micro:bit: Mission to Mars - Live Lesson: Additional video clips

Fran Scott:
Okay, so we've heard why space travel is so important, and why scientists are really interested in life on Mars. But how much do you know about the planet itself?

Ed Petrie:
Time to get those brains in gear, and you in the classroom as well, because we've got some questions now. So, why is Mars called the red planet?

Female student:
Because there's like red rocks over there and there's volcanoes and it's close to the sun.

Ed Petrie:
Okay, well loads of reasons there. Why do you think it's called the red planet?

Female student 2:
Is it called the red planet because it has red rocks?

Ed Petrie:
Okay, red rocks seems to be quite a popular answer, is that right Fran?

Fran Scott:
Do you know what, that is pretty right. Mars was given the nickname the red planet, not because it's hot, which some of you might think, but because yes, it looks red to the naked eye. And that is because of the rocks. The rocks on the surface of Mars, they contain iron, and when the wind blows, dust from those rocks is thrown into the air and the iron in those dusts reacts with oxygen, creating iron oxide, or rust, and that is orangey red.

Ed Petrie:
Right, okay, here's another one. Question two, how many moons does Mars have? Answer, answer now!

Male student:
Okay. Because the scientists are trying to find if there's water on the moon, if there was no moon, the water would just fly away because…

Ed Petrie:
Right, so but how many moons are there?

Male student:
Maybe one.

Ed Petrie:
Maybe one. Very precise scientific answer there. How many moons do you think Mars has got?

Male student 2:
I think there's two.

Ed Petrie:
Two. Okay, so we're going with one, maybe one, maybe one or two, what do you think Fran?

Fran Scott:
Well, the answer is actually two. Mars has two small moons and they're called Phobos and Deimos, and those words mean fear and panic. And they are named after the horses that pulled the chariot of the mythological war god Mars. So it makes sense.

Ed Petrie:
Yeah, it makes sense so me. Now, question three, how many humans have been to Mars. How many do you reckon?

Female student 3:
Six?

Ed Petrie:
Six. Six humans you're going with, okay. How many people do you think have been to Mars?

Female student 4:
None.

Ed Petrie:
None. Oh okay, two very different answers there. Six or none. How many Fran?

Fran Scott:
The answer is actually none. No humans have actually set foot on Mars. We have though sent 20 spacecraft to the planet, and robotic explorers, or rovers as we call them. They have been studying the surface for more than 40 years. But as of yet, there's been no humans.

Ed Petrie:
One thing is for sure Fran, you can't get into space without a rocket. Now, worksheet one at the ready everyone, because I feel the need, the need for speed. And while the studio is just a wee bit small to launch a proper rocket, we do have a rocket car in the studio. Please welcome Mike Ford, engineer at The Bloodhound Project, to tell us about his rocket car. [APPLAUSE]

Ed Petrie:
Hi, you alright?

Mike Ford:
Hi Ed.

Ed Petrie:
Now I do spot a little rocket looking car thing over there, is that yours? It's a bit small.

Mike Ford:
It is ours Ed, but that's a one tenth scale model. We can't drive that.

Ed Petrie:
No, it'd be ridiculous.

Mike Ford:
We wouldn't get the real car in here. 13.2 metres long, over seven and a half tonnes fully fuelled. There's the image of the real car.

Ed Petrie:
OH wow.

Mike Ford:
Okay? That's bigger than a double-decker bus.

Ed Petrie:
That is quite a monster.

Mike Ford:
It certainly is.

Ed Petrie:
So what makes it a rocket car? Presumably it's got a rocket.

Mike Ford:
Yes, our car has a jet, it has a rocket. You know, it's designed, that car is designed to break the land speed record. Okay? It's going to travel at speeds in excess of 1000mph. So with a rocket on there, as everybody knows, a rocket to get to space has to travel exceptionally quickly, and our rocket in our car has got to do the same thing. So the similarity is there. We want that rocket to develop maximum power in the shortest possible time.

