0:00:10 > 0:00:14For 50 years, Horizon has provided us with an insight
0:00:14 > 0:00:17into the very best of scientific discovery
0:00:17 > 0:00:20and technological innovation from around the world.
0:00:22 > 0:00:25Our films have featured some of the biggest names in science
0:00:25 > 0:00:30and brought you the latest advances in everything from medicine
0:00:30 > 0:00:35to computer technology - space science to biology.
0:00:35 > 0:00:39As the 21st century marches on, the world faces a whole new set
0:00:39 > 0:00:41of scientific challenges.
0:00:41 > 0:00:44To celebrate Horizon's 50th anniversary,
0:00:44 > 0:00:47we're inviting YOU to get involved.
0:00:47 > 0:00:51The question is, if you had £10 million
0:00:51 > 0:00:56to make one change to the world, what would that be?
0:00:57 > 0:01:02This week, a Prize Fund is launched to help solve one key problem
0:01:02 > 0:01:05facing our society today.
0:01:05 > 0:01:08And we want you to decide what that is.
0:01:09 > 0:01:13We've put together a team to help you choose.
0:01:13 > 0:01:17From antibiotic resistance, to carbon emissions from planes...
0:01:19 > 0:01:21I wasn't expecting that!
0:01:21 > 0:01:25..from our thirst for fresh water,
0:01:25 > 0:01:28to our hunger for food to feed the world.
0:01:28 > 0:01:31They do provide a satisfying crunch.
0:01:31 > 0:01:34And from the burden posed by dementia care,
0:01:34 > 0:01:37to the difficulty of life in a wheelchair.
0:01:37 > 0:01:40Everything I use is in the lower cupboards.
0:01:40 > 0:01:42Don't like wasabi! All the stuff I don't like's at the top!
0:01:42 > 0:01:48Which of these is most in need of ten million pounds?
0:01:48 > 0:01:50It's your choice.
0:01:50 > 0:01:53And that's not all, because if you or your team
0:01:53 > 0:01:56are sitting on an idea which could solve the problem,
0:01:56 > 0:01:59that £10 million could be yours.
0:02:09 > 0:02:12This is the Royal Observatory, Greenwich -
0:02:12 > 0:02:15a place of huge importance in the history of science.
0:02:15 > 0:02:18And it's where the story of today's Prize Challenge started
0:02:18 > 0:02:20300 years ago.
0:02:22 > 0:02:261714 saw the launch of perhaps the most famous
0:02:26 > 0:02:29science prize in history - one that put Greenwich,
0:02:29 > 0:02:32and British science, on the map for ever.
0:02:34 > 0:02:35Just like the new prize,
0:02:35 > 0:02:40it was prompted by the need for science to solve a grave problem -
0:02:40 > 0:02:44one that faced every sea-faring nation on earth.
0:02:46 > 0:02:50300 years ago, naval navigation was perilous,
0:02:50 > 0:02:54because when they were out at sea, far from any landmarks,
0:02:54 > 0:02:58it was extremely difficult for sailors to know precisely where they were.
0:03:00 > 0:03:03That problem caused one of the most tragic accidents
0:03:03 > 0:03:05in British naval history.
0:03:05 > 0:03:09On one terrible night in 1707, four ships sank
0:03:09 > 0:03:14near the Isles of Scilly, with the loss of over 1,400 lives.
0:03:14 > 0:03:17The sailors died because they couldn't work out
0:03:17 > 0:03:19exactly where they were.
0:03:19 > 0:03:25The hardest task of all for any navigator was to work out their longitude.
0:03:27 > 0:03:30To calculate their position around the globe, in theory
0:03:30 > 0:03:32all they needed to know was the time difference
0:03:32 > 0:03:35between where they were and London -
0:03:35 > 0:03:40every four minutes would translate into one degree of longitude.
0:03:40 > 0:03:42But in practice,
0:03:42 > 0:03:46it was virtually impossible to keep track of the time back in London.
0:03:46 > 0:03:49The clocks of the period were pendulum clocks,
0:03:49 > 0:03:54and as soon the ship started to pitch and roll in the waves,
0:03:54 > 0:03:58you can see it would've been very difficult to keep good time.
0:03:59 > 0:04:02But ocean travel was booming in the 18th century -
0:04:02 > 0:04:05something had to be done to make it safe.
0:04:05 > 0:04:07Parliament appointed a committee of scientists -
0:04:07 > 0:04:11the Board of Longitude - to solve the problem.
