Lesson video

- Oh, hello there, sorry, I was just doing something on my telephone, which is a coincidence because we are going to be learning all about telephones today.

I put my mobile away now, don't worry.

My name is Miss Simkin, and I am going to be teaching you a science lesson today.

In this unit we are learning all about notable and impressive scientists.

And our scientist today is Alexander Graham Bell, and he is so famous because he invented the telephone.

So let's get started and see how he managed it.

Our lesson in question today is who is Alexander Graham Bell? And this is what we're going to cover in today's lesson.

We're going to start with our star words, which is our key vocabulary, then we're going to learn about Alexander's background with deafness.

We're going to do some revision on what sound is, then we're going to hear how he invented the telephone and how it works, and then we're going to learn all about patents.

Don't worry if you don't know what that means yet, because I'm going to explain it to you in a moment.

For this lesson you will need, a piece of paper, a pencil, a colouring pencil so that you can mark your work in a different colour, and a ruler.

If you don't have those things in front of you, could you pause the video and go and get them now please? Great, our star words for today are these, I'm going to say them and then you're going to say them.

Sound, deaf, vibrations, particles, patent, and say that one more time patent.

Good job.

Now let's talk about what these words mean.

A vibration is a rapid movement to and fro, so this is a vibration.

It's a rapid movement to and fro.

Can you have a go at being a vibration for me please? Good job.

Now, sound is vibrations that spread through the air.

When I'm talking, I'm making a sound, and if you put your hand on your throat, do this with me now, and you talk, say something to your screen, say "Hello Miss Simkin." Can you feel that as you're making a sound, your throat is vibrating.

Can you feel those movements, make a noise.

so sound is just vibrations that travel through the air.

Particles are the smallest portion of matter.

Everything is made of particles.

Deaf means being unable to hear, or having impaired hearing.

So it means either you can't hear, or it's very difficult for you to hear.

And a patent is a grant of protection for an invention.

But don't worry, we're going to learn more about that at the end of the lesson.

This is Alexander Graham Bell.

He has got a very impressive beard, and he's a very impressive person.

He was born in 1847 in Scotland.

So we've spoken about this in our star words.

Deaf is being unable to hear or having impaired hearing.

Now this is important to our story of Alexander Graham Bell, because both his mother and his wife were deaf.

And so he was always interested in helping people to hear, and that's what led him to study sound and become a scientist.

So to start with, he actually became a teacher and he became a teacher of deaf people.

And then eventually, because he wanted to help people hear, that's how he was led to develop the telephone, 'cause originally, he was experimenting with sounds and how people hear sounds.

Now, the telephone was one in a series of inventions made by Alexander Graham Bell and also other scientists, that eventually, eventually led to the invention of the electric hearing aid, which is a little device that goes in your ear, and helps you to hear if you struggle with hearing, and that's something that we use today.

So, we are going to draw a timeline to show how those, how the invention of the telephone then led to the invention of the hearing aid.

So can you please on your piece of paper, get your ruler and your pencil and draw a timeline for me so just an empty one to start with like a one on the board.

So a straight line with one, two, three little lines, which is where our three important dates are going to go.

Can you pause the video and do that for me now please? Fantastic.

I'm going to go through each part of the timeline, and after each part, you need to pause the video, and add the notes on the screen to your timeline please.

See the first date on our timeline is 1876.

And this is When Alexander Graham Bell first invented the telephone.

So because Alexander Graham Bell had a few of his family members who were deaf, Alexander wondered if he could make a device that uses electricity to help them hear, and through his experiments, he invented a machine that could send sound from one place to another, and this is the first telephone.

So pause the video and add that to your timeline, please.

Great.

Then, in 1878, so two years later, the inventor, Thomas Edison improved the design of the telephone to make it louder.

And he invented the microphone, that turns sounds into electrical signals, that could travel along wires to a loud speaker.

So pause the video and add that to your timeline please.

Great.

And then, in 1898, so 20 years later, an American engineer called Miller Hutchinson, had a friend who became deaf after catching a disease called scarlet fever, and Miller thought he could use the same scientific ideas as the electric telephone and the, and the microphone to make a hearing aid to help his friend.

So, Miller did experiments with the telephone and the microphone.

And in 1898, he invented the first electric hearing aid.

So now you can pause your video and add that to your timeline please.

Great.

So you can see how each of those inventions builds on the other one.

It starts with Alexander who invents a device called the telephone that can transfer sound from one place to another, then Thomas Edison doesn't just transfer that sound, but he is able to make it louder through a microphone, and then Miller Hutchinson was able to take those ideas of sound travelling as electrical signals, and those electrical signals being amplified to make them louder, to invent a hearing aid, which does that as well.

It takes sounds and it amplifies them so that people can hear.

So you can see that without the invention of the telephone, we wouldn't have got to the invention of the microphone, and then we wouldn't have got to the invention of the electric hearing aid, it's cumulative.

Can you answer this question, please? Why would it be fair to say that the work of at least three scientists led to the invention of the electric hearing aid? So that says at least, because of course, there are lots and lots and lots of scientists, whose inventions have built up over time and their discoveries that have allowed us to do those things, so, for example, without the, the discovery of electricity, we wouldn't be able to have an electric hearing aid, but I just want you to focus on those three scientists that we saw.

Can you pause the video and answer this question, please? Great.

There are a couple of different answers that you could have written for this, but here is an example.

Miller Hutchinson invented the electric hearing aid, but his invention wouldn't have been possible.

Without the work of Thomas Edison, who invented the microphone, and Alexander Graham Bell, who invented the telephone.

It's just one answer, you might have written something different.