Ed Petrie:
And what part does coding play in the design and the operation of something like your rocket car?

Mike Ford:
Well two things spring to mind. Look at the shape of that car. Very aerodynamic. The shape has been developed using computer modelling. If a person had done that particular task, it would have taken a person over 50 years. So you know, thumbs up for computers on that one. And also, our car is controlled by computers. We have three computers on board, one for jet, one for rocket, and one for vehicle systems. And they're all interlinked and coded together, so they make that car work. So coding, again, very, very important for us.

Ed Petrie:
And am I right in thinking that you're getting kids in schools to actually design their own rocket cars, albeit on a smaller scale?

Mike Ford:
On a smaller scale, absolutely. We're currently in the middle of a model rocket car challenge. We've issues 10,000 kits to schools and we've actually engaged with 3000 teachers on our platform bloodhoundblast.com so yes, we're doing it, we're in season one at the moment, we're just about to move to season two later on this year, where we'll also include primary schools as well.

Ed Petrie:
Wow, that's a lot of rocket cars. Fran?

Fran Scott:
I'm actually with one of those schools right now, you guys are from the Kennet School, right? And I've got Adam, Emma, and their teacher Mel, and you guys have designed your own rocket car, haven't you? So Emma, could you tell me a bit about how you went about designing the car?

Emma:
Well to make it as streamlined as possible, we put a point at the front, and to, you have to make sure you put no flat surfaces at the front to reduce air resistance.

Fran Scott:
So you keep it pointy so it can cut through the air? Nice work, and Adam, what speeds did you car go up to?

Adam:
Our car actually managed to reach speeds up to 65mph.

Fran Scott:
65mph. That is pretty fast.

Fran Scott:
Well I think it's about time that we race some rocket cars, what do you guys think? [CHEERS]

Fran Scott:
So Mike, are we going to be using the micro-bit here to measure the speed?

Mike Ford:
Yeah, we are. We have a little setup here, which is our timing gate, and as probably hopefully everybody knows, speed, you can work out speed if you know distance and time.

Fran Scott:
Right, cause speed is distance divided by time.

Mike Ford:
Divided by time, absolutely correct. And we have an inlet gate here, so we have an infrared transmitter receiver set up here. Here is the micro-bit, as you can see, the micro-bit is displaying time here. And then we have an outlet gate there, again, an infrared device and a receiver. So the car enters the inlet gate, starts the clock, exits the outlet gate, stops the lock, and the time is displayed on the micro-bit in milliseconds.

Fran Scott:
Brilliant, and these gates are like light beams that they cut.

Mike Ford:
Absolutely, yes.

Fran Scott:
Perfect.

Mike Ford:
That's the way it works.

Ed Petrie:
Well we're actually going to be racing three different shaped rockets this morning, so while we prepare for launch, we want you to have a think about which of our three designs will hit the fastest speed. So think about which of these shapes might be more aerodynamic and why. So design one is a fetching red color, with a rounded nose shape, and a racing car style fin. Design two has a lime green and orange colour palette, with a pointed nose shape, and a basic fin design. And finally, design three, a flashy little blue and orange number, with a larger nose cone and tail fin. So which colour do you think will go fastest, red, green or blue? What do you think guys?

Audience:
Green!

Ed Petrie:
Nearly everyone shouted out green. [LAUGHS] Well, you really love the colour green, okay. Well let's find out, shall we? Can we fire the rockets?

Mike Ford:
Yes, let's get back to a safe distance guys.

Fran Scott:
Yes please.

Mike Ford:
And Jazz, I'm happy.

Jazz:
Yep, check live.

Ed Petrie:
Okay, here we go. Three, two, one, launch.

Fran Scott:
So we told you that was fast, but here's a reply that we shot earlier in slow motion. So how fast was that one Mike?

Mike Ford:
108 milliseconds.

Fran Scott:
So that was 108 milliseconds, and here, the smaller the number, the faster the car. So Mike is just resetting there. And I think we're ready for the second.