0:04:11 > 0:04:14And in desperation they appealed to the nation,
0:04:14 > 0:04:18offering a reward of £20,000 for the best solution.
0:04:20 > 0:04:23That cash prize, worth several million today,
0:04:23 > 0:04:27became the catalyst for one of the most world-changing innovations
0:04:27 > 0:04:29in the history of technology.
0:04:31 > 0:04:33Now, a new Longitude Committee has been formed,
0:04:33 > 0:04:39to oversee a prize offered by Nesta, the UK's innovation foundation.
0:04:39 > 0:04:43But the prize can only be offered for one of the six problems
0:04:43 > 0:04:47on tonight's short list. And that's where you come in.
0:04:47 > 0:04:49In this programme, we'll be revealing
0:04:49 > 0:04:53the details of those six nominated challenges for the first time
0:04:53 > 0:04:56and then asking you to vote
0:04:56 > 0:05:01to decide which of the challenges is worth the £10 million.
0:05:01 > 0:05:04You'll be able to vote right after this programme,
0:05:04 > 0:05:10either by text, or by visiting bbc.co.uk/horizon.
0:05:10 > 0:05:13There you'll find links to in-depth guides to the six choices.
0:05:15 > 0:05:17Your decision will launch a five-year search
0:05:17 > 0:05:21for prize-winning solutions that could change the world.
0:05:24 > 0:05:28Let's look at the first problem on our list.
0:05:30 > 0:05:35Bacterial resistance to antibiotics has been a growing problem
0:05:35 > 0:05:39for decades, and now poses a very real threat to our health.
0:05:39 > 0:05:41It presents a nightmare vision of the future,
0:05:41 > 0:05:45in which the health of practically everybody alive on the planet
0:05:45 > 0:05:49is at risk in a way that it hasn't been for almost a century.
0:05:50 > 0:05:54Since Alexander Fleming discovered penicillin over 80 years ago,
0:05:54 > 0:05:57it's been estimated that antibiotics have saved
0:05:57 > 0:06:00more than 80 million lives.
0:06:00 > 0:06:04But now, there are some bacteria that we're defenceless against.
0:06:04 > 0:06:08Every year in the UK, 5,000 people die
0:06:08 > 0:06:12because antibiotics can't kill the bacteria they're infected with.
0:06:15 > 0:06:18Looking at the problem of antibiotic-resistant super-bugs,
0:06:18 > 0:06:20here's Liz Bonnin.
0:06:25 > 0:06:30Antibiotics have only been widely available for 70 years or so
0:06:30 > 0:06:35but the effect they've had on our lives is nothing short of extraordinary.
0:06:35 > 0:06:38In that time, life expectancy has increased by 20 years,
0:06:38 > 0:06:42thanks in large part to the dramatic reduction in deaths
0:06:42 > 0:06:45from all sorts of infections and infectious diseases.
0:06:46 > 0:06:51Without antibiotics, modern medicine as we know it wouldn't exist.
0:06:51 > 0:06:53Routine operations would be life-threatening
0:06:53 > 0:06:58and everything from hip replacements to chemotherapy and organ transplants
0:06:58 > 0:07:00would simply be impossible.
0:07:00 > 0:07:03But it seems the heyday is over.
0:07:03 > 0:07:07Infectious bacteria are becoming increasingly resistant
0:07:07 > 0:07:09to the antibiotics we rely on for protection.
0:07:11 > 0:07:15We urgently need to preserve this cornerstone of modern medicine
0:07:15 > 0:07:20and to do that we need to understand why resistance is on the increase.
0:07:23 > 0:07:25I've come to Birmingham to meet Professor Laura Piddock -
0:07:25 > 0:07:28a specialist in antibiotic resistance.
0:07:29 > 0:07:32So, Laura, how can bacteria become resistant to the antibiotics
0:07:32 > 0:07:36that have been so effective against them for so long?
0:07:36 > 0:07:40OK, so it's best demonstrated if we look at this plate here.
0:07:40 > 0:07:43So you can see the bacteria growing on the top of the agar,
0:07:43 > 0:07:46and there's a disc in the middle that's got antibiotic in it,
0:07:46 > 0:07:49and the antibiotic is coming out into the agar
0:07:49 > 0:07:53and there's this clear zone that's killing all those bacteria.
0:07:54 > 0:07:56- OK, so that's how antibiotics work? - Yeah.
0:07:56 > 0:07:59But if you look very closely, you can see there's little dots,
0:07:59 > 0:08:02little colonies, that have grown up overnight
0:08:02 > 0:08:04so they are antibiotic resistant.
