0:00:36 > 0:00:41So what I've done is fit it with a 3D holographic laser projector.
0:00:41 > 0:00:43It is astonishing.
0:00:43 > 0:00:47Trust me, my little lab rat friend, this is no ordinary watch.
0:00:47 > 0:00:51Mind your eyes. This could be bright. Here we go.
0:00:53 > 0:00:54Oh...
0:00:54 > 0:00:57Yeah, on second thoughts, this is an ordinary watch.
0:00:57 > 0:01:01I've lost my 3D holographic laser one.
0:01:01 > 0:01:03Go away. Hello. I'm Richard Hammond.
0:01:03 > 0:01:05Welcome to my Blast Lab.
0:01:05 > 0:01:07APPLAUSE
0:01:10 > 0:01:13I'll get another one. I can't begin to tell you
0:01:13 > 0:01:17about some of the exciting experiments we do here.
0:01:17 > 0:01:20No, really, I can't, because if I start to tell you about them
0:01:20 > 0:01:22the Government gets quite cross.
0:01:22 > 0:01:25Nevertheless, I do occasionally like to invite two teams
0:01:25 > 0:01:27of young scientists here to take part
0:01:27 > 0:01:30in exciting scientific challenges and compete for great prizes.
0:01:30 > 0:01:34So, coming up, we have Oliver helping us navigate our way
0:01:34 > 0:01:35through some fascinating facts.
0:01:39 > 0:01:42In Mini Science, we try to prevent a leak.
0:01:46 > 0:01:49My lab rats apparently travel back in time
0:01:49 > 0:01:53to try and beat the javelin world record. We'll see about that.
0:01:55 > 0:01:58It's time to get ultra messy.
0:01:58 > 0:02:00It's Snot Wars.
0:02:05 > 0:02:08Now, for a top-security lab, you need a top-security guard
0:02:08 > 0:02:10and this lady is right at the very top of the table,
0:02:10 > 0:02:15especially when it's ranked by age, because it is my Ninja Nan.
0:02:22 > 0:02:26It might look like she's asleep, but in fact she's meditating.
0:02:26 > 0:02:29It's part of her martial arts training.
0:02:29 > 0:02:31It helps her to focus her positive energies.
0:02:31 > 0:02:34Or, actually, no, maybe she is sleeping.
0:02:34 > 0:02:38OK, let's have a look at who's trying to get into my lab today.
0:02:43 > 0:02:45Hello.
0:02:45 > 0:02:49Now, you've come along here claiming to be the Red Team.
0:02:49 > 0:02:51I'm here to check you through security.
0:02:51 > 0:02:55- Your names, please?- Iffy.- Sky.- Ruth.
0:02:55 > 0:02:58Iffy, Sky, Ruth. Yep, OK, that sounds about right.
0:02:58 > 0:03:02Under "talent", it says you're going to do something
0:03:02 > 0:03:03to prove you are the right people.
0:03:03 > 0:03:08- We can do a crab.- Yeah, that's what it said here. Go on, then, do one.
0:03:10 > 0:03:12Whoa! They're broken!
0:03:12 > 0:03:14That's terrifying. OK, fair enough.
0:03:14 > 0:03:16You are the Red Team. Come on into the lab.
0:03:16 > 0:03:17APPLAUSE
0:03:21 > 0:03:24OK, welcome to the lab. You're past Ninja Nan,
0:03:24 > 0:03:26but you've only got this far
0:03:26 > 0:03:29because we agreed a password with the real Red Team.
0:03:29 > 0:03:32If you are the real Red Team, you'll know it. What is it?
0:03:32 > 0:03:35- Carwash.- Yeah, that's what I've got written down here.
0:03:35 > 0:03:37Why did you pick that?
0:03:37 > 0:03:39Because I've got a phobia for carwashes.
0:03:39 > 0:03:43OK, fair enough. If anybody sees a carwash sneaking up on her,
0:03:43 > 0:03:44we'll let you know.
0:03:44 > 0:03:46Welcome to the Blast Lab.
0:03:46 > 0:03:51Go and get settled in ready for the first round. Our Red Team!
0:03:51 > 0:03:54Right, let's meet the bunch of people
0:03:54 > 0:03:56claiming to be the Yellow Team.