Mike Ford:
We're ready for the second.

Fran Scott:
Let's launch another car.

Fran Scott:
So we're just resetting the micro-bit there.

Mike Ford:
There we go.

Fran Scott:
So we can measure the new speed.

Jazz:
Check live.

Ed Petrie:
Three, two, one, launch!

Fran Scott:
Ooh. Let's see what speed that did. 84, was that?

Mike Ford:
84.

Fran Scott:
Yeah, so that's 84 milliseconds. So that is faster than the red car. So we'll see what the third one can do. This is working quite well. And we're ready for the third.

Ed Petrie:
Are we ready?

Jazz:
Check live.

Ed Petrie:
Okay, here we go. Three, two, one, launch.

Fran Scott:
Ooh. Got a nice pile of cars there. And what speed was that? That was

Mike Ford:
96.

Fran Scott:
96 milliseconds. So I think we do have a winner though Ed, don't we?

Ed Petrie:
We do, you'll be pleased to know everyone, it was the green car. [APPLAUSE] Well done, you virtually all got it right.

Fran Scott:
Well done, and here to explain the coding behind our speed gate, please welcome our resident coder, Amy Mather. [APPLAUSE]

Fran Scott:
So Amy, can you tell us a little bit about how that code worked and we measured the speed with it?

Amy Mather:
Yeah, so earlier Mike mentioned the equation speed equals distance over time. So we already know the distance, which is one metre, and we need to work out how long it took the car to travel that one metre. So if you look over here in our code, we've got a couple of variables. So the first variable we've got is start time, and you can see here that the light gates that are over there are connected to two different pins on the micro-bit. So the first light gate is connected to pin two, and when it's triggered then the start time variable is set to the current time. And then when the second light gate is triggered, then the current time is, the start time is taken away from the current time, and then we can find the total time taken, and from that work out the speed in metres per second.

Fran Scott:
Genius, and are there other things that you can use this code for?

Amy Mather:
Well yeah, so if you've got the light gates at home, you could use it to measure the speed, how fast your dog could run.

Fran Scott:
[LAUGHS] Brilliant.

Amy Mather:
How fast you and your friends could go on a skateboard, or maybe even how fast you could kick a football.

Fran Scott:
Oh Amy, brilliant as always, thank you ever so much.

Amy Mather:
Thanks.

Fran Scott:
Of course getting of the ground is just the beginning of your microbit's mission to Mars, and the most dangerous part of any space journey is takeoff. But as you hurtle through space, there is no end of things to get in your way.

Ed Petrie:
Exactly, so what sort of obstacles do you think you've got to look out for when you're launching your rocket?

Female student 1:
Like what's in front of you when the rocket is being launched, and how fast you're going to be, because you're going to need to be fast if you want it to launch really good.

Ed Petrie:
Okay, and so you're heading out into orbit, into space, what do you think you've got to look out for up there?

Female student 2:
The rocks, just in case like you land on a rock or something.

Ed Petrie:
Right, yeah, there's probably some rocks floating around up there. What I was actually looking for was space junk. So that's bits of rockets, bits of satellites, bits of shuttles, all floating around up there, getting in the way. And Josh, how much of a problem is space junk?

Josh:
Well space junk's a huge problem because as you said, you've got all these bits of rock that we find out in space anyway, plus all the satellite pieces that we've launched up there that are floating around, and if they're going to collide with something, whether that's a rocket taking off or an astronaut that's already up there, they could cause a huge problem for anything they collided with.

Ed Petrie:
So what's the solution Josh?

Josh:
Well we don't really have a good one at the moment. We kind of try and bring things back where we can, but a lot of it stays up there. There's lots of different ideas though, some scientists are looking at lasers that could vaporise the debris that's up there.

Ed Petrie:
Lasers?