0:08:04 > 0:08:08And the way that's happened is they have a mutation in one gene
0:08:08 > 0:08:11that now allows them to resist that antibiotic.
0:08:11 > 0:08:13And if we take one of those resistant colonies,
0:08:13 > 0:08:15and then do them on this plate here...
0:08:15 > 0:08:18One dot of that, grown out on this agar?
0:08:18 > 0:08:22Yeah. And you can see that it's grown right up to the disc
0:08:22 > 0:08:25with the antibiotic, there's no zone of inhibition.
0:08:25 > 0:08:29And that's it, a completely resistant strain of bacteria to that drug.
0:08:29 > 0:08:33And that drug becomes obsolete, that's the end of its working life.
0:08:33 > 0:08:38- Yes.- So what have we done to contribute to this resistance?
0:08:38 > 0:08:40Well, we're awash with antibiotics.
0:08:40 > 0:08:42We need to stop using them as much as we do,
0:08:42 > 0:08:46not just in human medicine, we need to stop using them in animals,
0:08:46 > 0:08:49as much as they are, we need to stop using them in the home.
0:08:49 > 0:08:52We want to make sure patients get the drugs when they need them,
0:08:52 > 0:08:54but what we don't want to do is have people using them
0:08:54 > 0:08:57when they're just absolutely unnecessary.
0:08:58 > 0:09:02It's clear we need to halt our excessive use of antibiotics.
0:09:04 > 0:09:0850 million courses of antibiotics are prescribed in UK hospitals
0:09:08 > 0:09:11and GP surgeries every year.
0:09:11 > 0:09:15And the trouble is, up to half of those prescribed
0:09:15 > 0:09:17are probably unnecessary.
0:09:20 > 0:09:22If we could develop a quick and easy way to tell
0:09:22 > 0:09:26the difference between viral and bacterial infections
0:09:26 > 0:09:29then the use of antibiotics could be dramatically reduced.
0:09:29 > 0:09:31You can see we're on a busy ward here.
0:09:31 > 0:09:33We have sick patients coming in all the time.
0:09:33 > 0:09:36And it's often quite difficult to work out clinically
0:09:36 > 0:09:38whether they have a serious infection or not.
0:09:38 > 0:09:39That's the real challenge.
0:09:39 > 0:09:43We often give antibiotics just in case there's serious infection.
0:09:43 > 0:09:46What we really need is good strategies to be able
0:09:46 > 0:09:49to deliver antibiotics to the patients who really need them
0:09:49 > 0:09:51with confidence they have a bacterial infection
0:09:51 > 0:09:54and not some other condition or a viral infection.
0:09:54 > 0:09:57So how do you go about discerning between a viral infection
0:09:57 > 0:09:58and a bacterial one?
0:09:58 > 0:10:00It can be very difficult
0:10:00 > 0:10:02but we are helped with various blood tests
0:10:02 > 0:10:05and there's a relatively new blood test, a biomarker
0:10:05 > 0:10:09called procalcitonin, and we can use that in conjunction with
0:10:09 > 0:10:11our clinical assessment of the patient
0:10:11 > 0:10:15to try and help us establish if the patient has a bacterial infection.
0:10:15 > 0:10:20Doctor Dryden is trialling a new technique to measure procalcitonin -
0:10:20 > 0:10:23a molecule found in the blood which rises in concentration
0:10:23 > 0:10:27when you have a bacterial infection but not if you have a viral one.
0:10:27 > 0:10:31I'm not on the ward for long before a test is necessary.
0:10:36 > 0:10:38We've just seen a very sick lady.
0:10:38 > 0:10:41It's difficult to make a clear diagnosis in this patient.
0:10:41 > 0:10:44She could well have pneumonia and septicaemia
0:10:44 > 0:10:47but equally it may not be due to a bacterial infection.
0:10:48 > 0:10:52By using a biomarker like procalcitonin that can help us
0:10:52 > 0:10:56make a decision whether this patient needs antibiotics or not.
0:11:00 > 0:11:03After just 90 minutes, Doctor Dryden gets the results.
0:11:04 > 0:11:07We have just done the test on the patient we saw
0:11:07 > 0:11:10and the procalcitonin level is below the cut-off.
0:11:10 > 0:11:13So I presume you are not going to administer antibiotics.
0:11:13 > 0:11:16We held off the antibiotics on the ward round this morning
0:11:16 > 0:11:18and we'll continue to hold off.
0:11:18 > 0:11:21We will continue to monitor her and keep a close eye on her
0:11:21 > 0:11:25and if her condition changes, we may change that decision.