But I'd like you now please to pause the video and take a chance to mark your work.

See if there's anything from my answer on the screen that you can add into your answer.

Pause the video and do that for me now, please.

Great.

In the next part of our lesson, we're going to recap the science of sound, so that we have a really strong understanding before we learn how the telephone works.

So sound we learned in our star words is vibrations that spread through the air.

When something makes a sound, it wobbles or it vibrates, and this makes all of the particles touching it wobble and vibrate, and this push gets passed through the air.

So if I make sound, my, my throat is wobbling and vibrating we felt that in the beginning, and the sound is coming out of my mouth into the air and it's making all of the air particles wobble and vibrate and it's this push passes through the air like this in the direction that I'm facing.

Our ears are then designed to sense these vibrations, and tell our brain what kind of sound we are hearing.

So, that's how sound works.

Let's see what you can remember.

Can you answer these questions? sound is that spread through the air.

And when something makes a sound, what happens to the particles in the air? Is it i stopped moving ii they wobble and vibrate or iii they change size.

Pause the video and answer these questions for me now please.

Great, let's mark the answers.

Number one sound is vibrations that spread through the air, and number two particles wobble and vibrate, when something makes a sound.

Pause the video to give yourself to, a chance to tick your answers if you got them correct, or make some corrections if you didn't.

Okay, in the next part of the lesson, we are going to learn about the telephone.

This is a picture of what one of the first telephones would have looked like, looks very different to my mobile phone, and similar mobile phones that you might have seen today.

So the telephone was developed from a machine that already existed called the telegraph, which could send written messages from one machine to another.

But Alexander wanted to be able to send vocal messages, messages of sound.

Alexander first produced a machine that was able to do this in 1876, and the very first sentence that was ever said over a telephone was from Alexander Graham Bell to his assistant, who was called Thomas Watson, and the words that he said were, "Mr. Watson, come here, I want to see you." So these are the first words ever said over a telephone.

I'm going to show you under the visualizer a diagram of how a telephone works.

So I'm going to show you how a telephone works, not a mobile phone that we mostly use nowadays, but a telephone that's connected to wires like the first telephone that Alexander Graham Bell used.

So a telephone, has two main parts, it's got the loudspeaker, where sound comes out, and the microphone, Where sound goes in.

Now, a telephone, is connected, to another telephone by miles and miles and miles of wire.

So I've only drawn a short wire here, 'cause I've only got a short whiteboard, but there will be miles and miles and miles of wire in between this, and this is how it works.

A sound is produced, so somebody says something and it goes into the speaker on the first telephone.

This microphone changes that sound into an electrical signal, an electrical signal.

That electrical signal then travels through the miles and miles and miles of wire to the other telephone, where this loudspeaker changes it from an electrical signal back into a sound.

And that's how a telephone works.

So the sound comes in, gets changed to electrical signal, travels along the wire, and then comes out as sound.

Draw your own diagram to show how a telephone works.

Please remember to add labels just like I did under the visualizer.

Pause the video and do that for me now, please.

Great, now we're going to learn the last part of the story about the invention of the telephone.

So we spoke at the beginning of the lesson about a patent.

And it's a grant of protection for an invention.

If you own the patent for an invention, then it gives you the right to stop somebody else from making or selling your invention without your permission.

So, for example, if I invented the telephone, I would want the patent for the type of patent, for the telephone, so that nobody else could say that they invented it, and nobody else could make money off it without asking me.

It can sometimes be quite hard to find the true inventor, because inventing is quite a tricky business.

And sometimes credit can go to the wrong person, or the person who has the best working version of something, or just the person who gets to the patent office most quickly, which is what happened with the case of the invention of the telephone.

So here are some of Alexander Graham Bell's notes.

So you can see he's got a diagram there of the first teller teller telephone.

So he definitely did invent the telephone.

We're not questioning that.

But there's a bit of controversy over whether he was actually the first person to invent it.

So this is a scientist called Elisha Grey.

And he applied for a patent for the telephone on the same day as Bell.

These scientists didn't actually visit the office themselves, the patent office, but their lawyers went on their behalf.

And it's thought that Bell's lawyer got there just before Elisha Gray's lawyer, and so Bell was given the patent for the telephone.

However, some authors and some historians dis=speak this and think that there might have been some dodgy behaviour going on at the patent office or possibly even by Bell himself.

Could you imagine being Elisha Grey, and being only like half the day, away of getting all of the credit for inventing the telephone when you did just as much work as Alexander Graham Bell too? It will be pretty tough.

Can you answer these questions, please? What is the patent? And who else invented the telephone and why didn't they get a patent? See if you can do it from memory.

If you're finding it tricky, that's okay.

Just go back and watch the last couple minutes of the video again, and then have a go.

Pause the video and answer these questions now, please.

Great, let's mark our answers.

So a patent is a grant of protection for an invention.

Or you could have said a patent is something that stops anybody else from being able to use ,to use your, or your claim your invention.

And number two, it was Elijah Grey, who invented the telephone as well, but he did not get the patent, because Alexander Graham Bell's lawyer beat his lawyer to the patent office.

If you need some more time to mark your answers, pause the video and do that for me now please.

Great job today, well done for all of your hard work, you have been fantastic.

If you would like to share your work with Oak National.

Then you can ask your parent or your carer to share your work on Twitter, Instagram, or Facebook and tag Oak National and #LearnwithOak.

You can also tag @teach_STEMinism, which is me and then I will be able to see your work too.

Don't forget to complete Your End of lesson quiz, and have a fantastic rest of your day, and hopefully I will see you back here soon, for another science lesson.

Bye, everybody.