Josh:
Yeah, big magnetic nets to catch it all and bring it back to earth. There's even been some ideas for little spacecraft that could go up, collect the debris and bring that back safely. But it's important that we figure out how we do that. Now coding helps us, because we can track all of these objects that are flying around space. So we program big computer programs to keep an idea of where they are. Because if there's a collision course with, say the International Space Station, like we saw recently with Tim and his damaged window, we can actually move the astronauts out of the way, to keep them safe.

Ed Petrie:
OH right yeah, because they've got to be quite careful, haven't they, because am I right in thinking that in space, your reaction times slow down? So if you see something like that coming towards you, you're not necessarily going to operate at maximum efficiency.

Josh:
Yeah, so this is where that tracking comes in handy. It means that we can keep an eye on it and give them plenty of notice, because your reaction times do slow down in space, and we're not sure why yet. Now it's something we've been testing at the moment. In fact Tim Peake's up there with a small mini computer, a bit like the BBC micro-bit, but it's actually got some reaction games on that's been programmed by schoolchildren, and measuring his reaction time, they're going to measure those once he gets back to Earth, to see how it changed while he was up there.

Ed Petrie:
So he gets to play games while he's up there as well? Not only is he an astronaut, he gets to play games? Lucky old Tim Peake. And you're saying it's not just human beings dumping all their rubbish up there, it's also meteorites as well.

Josh:
Yeah, there's also lots and lots of space rocks, and I've got a bit of a treat for you today, because I've actually brought with me a space rock. So this is a meteorite that fell to Earth quite a while ago. It's probably the oldest rock you'll ever touch there. That was once upon a time up in space, and hurtled its way down to Earth, probably with a bit of a bang when it landed.

Ed Petrie:
Fran, I'm holding a bit of meteorite. I've got something from space!

Fran Scott:
[LAUGHS] I'm so jealous of that. And it would be so scary, floating around space with those meteorites zooming past you on their way to Earth. So you want to make sure your reaction time is as quick as possible, which is where we come in to help, because we have a game you can play on your micro-bit to help sharpen up your reaction speeds. So it's time to turn your attention to worksheet two. And have you guys in the audience all had a chance at playing your meteorite game, yeah? Yeah? Good. Well because this time Ed, you're going to give it a go.

Ed Petrie:
Okay.

Fran Scott:
So we've got a micro-bit just here, but so the audience can see what's going on, I've got my giga-bit right here.

Ed Petrie:
I'd have a hard time fitting that in my pocket.

Fran Scott:
You would do, but it repeats what you are doing. And this game could not be simpler. So you've got your A and you B buttons, and they're like your left and right. So what you need to do is use those to avoid the meteorites as they're coming down through Earth, and you need to avoid them just by moving left and right. Think you can do that?

Ed Petrie:
Oh yeah. Easy.

Fran Scott:
Okay, let's start the game.

Ed Petrie:
Okay, here we go, so it's a bit like Space Invaders.

Fran Scott:
It is a bit like Space Invaders. So you've avoided one.

Ed Petrie:
See, I told you it was easy.

Fran Scott:
You're doing quite well. And you've avoided another one.

Ed Petrie:
Oh hang on, is it speeding up, or is that just me?

Fran Scott:
It does, it gets more and more difficult as time goes on.

Ed Petrie:
Doh!

Fran Scott:
[LAUGHS] So that is game over. But for now, because what I want to do is see how you cope like an astronaut, because like we were saying, astronauts, they've got to have really quick reaction times, even when they're getting distracted .

Ed Petrie:
Right…

Fran Scott:
So I want you to try it again, but this time, I want you to keep one eye on the big screen, and you'll see big brown things coming towards you.

Ed Petrie:
That doesn't sound very good. [LAUGHS]

Fran Scott:
[LAUGHS] It doesn't. But they are meteorites. So every time you see a meteorite, I want you to shout, meteorite.

Ed Petrie:
Oh, okay.

Fran Scott:
But they might not be coming just from the screen, because do you guys have your meteorites ready? Yeah?