0:04:01 > 0:04:04Nice to see you, standing there looking pleased for yourselves.
0:04:04 > 0:04:07However, before I let you into the Blast Lab, we have to be sure
0:04:07 > 0:04:10you are who you say you are. Identify yourselves, please.
0:04:10 > 0:04:12- Lewis.- Josh.- James.
0:04:12 > 0:04:15Yep, that's what I've got written down here.
0:04:15 > 0:04:18Talent. What are you going to do for us?
0:04:18 > 0:04:23- I can tell jokes.- Really, Lewis? It's a high-risk strategy. Go on.
0:04:23 > 0:04:25What's the most musical fish?
0:04:25 > 0:04:28The most musical fish? I don't know.
0:04:28 > 0:04:30A piano tuna.
0:04:30 > 0:04:33That actually physically hurt. Just in case you try
0:04:33 > 0:04:36telling any more, we'll let you in. Come through.
0:04:36 > 0:04:37APPLAUSE
0:04:40 > 0:04:43Very nice, very nice. It was nearly a joke.
0:04:43 > 0:04:45I mean, really, nearly.
0:04:45 > 0:04:48Chaps, we've agreed a password with the real Yellow Team
0:04:48 > 0:04:49and I'll need that from you.
0:04:49 > 0:04:53- Wheels.- That's what I've got written down here. Why wheels?
0:04:53 > 0:04:55Because we all like to cycle.
0:04:55 > 0:04:57How lovely. But of no use here in the Blast Lab.
0:04:57 > 0:05:00We don't allow bicycles. The lab rats are scared of them.
0:05:00 > 0:05:03Let yourselves in, go and get ready for the first round.
0:05:03 > 0:05:05The Yellow Team!
0:05:05 > 0:05:06APPLAUSE
0:05:07 > 0:05:10He has several diplomas and quite a lot of parking tickets.
0:05:10 > 0:05:12I'm talking of course about Oliver!
0:05:12 > 0:05:13APPLAUSE
0:05:30 > 0:05:35Welcome, Oliver. Get him docked up to the Fact Nav.
0:05:35 > 0:05:37Hold on. Connect him up. There we go,
0:05:37 > 0:05:39right, plumbed in.
0:05:39 > 0:05:41Actually, they did recently
0:05:41 > 0:05:44develop an upgrade for Oliver's Fact Nav system,
0:05:44 > 0:05:48but rather than spend money on that I decided to program it myself.
0:05:48 > 0:05:53Turns out to be really, really, really amazingly difficult
0:05:53 > 0:05:55to upgrade software yourself like that.
0:05:55 > 0:05:56So, as a result, some of the facts
0:05:56 > 0:06:00that I have here are not true and some are.
0:06:00 > 0:06:03It's up to you teams to tell me which are true and which are false.
0:06:03 > 0:06:06Oliver will then let us know. If it is true, he'll do this.
0:06:06 > 0:06:07WHIRRING SIRENS
0:06:09 > 0:06:11However, if it's false, he'll do this.
0:06:11 > 0:06:13DEEP HORN
0:06:13 > 0:06:17The game is pretty simple. Each team has three lights.
0:06:17 > 0:06:19All three are lit red.
0:06:19 > 0:06:21When you answer a question correctly,
0:06:21 > 0:06:23one of your lights will go green.
0:06:23 > 0:06:26The winning team is the first to get three lights lit green.
0:06:26 > 0:06:30Just one slightly cruel complication,
0:06:30 > 0:06:32which is, if you answer correctly,
0:06:32 > 0:06:34your light goes green. Great.
0:06:34 > 0:06:37If you answer it incorrectly, you don't get the green light -
0:06:37 > 0:06:40the other team does, which means you can get it wrong and you can
0:06:40 > 0:06:42actually win it for the other team.
0:06:42 > 0:06:45So think carefully about your answers.
0:06:45 > 0:06:47To get the game going and see who seizes control
0:06:47 > 0:06:51right from the very start, we begin with a "nearest to" question.
0:06:51 > 0:06:53I'll award the green light
0:06:53 > 0:06:56to the team that gets nearest to the real answer.
0:06:56 > 0:06:58They will get the first true or false fact.
0:06:58 > 0:06:59This is your question.
0:06:59 > 0:07:05What is the weight of the heaviest recorded hailstone in the UK?