0:11:25 > 0:11:27But at the moment, she doesn't need antibiotics.
0:11:27 > 0:11:31Because of this test, the hospital has been able to have
0:11:31 > 0:11:35the antibiotics it prescribes when diagnoses are unclear.
0:11:35 > 0:11:38But the equipment remains bulky and expensive.
0:11:38 > 0:11:41And as most antibiotics are prescribed by GPs,
0:11:41 > 0:11:43the test is nowhere near fast enough.
0:11:43 > 0:11:46Speed is absolutely of the essence in the community.
0:11:46 > 0:11:49If you think about how short a consultation is with the GP,
0:11:49 > 0:11:53a GP sees a patient for 10 minutes, that has to be done within that 10 minutes.
0:11:53 > 0:11:55So, it's an exciting time for the research
0:11:55 > 0:11:59for the technology of these types of tests, but how urgent is this?
0:11:59 > 0:12:03I think it's really important to develop this as soon as possible.
0:12:03 > 0:12:05We know antibiotics in the past have saved more lives
0:12:05 > 0:12:07than any other drugs.
0:12:07 > 0:12:10If we don't preserve our antibiotics, or find new ones,
0:12:10 > 0:12:12the future of medicine is really in doubt.
0:12:14 > 0:12:19Our massive overuse of antibiotics across the globe is crippling
0:12:19 > 0:12:22one of the most effective weapons we have against infection.
0:12:23 > 0:12:25We urgently need a solution
0:12:25 > 0:12:29because this will affect all our lives in the future.
0:12:30 > 0:12:33If this subject is picked for the Longitude Prize,
0:12:33 > 0:12:35potential winners will need to develop
0:12:35 > 0:12:38a cheap, rapid test for bacterial infections
0:12:38 > 0:12:42that can be used easily by doctors and nurses all over the world.
0:12:45 > 0:12:49Getting a rapid diagnostic so that we know we are treating bacteria
0:12:49 > 0:12:54and ideally the right bacteria, will save lives every day of the week.
0:12:54 > 0:12:56We believe the technology is out there
0:12:56 > 0:12:59if only the little different bits of technology
0:12:59 > 0:13:02were put together in a black box to make it work.
0:13:05 > 0:13:08Our next nominated challenge will demand revolutionary advances
0:13:08 > 0:13:11in medical engineering but has the potential
0:13:11 > 0:13:14to transform the lives of those affected in many ways.
0:13:18 > 0:13:21Over the last few decades, our ability to help people with
0:13:21 > 0:13:26all sorts of physical disabilities has moved on in leaps and bounds.
0:13:26 > 0:13:30But our ability to help people who are paralysed doesn't go much beyond
0:13:30 > 0:13:34offering a wheelchair - just as we would have done decades ago.
0:13:34 > 0:13:38And there are 50,000 people in the UK who are paralysed.
0:13:41 > 0:13:45The loss of mobility and independence that results
0:13:45 > 0:13:50can be an enormous challenge both physically and emotionally.
0:13:50 > 0:13:53But for many people, technology can play a crucial role.
0:13:55 > 0:13:57Investigating paralysis,
0:13:57 > 0:13:59here's Dr Saleyha Ahsan.
0:14:01 > 0:14:05I'm a doctor and I used to be an army officer.
0:14:06 > 0:14:10In 1997, serving in Bosnia, I saw someone
0:14:10 > 0:14:14who had just lost their leg after stepping on a land mine.
0:14:16 > 0:14:20Watching him come to terms with the reality of his future
0:14:20 > 0:14:24as an amputee was something that I've never forgotten.
0:14:24 > 0:14:28He had this haunted, lost look on his face.
0:14:28 > 0:14:31And he knew at that moment that his life was going to be
0:14:31 > 0:14:33changed for ever.
0:14:33 > 0:14:37Of course, injuries like that are not confined to the battlefield.
0:14:39 > 0:14:43Every eight hours, someone in the UK becomes paralysed.
0:14:44 > 0:14:47I'm meeting someone who knows only too well
0:14:47 > 0:14:51how easily our lives can be changed in an instant.
0:14:52 > 0:14:54Everything that I use is in the lower cupboards.
0:14:54 > 0:14:57I can just reach some of these
0:14:57 > 0:14:59but not that easily.
0:14:59 > 0:15:01You won't reach that wasabi.
0:15:01 > 0:15:04No, don't like wasabi. The stuff I don't like is at the top!
0:15:06 > 0:15:12'Sophie has been in a wheelchair since a road accident in 2003.'
