchscreen and microphones.

The operating system also lets you do lots of things at once, so you can still get a phone call even while you’re playing a game.

And, of course, mobile phones wouldn’t be very “mobile” without a battery. Batteries have been around for at least 200 years, but they have got a lot better recently, so they can power complicated things like mobile phones, tablets – and even electric cars.

Batteries work by converting chemicals to electricity. With an adult’s help, you can make a simple battery using fruit and some coins, which is fun – but wouldn’t be strong enough to run a mobile phone.

Children can have their own questions answered by experts – just send them in to Curious Kids, along with the child’s first name, age and town or city. You can:

email curiouskids@theconversation.com
tweet us @ConversationUK with #curiouskids
DM us on Instagram @theconversationdotcom

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

Curious Kids: why do we have a QWERTY keyboard instead of putting the letters in alphabetical order?

The Conversation — Thu, 10 Oct 2019 05:00:26 +0000

Many other key arrangements have been tried. Some are claimed to be easier to learn or faster to use than QWERTY. But none has proved good enough to beat QWERTY. Flickr/Jeff Eaton, CC BY-SA

Author: Geoff Cumming, La Trobe University

Why are the letters on the keyboard not in alphabetical order?? – Baker, age 9, Arrowtown, New Zealand.

Great question! That question really puzzled me when I was a kid. And so as a grown-up, I decided to research it and write a paper about it.

Let’s turn the clock back. About 150 years ago, all letters and business papers were written by hand. Most likely they were written using a pen that had to be dipped in ink every word or two. Writing was slow and messy.

Then some clever inventors built a machine for typing. The first typewriters were big heavy metal machines that worked a bit like a piano.

Have you ever seen the inside of a real piano? You press a key and some clever levers make a felt hammer hit just the right piano string to make a note.

Inside a piano.

Early typewriters were similar. They had all these levers with a metal alphabet letter at the end of it. You had to press a letter key quite hard to make the metal lever fly across and hit the paper. Hit the A key and the A lever would hit the paper and type A. The paper then shifted a bit to the left, so the next key would hit in just the right place next to the A. Press more keys and you could type a word, or even a whole book.

The first machine had the letter keys in alphabetical order. The trouble was that if you hit two keys quickly the levers would jam. Jams were most likely when the two keys were close together on the keyboard. Rearranging the letters could reduce jams.

Rearranging the letters reduced the risk that two levers would jam.

Christopher Sholes was an American inventor who was most successful in reducing jams. He tried various arrangements, always trying to reduce the need to type two keys that were close together. The best arrangement he could find was similar to the QWERTY keyboard we all use today. (Look at the top row of a keyboard to see why it’s called QWERTY.)

He sold his invention to the Remington Company in the United States. In the 1870s, that company built and sold the first commercially successful typewriters. They used the QWERTY keyboard.

For 100 years or so after the Remington typewriter arrived, vast numbers of people all over the world trained to become touch typists (meaning they could type even without looking much at the keyboard). They were employed to type letters and all other kinds of things for business and government. Because so many people became so skilled at using QWERTY, it became very difficult to get everyone to change to any other key arrangement.

Many other key arrangements have been tried. Some are claimed to be easier to learn or faster to use than QWERTY. But none has proved good enough to beat QWERTY. It seems that we are stuck with this layout, even if jams are no longer a problem.

QWERTY was developed for the English language. Some other languages use variations. For example, AZERTY is commonly used for French, QWERTZ for German, and QZERTY for Italian. Perhaps you can find someone from India, Thailand, Japan, Korea, or China. Ask them to show you the keyboard they use in their language.

Here’s an AZERTY keyboard, commonly used in France. Nemossos, CC BY

You’ll never regret being able to touch type

Now, on any keyboard, feel the F and J keys carefully and find some tiny bumps. Place your first fingers on those keys, and your other fingers along the same row. Your left fingers should be on ASDF and your right on JKL;. These are called the “home keys”.

Keep your fingers resting lightly on the home keys. Type other letters by moving just one finger up or down and perhaps a little sideways. Learn how to do that quickly, without watching your fingers, and you can touch type!

When I was a teenager, I owned a typewriter. I made a cardboard shield to stop me seeing my fingers as I typed. I used clothes pegs to fix it to the typewriter. Then I found a touch-typing book and started to practise, making sure that I kept my fingers on the home keys and always used the correct finger to type each letter. After lots of practice, I could touch type. I love being able to touch type. It has helped me all my life, first as a student, then in everything I have done since.

Now with computers it’s easier than ever to learn to touch type, even if QWERTY at first seems strange. There’s lots of good software to help (your school may have some), some of it feeling like a game.

Find software that you like, and put in some practice. It may seem hard at first, but persist and you will soon get good at it. Find a friend or two and do it together. Perhaps make it a competition. You’ll never regret being able to touch type.

Children can have their own questions answered by experts – just send them in to Curious Kids, along with the child’s first name, age and town or city. You can:

email curiouskids@theconversation.com
tweet us @ConversationUK with #curiouskids
DM us on Instagram @theconversationdotcom

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