0:07:05 > 0:07:10What is the weight of the heaviest recorded hailstone in the UK?
0:07:10 > 0:07:14- Five, four, three... - I'll have to hurry you, teams.
0:07:14 > 0:07:18Get your answer written down. What do you reckon? Nine kilograms.
0:07:18 > 0:07:19That's quite big.
0:07:19 > 0:07:25Reds? 1.75 kilograms. Pretty accurate there.
0:07:25 > 0:07:28OK, the real answer is...
0:07:28 > 0:07:30142...
0:07:30 > 0:07:32grams,
0:07:32 > 0:07:37which means, although they're miles out, the Red Team get it.
0:07:37 > 0:07:40They are the nearest with 1.75 kilograms.
0:07:40 > 0:07:41APPLAUSE
0:07:41 > 0:07:45That is about the weight of a cricket ball.
0:07:45 > 0:07:48It fell at Horsham, West Sussex, on 5th September 1958.
0:07:48 > 0:07:51That means the Reds have seized control.
0:07:51 > 0:07:53They have the first light lit green.
0:07:53 > 0:07:56You get the first true or false science fact.
0:07:56 > 0:08:01The smallest bone in the human body is in the foot.
0:08:01 > 0:08:03Is that true or false?
0:08:03 > 0:08:07The smallest bone in the human body is in the foot? Is it true or false?
0:08:07 > 0:08:08It's false.
0:08:08 > 0:08:11You think it's false? That's what you think?
0:08:11 > 0:08:13The Red Team thinks it's false.
0:08:13 > 0:08:16How you're going to answer the question I've delivered to you
0:08:16 > 0:08:18is by saying "false"?
0:08:18 > 0:08:21OK, we should find out what the real answer is, shouldn't we?
0:08:21 > 0:08:23Oliver...
0:08:23 > 0:08:26The smallest bone in the human body is in the foot.
0:08:26 > 0:08:28Is that true or false?
0:08:28 > 0:08:29DEEP HORN
0:08:29 > 0:08:31It's false, correct. Well done.
0:08:34 > 0:08:37The smallest bone in your body is in your ear.
0:08:37 > 0:08:39There are three bones in your ears that help you hear,
0:08:39 > 0:08:42and the smallest one of them is 3.3 millimetres across,
0:08:42 > 0:08:45and that's smaller than even your little toe.
0:08:45 > 0:08:47Yellows, things are looking tricky.
0:08:47 > 0:08:49Don't worry. This can change very quickly.
0:08:49 > 0:08:51This is your science fact.
0:08:51 > 0:08:54The hairs of a polar bear are actually brown.
0:08:54 > 0:08:56Is that true or is that false?
0:08:56 > 0:08:59The hairs of a polar bear are actually brown.
0:08:59 > 0:09:02Is that true or false?
0:09:02 > 0:09:03- False.- You're saying false?
0:09:03 > 0:09:05We should probably find out
0:09:05 > 0:09:07by asking Oliver what the real answer is.
0:09:10 > 0:09:13Oliver, is it true or false?
0:09:13 > 0:09:14DEEP HORN
0:09:14 > 0:09:16It is false, well done!
0:09:16 > 0:09:18Phew!
0:09:18 > 0:09:20Well done. You're still in the game.
0:09:20 > 0:09:23Believe it or not, polar bears' hairs
0:09:23 > 0:09:25actually have no colour at all.
0:09:25 > 0:09:27They're colourless and hollow.
0:09:27 > 0:09:29This makes the hairs look white,
0:09:29 > 0:09:30even though they're not,
0:09:30 > 0:09:33because of how light bounces around within them.
0:09:33 > 0:09:36Reds, you have two lights lit. Get this one right and you win.
0:09:36 > 0:09:40Get it wrong, they stand a chance of winning next time round.
0:09:40 > 0:09:46The Earth is hit by about 1,000 kilograms of meteors each day.
0:09:46 > 0:09:49Is that true or false?
0:09:49 > 0:09:51True.
0:09:51 > 0:09:54You think it's true. Oliver, is it true or false?
0:09:54 > 0:09:55DEEP HORN
0:09:55 > 0:10:00It's false, and that means the light is lit for the Yellows.
0:10:00 > 0:10:01They're on two.