Ed Petrie:
Oh no, I don't like the look of this. [LAUGHS]

Fran Scott:
Hold on to them for now, and wait till I tell you. Okay. Are you ready Ed?

Ed Petrie:
Yeah, I think so. Okay.

Fran Scott:
Let the game begin.

Ed Petrie:
Okay, here we go. Okay, right, meteorite!

Fran Scott:
Throw your meteorites!

Ed Petrie:
Meteorite! Ow, get off! Ow! Meteorite!

Fran Scott:
Oh no, game over. Game over Ed, game over.

Ed Petrie:
I got one.

Fran Scott:
You did. [LAUGHS]

Ed Petrie:
Oh what? That's not fair, you put me off, Right, I'm having another go, I'm having another go.

Fran Scott:
Well I am here with our resident coding expert Amy Mather to show how that game works and how we've coded it, because there's lots of different elements to it, isn't there? It seems simple but perhaps it's not.

Amy Mather:
So the code is slightly more complex than the game. So what we've got here is something that might be new to you. So we've actually used function within this code. So you can come over here and you can look through all the different functions. And what a function basically is, is say your teacher is teaching you something new in maths, like I don't know, long division, they'd teach you a method which you could then apply to different numbers. So the way that a function works, is that you create an almost method which you can then apply to different situations within your code. So it helps you to kind of give a little bit more structure to your code and perhaps stop you from repeating yourself, or make it a little bit clearer.

Fran Scott:
Brilliant, so it makes your code shorter, but still includes all of the elements that you want to.

Amy Mather:
All the important elements that you need. Yeah, exactly.

Fran Scott:
Well as always Amy, thank you very much indeed.

Ed Petrie:
So you've got your rocket off the ground, you've navigated your way through space, you've landed on Mars. Now what? How do humans live there? What do you think are things that you need to live on another planet, what are the essentials?

Female student 1:
Food and water and a bed.

Ed Petrie:
A bed. [LAUGHS] Take lots of beds up to Mars. And duvets?

Female student 1:
Yeah.

Ed Petrie:
Yeah, a nice duvet. What do you think you'd need for living on another planet, what are the essentials?

Female student 2:
Probably food and water like she said…

Ed Petrie:
Food and water's pretty important. Yeah, we all love a bit of food and water.

Female student 2:
And plants so you can get…

Ed Petrie:
Plants, interesting. Yeah. Because I don't think there's a lot of plants on Mars by all accounts, are there? Have you got any ideas?

Female student 3:
Maybe food and water, and a fan because it's really hot there.

Ed Petrie:
[LAUGHS] A fan. Yeah, I'm not sure if you'd feel that through your space helmet. Does Mars have the essentials for life Fran?

Fran Scott:
Well that Ed is the million dollar question. And one that teams of scientists are busy trying to answer right now. So I want to introduce you to a flashy bit of kit. He is very cool. This is Bruno, the Mars rover, or you can call him Bruno Mars for short. Oh look at him. Isn't he beautiful? Now Bruno here, he is the first European rover, and a similar design of rover will actually be sent to the red planet in two years' time. And on board of Bruno is a tiny science lab, and it's shrunk down so it fits on the back of him. And that's got the ability to undertake lots of different experiments. And one of Bruno's key missions is to break up the rock on Mars, dig down below the surface, and go in search of signs of life. And he has so many tools to help him do this, including one tool that will test for things like DNA and protein. And he goes these wheels here, and he's got, oh he's brilliant.

Ed Petrie:
Sorry Fran, sorry, I'm going to have to stop you there. We've got some breaking news from BBC Mars 24. BBC science correspondent and rove report Pallab Ghosh has an update.

Pallab Ghosh:
This news just in. Satellite pictures show that there were once tsunamis on the Martian surface, suggesting that there was once an ocean four and a half billion years ago. This indicates that Mars was once like Earth in the distant past, harbouring life. And what's really exciting is that the water from the ocean is probably still there, deep under the surface, frozen, and that could indicate that there could still be life there, waiting to be discovered.

Ed Petrie:
Josh, how exciting are these developments?

Josh:
These developments are thrilling, you know, this is why we send rovers and things like this to explore Mars, because we find out these things. And the reason it's so impressive is because it completely changes our understanding of Mars. When we look at Mars, we think about it being very rocky and dusty and dry, and pretty dull. But actually it turns out it was much more exciting. We see examples of tsunamis. We see examples of rivers and lakes and seas, and we know now from what we've understood, that a long time ago, Mars was very wet, and very different. Now one really interesting fact is that from here on Earth, we've discovered anywhere there's liquid water, even just the tiniest drop of it, we generally tend to find life. So that massively increases Mars' chance for maybe harbouring aliens.

Ed Petrie:
Wow, that's incredible. And if they are there, then Bruno could have a pretty good chance of finding them, because he's quite an impressive bit of kit, isn't he?

Josh:
He is, and this is exactly why we're building these things. We're sending them off there to find out what Mars is like. And one of the good places to look for life or the evidence of life on Mars is actually beneath its surface. Mars doesn't have a particularly thick atmosphere to protect it from the sun, so we think a lot of life that may have existed, if it did, or if it still does, might be beneath the surface. So Bruno's going, with the equipment to be able to drill and look beneath its surface and find out. And Bruno is a fantastic piece of equipment that relies on coding, because he can actually drive himself, like a lot of the new generations of rovers. Rather than being programmed their path exactly, instead the rover themselves looks for where they are, looks for rocks that might get in the way, and plans their own route, a bit like a sat nav that could drive itself.

Ed Petrie:
Wow, that's amazing. And talking of the surface of Mars, I don't quite understand how this is possible, but someone told me that you carry a little bit of the surface of Mars around with you. That can't be true.

Josh:
We are a little bit closer to the surface of Mars than you might have thought, because I do happen to have a piece of Mars in my pocket.

Ed Petrie:
No.

Josh:
This actually fell to Earth about 100 years ago, landed over in Egypt, and this has probably been knocked loose by maybe a meteorite impact on the surface of Mars, big enough to knock material out into space that's eventually drifted its way over to the Earth. So this is a little tiny fragment of the surface of Mars, not the entire meteorite. The entire meteorite was a little bit bigger. But it gives you a chance to have a look and see what it looks like, and surprisingly, it's not red as we would have expected, and that's because only the surface rocks tend to be red. Whereas most of the rock down there is pretty much the same as our rock down here.

Ed Petrie:
So what is that? What kind of mineral is it?

Josh:
So there's a lot of iron in there, which is what then gives it the rust, so if we expose it to the air, ti would rust up and things like that, and all sort of other materials as well that we find up on the surface of Mars. And it's actually the materials that we find in there that help identify it as a piece of Mars, and not just a speck of dirt that I've picked up to try and trick you.

Ed Petrie:
[LAUGHS] Yeah, I trust you, I trust you Josh. Look at that, I'm holding a piece of Mars.

Fran Scott:
I can't believe we actually have Mars in the studio. That's brilliant. We're not going there, it's coming to us. But I am really interested in life on Mars, and if you are as interested in finding life on Mars as I am, I've got another idea for you right now. How would you guys like to try some alien life detective work? Give me a yeah?

Audience:
Yeah!

Ed Petrie:
Yeah.

Fran Scott:
You would, I'm sure you would. And as we've been saying, there's a Mars Curiosity rover at the moment on planet Mars, and it's busy testing for life up there. And one of the best ways to detect for life, is by testing for carbon dioxide, because everything breathes. So everything that does breathe, we call aerobic. And when it breathes, it releases carbon dioxide, or CO2. And it just so happens, I have a little bit of kit here, that uses a micro-bit and detects for levels of CO2. Check out my alien life detector.

Ed Petrie:
Wow, looks like something out of Doctor Who.

Fran Scott:
Look at it, it's brilliant, with the little micro-bit here. So I was thinking, I know you like a little bit of tomfoolery.