0:10:01 > 0:10:06OK, Yellows, I hardly need to point out where we are right now.
0:10:06 > 0:10:08If you answer this correctly, you win.
0:10:08 > 0:10:11If you're wrong, the Reds win.
0:10:11 > 0:10:14OK, this is your science fact.
0:10:14 > 0:10:18Silver is the best metal at conducting electricity.
0:10:18 > 0:10:21Is that true or false?
0:10:21 > 0:10:24Having a think because it all hangs on this.
0:10:24 > 0:10:26Let's see what you think, audience.
0:10:26 > 0:10:29- Is it true or false? - KLAXON
0:10:32 > 0:10:35Again, the audience just divided down the middle.
0:10:35 > 0:10:39They're no help to you, Yellows. You can't tell much from that.
0:10:39 > 0:10:42- Who's guessing?- I actually have no clue.- No clue, OK.
0:10:42 > 0:10:46- It looks like hard metal. - Yeah, it does. It's a hard metal.
0:10:46 > 0:10:49Metals are quite different, aren't they?
0:10:49 > 0:10:50Some are really soft.
0:10:50 > 0:10:52Lead's very soft.
0:10:52 > 0:10:55Some are hard. Some are light. Could that affect it?
0:10:55 > 0:10:57- Maybe.- You're thinking on the right lines.
0:10:57 > 0:11:00Something about the metal makes it good at conducting.
0:11:00 > 0:11:03OK, audience. Thank you very much.
0:11:03 > 0:11:06Silver is the best metal at conducting electricity.
0:11:06 > 0:11:08- True or false?- True. - You think it's true?
0:11:08 > 0:11:13Obviously, if it's true, you win. If it's false, they win.
0:11:13 > 0:11:15Oliver, is it true or false?
0:11:15 > 0:11:16WHIRRING SIRENS
0:11:16 > 0:11:20SPEECH DROWNED BY CHEERING
0:11:22 > 0:11:24It's also the best conductor of heat,
0:11:24 > 0:11:28but electrical wires are usually made of copper because it's cheaper.
0:11:28 > 0:11:30Congratulations. Three lights lit first
0:11:30 > 0:11:34and it went right down to the wire. That was a hard-fought competition.
0:11:34 > 0:11:36That means it's 1-0 to the Yellows.
0:11:52 > 0:11:55Now, they do say you're supposed to learn from your mistakes.
0:11:55 > 0:11:59I didn't because exactly the same thing happened when I tried to make
0:11:59 > 0:12:01a time machine to bring my old science teacher
0:12:01 > 0:12:05back from school to the Blast Lab as happened the first time I did it
0:12:05 > 0:12:06with Kyle, my pet gerbil.
0:12:06 > 0:12:10My science teacher came back as a ten-year-old girl and my gerbil
0:12:10 > 0:12:14came back as a ten-year-old gerbil, which is far too old for gerbils.
0:12:14 > 0:12:16I'm talking, of course, about Mini Miss!
0:12:27 > 0:12:30- You made a right mess of it, Richard. - It could have been worse.
0:12:30 > 0:12:33You could have come back as a ten-year-old gerbil.
0:12:33 > 0:12:37Stop being ridiculous, Richard, or I will have to send you out of the lab.
0:12:37 > 0:12:40- Sorry, Miss.- Now, you are going to be helping me
0:12:40 > 0:12:45in an experiment with water tension with a game I like to call...
0:12:47 > 0:12:51Tense water? I didn't realise that water could get stressed.
0:12:51 > 0:12:54It can't.
0:12:54 > 0:12:59But I will get stressed if you keep testing my patience!
0:12:59 > 0:13:02- Sorry, Miss.- There is a large water-filled cylinder
0:13:02 > 0:13:06over Ninja Nan's head and each team has to take it in turns
0:13:06 > 0:13:09to poke holes into the clingfilm.
0:13:09 > 0:13:12Ah, now hold on, Miss. From what I remember from school,
0:13:12 > 0:13:18which isn't much, this is about water tension because it'll be
0:13:18 > 0:13:20water tension that'll keep the water in
0:13:20 > 0:13:22when they put holes in the cylinder.
0:13:22 > 0:13:25But then eventually, if the holes get too big or in the wrong place,
0:13:25 > 0:13:29the water will come out and it'll fill this funnel
0:13:29 > 0:13:32and I'm guessing that the team who causes it to spill over
0:13:32 > 0:13:36and land on Ninja Nan will lose and there'll be one heck of a scene.
0:13:36 > 0:13:39- Very good, Richard. - Thank you very much, Miss.
0:13:39 > 0:13:43I'm quite tired after all that thinking, so, teams, you can have
0:13:43 > 0:13:46time to talk with Mini Miss about what you're going to do.
0:13:46 > 0:13:48You have access to her brain, which is enormous.
0:13:48 > 0:13:52I'll leave you to do that. OK, have a chat, have a think.
0:13:55 > 0:14:00So this really is about water tension. Water tension only exists
0:14:00 > 0:14:04because water molecules, the little tiny bits that make up water,
0:14:04 > 0:14:06really like each other and they cling together.
0:14:06 > 0:14:09You can see it in action here. This glass, nearly full of water.
0:14:09 > 0:14:12I can keep pouring more and more water in
0:14:12 > 0:14:15and more and more water until, if you look closely,
0:14:15 > 0:14:19the water is actually sticking up beyond the top of the glass.
0:14:19 > 0:14:22That's because the water molecules are sticking together.
0:14:22 > 0:14:26If I keep pouring, eventually the water tension is enough
0:14:26 > 0:14:27and the water spills out.
0:14:27 > 0:14:31So it'll be water tension when they put the holes in the clingfilm here
0:14:31 > 0:14:33that holds it in.
0:14:33 > 0:14:37Of course, there's another factor in this - air.
0:14:37 > 0:14:41For water to come out, air has got to get in to replace it.
0:14:41 > 0:14:43So once the holes reach a point
0:14:43 > 0:14:46when they're big enough for air to get in as well,
0:14:46 > 0:14:49more water will come out. This will fill up.
0:14:49 > 0:14:52Some water will always come out, but the team that causes it to spill
0:14:52 > 0:14:58over and land on Ninja Nan's head, well, they can answer to Ninja Nan.
0:14:58 > 0:15:00- Teams, do you understand?- Yes.
0:15:00 > 0:15:03OK, Yellows, you're in the lead, 1-0, so you get to decide.
0:15:03 > 0:15:05Do you want to go first or second?
0:15:05 > 0:15:10- First.- First, OK. You're about to run the risk of soaking Ninja Nan.
0:15:10 > 0:15:15I don't think that's something any of us want right now, so good luck.
0:15:15 > 0:15:18No pressure. Step forward and make a hole if you like.
0:15:18 > 0:15:19Teams, away we go.
0:15:21 > 0:15:23Here we go.
0:15:23 > 0:15:26Ooh, a little bit of water will come out. Oh, that's it.
0:15:26 > 0:15:30Just a tiny few drops. OK, Reds, here we go.
0:15:30 > 0:15:33OK, first off. Ooh, ooh...
0:15:33 > 0:15:36That's it, it's stopped. Yellows, in you come.
0:15:36 > 0:15:39What's holding the water in is water tension.
0:15:39 > 0:15:43The water molecules like being next to each other. They cling on.
0:15:45 > 0:15:48We've added some dye into the bottom of the funnel
0:15:48 > 0:15:51so we can see the level of water as it rises up,
0:15:51 > 0:15:56over the head of the most lethal weapon known to lab-rat-kind.
0:16:02 > 0:16:06Ooooh. A fair bit of water able to come out,
0:16:06 > 0:16:08but that's OK. We've got a long way to go.
0:16:08 > 0:16:13We've got to fill this funnel before we're really in trouble. OK.
0:16:13 > 0:16:15Look! Oh, bold play.
0:16:15 > 0:16:19He's going straight for the middle. Look at that. A brave young man.
0:16:19 > 0:16:23Oooh! The Yellows, really... Oh, that's good play from the Yellows.
0:16:23 > 0:16:27Getting some water in there makes it harder for the Reds next time.
0:16:27 > 0:16:30You know when it's going to drip because you see the bubbles of air
0:16:30 > 0:16:32go up first.
0:16:32 > 0:16:36Ooh! Well played, the Reds! That's sending some water in.
0:16:36 > 0:16:39The Yellows have to answer back. Whatever you put in the funnel,
0:16:39 > 0:16:41they've got to put more on top of it.