Ed Petrie:
Oh yes, renowned for it.

Fran Scott:
So I was thinking, we could try a little bit of a game. So I've got my Martian landscape over there. And there's three different places you can hide. So I'm going to look away, I want you to choose a place to hide, and then I'm going to use my CO2 detector, to try and work out which hiding place you are in.

Ed Petrie:
I'm master of disguise Fran. You've got your work cut out.

Fran Scott:
You are, I'm a master of science, so we'll see.

Ed Petrie:
Okay, alright, I'm hiding. I'm hiding. Still hiding. Still hiding.

Fran Scott:
Are you hidden yet?

Ed Petrie:
I am well and truly hidden.

Fran Scott:
Okay. So I'm going to go over to the first hole. This is the first box, oh those meteorites get everywhere. If I Just put it down the hole, then what happens is it's detecting how much carbon dioxide is there, and when it detects a high level, it will make a sound. So it's not in there, I don't think you're in box one. Nope, but we have a pig. A stuffed pig. Not breathing therefore not releasing carbon dioxide. Box two? Let's give it a go. Are you in box two? I think you're in box two, we hear the alarm. So Ed… Hello.

Ed Petrie:
Oh, rumbled. So comfy in here.

Fran Scott:
Yeah, I bet it's not. But what we're going to do is again, go over to our resident coding expert Amy Mather, who can help explain the coding behind our gun here. So Amy, how does this alien detector, how does it work, because there's lots of different sensors aren't there, that people can do at home, to attach onto their micro-bit.

Amy Mathew:
Exactly. So what you've got there is a CO2 detector, but what we've got here is a variety of different sensors. So this one here is a moisture sensor. And this one here is a motion sensor. This one here is an LDR, or a light dependent resistor. And this one is a thermistor, or a temperature sensor basically.

Fran Scott:
Right, so we've got moisture, movement, light…

Amy Mathew:
Heat.

Fran Scott:
Right, so four different ones.

Amy Mathew:
Yeah, so we can demo the moisture one first. So if you want to, so if we hold it out here, and first of all we can, hopefully the air's going to be quite dry.

Fran Scott:
And it shows us that on the screen.

Amy Mathew:
Yeah, so it tells us

Fran Scott:
That's pretty awesome.

Amy Mathew:
And then…

Fran Scott:
Dip it in?

Amy Mathew:
Yeah. So unsurprisingly, the water has a reading of wet. [LAUGHS]

Fran Scott:
[LAUGHS] So it goes from dry to wet. Brilliant. And do you have another one that you can show us?

Amy Mathew:
Yeah, so over here we've got a light sensor connected up to an RGBLED essentially. So what we can do…

Fran Scott:
So RGB is red, green, blue.

Amy Mathew:
Yeah, red, green and blue. So all light is made up of three lights, which is red, green and blue.

Fran Scott:
So that means it can change colour.

Amy Mathew:
So you can change the colour. So if you want to press the buttons, then we can change the colours.

Fran Scott:
Underneath?

Amy Mathew:
So underneath, just press one or the other.

Fran Scott:
I'm going to go for this one.

Amy Mathew:
Yeah, and press again and then it will continue to change.

Fran Scott:
Nice, so it changes through all the colours of the spectrum, all the colours of the rainbow. Nice.

Amy Mathew:
And what you can also do is you can diffuse the light using either acrylic, or you can create paper templates and things like that, and there's a tutorial on the website, if you want to find out more.

Fran Scott:
Brilliant Amy. I love these sensors, and it helps us to react with the real world, doesn't it? We're attaching them on to these parts?

Amy Mathew:
The GPIO pins, along the bottom of the micro-bit, are the general purpose input output pins. And basically it's like the micro-bit's door to the outside world, where it can get information from the outside world, but also post information out to the outside world.

Fran Scott:
Perfect, so coding is not just computer based, it can help you react with objects around you as well.

Amy Mathew:
Exactly.

Fran Scott:
Brilliant.