0:16:41 > 0:16:43Ooh!
0:16:45 > 0:16:50It's got to be done, it's got to be done. No pressure, Ruth.
0:16:53 > 0:16:54AUDIENCE: Oh!
0:16:54 > 0:16:57She's not comfortable with that at all.
0:16:57 > 0:17:01- It was an accident. - Oh, she's not comfortable with that.
0:17:01 > 0:17:04Oh, Reds. Oh, Reds.
0:17:06 > 0:17:08Oh, Reds.
0:17:08 > 0:17:10Oh, Reds!
0:17:10 > 0:17:13It may yet stop. It may stop.
0:17:15 > 0:17:18We can declare the Yellows as the winners.
0:17:18 > 0:17:22That was incredibly tense. Come forward, teams, please.
0:17:22 > 0:17:26Both sides up here because that was.... She's OK.
0:17:26 > 0:17:29She's actually still meditating. We're OK.
0:17:29 > 0:17:32- CRACK! - Uh! That was quite incredibly tense,
0:17:32 > 0:17:35but I can declare that the point goes to the Yellows.
0:17:35 > 0:17:38It is now 2-0 to the Yellows.
0:17:38 > 0:17:40CHEERING
0:17:40 > 0:17:44That was it. It just went.
0:17:44 > 0:17:47Now, I admit I may have mucked up my own time-travelling experiments
0:17:47 > 0:17:51with Mini Miss, so when I heard of a scientist who said he could
0:17:51 > 0:17:53do time travel properly, I had to investigate.
0:17:55 > 0:17:59Great Auntie Matilda's chicken drumsticks! What is going on here?!
0:17:59 > 0:18:01Hold it right there. Who are you?
0:18:01 > 0:18:04HIGH-PITCHED, GARBLED SPEECH:
0:18:04 > 0:18:05Who?
0:18:07 > 0:18:10Doctor who?
0:18:11 > 0:18:14That's not a real name. It doesn't have any vowels.
0:18:14 > 0:18:15You're not a real doctor.
0:18:16 > 0:18:18No. You're just a lab rat in my old coat.
0:18:18 > 0:18:20And that's not a real alien robot you're fighting.
0:18:20 > 0:18:24You're just a lab rat in a cardboard box covered in tin foil.
0:18:24 > 0:18:27Yes, you are. I can see your foot.
0:18:29 > 0:18:32Right, I'm going to give you one chance to prove
0:18:32 > 0:18:34that you are a real "alien mysterious time lord".
0:18:34 > 0:18:37I'm going to send you on a mission. You'd better take that
0:18:37 > 0:18:40or him with you cos you might need a sidekick.
0:18:47 > 0:18:49And the mission I've chosen
0:18:49 > 0:18:51is to break the world javelin record,
0:18:51 > 0:18:54which currently stands at 98.48 metres,
0:18:54 > 0:18:57held by a man with a woman's name, Jan.
0:18:57 > 0:19:04Using my trusty Cardis, they've gone all the way back in time to...
0:19:04 > 0:19:07Well, if my knowledge of Roman battleground fashion is accurate,
0:19:07 > 0:19:10I'd say that our time lord and his hapless assistant have landed
0:19:10 > 0:19:16around 50 BC, which, judging by the weather, must mean "a bit cold".
0:19:16 > 0:19:19But how are they going to beat the javelin world record
0:19:19 > 0:19:21with a bunch of blokes dressed like a cross
0:19:21 > 0:19:23between a tin of beans and Superman?
0:19:23 > 0:19:26I don't know. Hang on a minute.
0:19:26 > 0:19:30That's a ballista. Ah, now I see what they're doing.
0:19:30 > 0:19:35The Roman ballista was one of the most formidable weapons in history.
0:19:35 > 0:19:38In fact, Julius Caesar used them in his conquest of Gaul
0:19:38 > 0:19:42around 55 BC to great effect.
0:19:42 > 0:19:46Capable of firing bolts or stones, the largest of them could hurl
0:19:46 > 0:19:51objects weighing in excess of 100kg, and here's how it worked.
0:19:55 > 0:19:58A ballista is like a crossbow but bigger.
0:19:58 > 0:20:01When the handle on the ballista is turned, the rope holding
0:20:01 > 0:20:05the arrow in place is pulled back and made tighter.
0:20:05 > 0:20:07When the rope is as tight as possible,
0:20:07 > 0:20:09it has a lot of potential energy.
0:20:09 > 0:20:13On releasing the rope, this potential energy is transferred
0:20:13 > 0:20:17into kinetic or movement energy, launching the arrow into the air.
0:20:17 > 0:20:21But will the energy stored within these strings be capable of breaking
0:20:21 > 0:20:25that javelin world record of 98.48 metres?
0:20:27 > 0:20:29OK, hold the experiment right there,
0:20:29 > 0:20:32because there is a point up for grabs. I know the score, 2-0 -
0:20:32 > 0:20:34it won't make any difference overall,
0:20:34 > 0:20:37but I think just for the honour of the point
0:20:37 > 0:20:39we should play on and it hinges on this question.
0:20:39 > 0:20:43Will they break the world record? What do you think?
0:20:43 > 0:20:45- Will it work, Yellows?- Yes.
0:20:45 > 0:20:48- No.- Good! I like it when we have a difference
0:20:48 > 0:20:51of opinion. So you think they won't. You think they will.
0:20:51 > 0:20:53One point's up for grabs. Let's find out.
0:20:53 > 0:20:55Carry on with the experiment.
0:20:59 > 0:21:01Tasked with beating a world record,
0:21:01 > 0:21:04the wannabe time lord and his hapless assistant have gone
0:21:04 > 0:21:09back in time to around 55 BC, the height of the Roman Empire,
0:21:09 > 0:21:16where they hope to beat the world record javelin throw of 98.48 metres
0:21:16 > 0:21:18with this.
0:21:18 > 0:21:23It's a Roman ballista, armed with a wooden bolt.
0:21:23 > 0:21:26Our legionnaires are ready, so here we go.
0:21:29 > 0:21:32Tres, duo, unus.
0:21:38 > 0:21:42Well, that's incredible and just look at it in slow motion.
0:21:44 > 0:21:47The force of the ballista has shot the bolt well over
0:21:47 > 0:21:51the 100 metres mark, but how far?
0:21:51 > 0:21:52The tape measure says 59 metres.
0:21:52 > 0:21:56That shattered the javelin world record with a total distance
0:21:56 > 0:22:00of 159 metres. Result!
0:22:00 > 0:22:04And that brings the score to 3-0 to the Yellows.
0:22:04 > 0:22:06Right, now it is time for...
0:22:10 > 0:22:12Which, of course, involves my Snot Bots over here.
0:22:12 > 0:22:14I'm so proud of these creations.
0:22:14 > 0:22:16One day they will be replacing the lab rats.
0:22:16 > 0:22:20So clever that they have started taking on human characteristics,
0:22:20 > 0:22:23like catching terrible colds.
0:22:23 > 0:22:26I'm sorry about that. It really is disgusting.
0:22:26 > 0:22:30OK, hidden in that gunge are prize discs.
0:22:30 > 0:22:32Written on them are the names of prizes.
0:22:32 > 0:22:34Today we've a practical joke set,
0:22:34 > 0:22:37a radio-controlled spider and an electromagnetic kit.
0:22:37 > 0:22:38The team with the most discs
0:22:38 > 0:22:41slotted into the open mouth of their Snot Bot
0:22:41 > 0:22:44at the end of the game will win and take the prizes home.
0:22:44 > 0:22:46Remember, the Yellows have the lead.
0:22:46 > 0:22:50That's bought you a five-second head start. You have some time to find
0:22:50 > 0:22:54as many prize discs as you can, and that some time starts...now!
0:22:54 > 0:22:57Some time is ticking and the Yellows
0:22:57 > 0:23:01are wasting none of it getting quite literally stuck in.
0:23:01 > 0:23:03- SIREN - There's the second siren.
0:23:03 > 0:23:07The Reds are off. But it looks like it's going to be the Yellows
0:23:07 > 0:23:12who are first off the mark. There's Ruth ready with a disc as well
0:23:12 > 0:23:14and in it goes. One for the Reds.
0:23:14 > 0:23:19And another for the Yellows. The prize discs are flying in today.
0:23:19 > 0:23:22Yet another disc has been found by the Yellows.
0:23:22 > 0:23:23There's no stopping them.
0:23:23 > 0:23:26And James has been passed another yellow disc
0:23:26 > 0:23:29and the Reds have one as well.
0:23:29 > 0:23:34It really is anyone's game...probably.
0:23:34 > 0:23:36There's another one found by the Yellows.
0:23:36 > 0:23:39The prize discs must be getting a little thin on the ground now
0:23:39 > 0:23:43with both teams putting in flawless displays of disc discovery.
0:23:50 > 0:23:55Well, some time is up, teams. Whoa, that's a lot of gunge on you guys.
0:23:55 > 0:23:58We must now find out how you teams have done.
0:23:58 > 0:24:01Lab rat, how many have we got for the Reds? Let's have a look.
0:24:01 > 0:24:05How many have we got, lab rat? Six prize discs for the Reds. Well done!
0:24:05 > 0:24:07How many for the Yellows?
0:24:07 > 0:24:10Ten!
0:24:10 > 0:24:12CHEERING, APPLAUSE
0:24:12 > 0:24:15That's amazing! That is a win for the Yellows.
0:24:15 > 0:24:17Let's have a look at what you've got.
0:24:17 > 0:24:20You've got a model speedboat.
0:24:21 > 0:24:25A radio-controlled spider for each of you.
0:24:25 > 0:24:28A voice warper.
0:24:28 > 0:24:31A pogo stick.
0:24:31 > 0:24:32A practical joke set.
0:24:34 > 0:24:36A puzzle cube.
0:24:38 > 0:24:39A soap factory.
0:24:39 > 0:24:44You'll need that after this for certain! An electromagnetic kit.
0:24:46 > 0:24:49A skeleton model.
0:24:49 > 0:24:51A metal detector.
0:24:53 > 0:24:56Wow, that's staggering! Congratulations, Yellows.
0:24:56 > 0:25:00Now, a slightly trickier duty to perform because we must find out
0:25:00 > 0:25:02what the Reds would have been taking home with them.
0:25:02 > 0:25:04An electromagnetic kit.
0:25:04 > 0:25:08Very nice. A model speed boat.
0:25:08 > 0:25:10- AUDIENCE: Aw!- A soap factory.
0:25:10 > 0:25:14Yes, handy right now as well. A practical joke set.
0:25:16 > 0:25:20A lunar eclipse bedroom light. Very nice.
0:25:20 > 0:25:23- And a personal room moon. - AUDIENCE: Aw!
0:25:23 > 0:25:26I know, but, Reds, it's OK, cos here's the thing.
0:25:26 > 0:25:29You're not going to take them home with you. Instead,
0:25:29 > 0:25:34you're going to blow them up because it's time for Bidet Goes Bang!
0:25:42 > 0:25:46Yellows, you have emptied my prize cupboard. Well done, well played.
0:25:46 > 0:25:48All that lot going home with you.
0:25:48 > 0:25:53Reds, you did really well and I'm really very sorry,
0:25:53 > 0:25:56but it's OK because, instead of taking them home,
0:25:56 > 0:26:00what you're going to do is follow me along the Walk Of Shame.
0:26:02 > 0:26:05AUDIENCE: Aw!
0:26:05 > 0:26:07I know. It's... It's... Aw.
0:26:15 > 0:26:18Reds, you were great sports,
0:26:18 > 0:26:20and you were great fun to have here in the Blast Lab.
0:26:20 > 0:26:23Thank you for playing and I'm really sorry,
0:26:23 > 0:26:24but you know what you must do.
0:26:24 > 0:26:26Lift the plunger.
0:26:26 > 0:26:29It's time to say goodbye to those prizes. Lift it up.
0:26:31 > 0:26:34Here we go, audience, we'll count them down from five.
0:26:34 > 0:26:39ALL: Five, four, three, two, one.
0:26:43 > 0:26:45CHEERING, APPLAUSE
0:26:47 > 0:26:50Reds, well done. Well done, girls. So, that is just about it.
0:26:50 > 0:26:54We've investigated how water tension can keep you dry...ish
0:26:54 > 0:26:58and how spring tension can make a lab rat wet.
0:26:58 > 0:27:00I'll see you again next time.
0:27:25 > 0:27:27Subtitles by Red Bee Media Ltd
0:27:27 > 0:27:29E-mail subtitling@bbc.co.uk