0:15:12 > 0:15:16I fractured my skull, my cheekbone,
0:15:16 > 0:15:19apparently my eye fell out of its socket.
0:15:19 > 0:15:21My jaw was broken.
0:15:21 > 0:15:25My collarbone was snapped and my spine was damaged.
0:15:25 > 0:15:27Basically, on impact I was paralysed.
0:15:27 > 0:15:32At the moment, the possibility of repairing spinal injuries,
0:15:32 > 0:15:36whether through surgery or stem cell therapy, is a long way off.
0:15:38 > 0:15:42Could engineering and robotics help instead?
0:15:43 > 0:15:46Sophie is helping to trial a remarkable new device
0:15:46 > 0:15:49designed by Richard Little.
0:15:49 > 0:15:54It offers her the chance to stand and walk independently.
0:15:54 > 0:15:57This was extremely surreal for me when I first got it.
0:15:57 > 0:16:01To be able to select the option of stand.
0:16:04 > 0:16:06LOW MECHANICAL WHIRRING
0:16:10 > 0:16:13- Gosh.- Do you feel quite steady?
0:16:13 > 0:16:15Yeah, I do, which is amazing.
0:16:15 > 0:16:18Just seeing your face now, you've really lit up.
0:16:18 > 0:16:20Can I see you walk?
0:16:20 > 0:16:22Of course you can see me walk!
0:16:37 > 0:16:40It may be slow and bulky
0:16:40 > 0:16:44but the exoskeleton can transform perspectives.
0:16:44 > 0:16:46Oh, my God. The view.
0:16:46 > 0:16:49- Had you not seen the view? - No, not seen the view. Seriously.
0:16:49 > 0:16:52- Oh, wow!- There's my car!
0:16:52 > 0:16:56I can open the window! I've not been able to do that.
0:16:58 > 0:17:00For Sophie, a practical,
0:17:00 > 0:17:04simple exoskeleton would also help her physically.
0:17:04 > 0:17:08You can live a healthy life in a wheelchair. I mean...
0:17:08 > 0:17:13But the time... The toll it takes on your body is bad.
0:17:13 > 0:17:17Small things. I've noticed a slight scoliosis in my spine
0:17:17 > 0:17:21and just from sitting because I am sitting every day all the time.
0:17:21 > 0:17:25- That'll be straightening out your core and everything.- Exactly.
0:17:25 > 0:17:30Richard, tell me about the amazing technology that's gone into this.
0:17:30 > 0:17:32It looks a simple device on the outside
0:17:32 > 0:17:36but it has 29 microcomputers on-board all talking to each other,
0:17:36 > 0:17:40managing the different systems so there's a lot goes on behind it.
0:17:40 > 0:17:45Sophie's increased mobility, the physical changes she's experienced -
0:17:45 > 0:17:49not to mention her joy - is humbling to see.
0:17:49 > 0:17:52But if paralysis is chosen to be the Longitude Prize,
0:17:52 > 0:17:56technologists will need to develop exoskeletons
0:17:56 > 0:17:58that are smaller, lighter and faster.
0:17:58 > 0:18:02The hope is also that people who can't use a joystick
0:18:02 > 0:18:05to control one could just use their thoughts.
0:18:07 > 0:18:12Doctor Tom Carlson is honing mind-control technology by trying
0:18:12 > 0:18:15to move a robot using his brainwaves.
0:18:17 > 0:18:22So, Tom, you're going to be controlling that little robot
0:18:22 > 0:18:24- with your mind.- That's right, yes.
0:18:24 > 0:18:29We've chosen 16 key electrode positions over the motor cortex.
0:18:29 > 0:18:32This is the part of the brain that deals with me
0:18:32 > 0:18:34trying to move my limbs.
0:18:34 > 0:18:38To mimic the scenario of someone who is completely paralysed,
0:18:38 > 0:18:42Tom will control the robot, not by moving his arms
0:18:42 > 0:18:45but by thinking about moving them.
0:18:45 > 0:18:47So, let's start this.
0:18:49 > 0:18:52Oh, my God. He's walking.
0:18:52 > 0:18:55As I keep this bar in the middle, the robot goes forwards,
0:18:55 > 0:18:59if I imagine moving my left hand, the bar goes to the left
0:18:59 > 0:19:04- and the robot turns left.- And that is all coming from your brain.
0:19:04 > 0:19:07- You're thinking about it.- Yes.
0:19:07 > 0:19:08That's amazing.
0:19:14 > 0:19:16Whilst you're talking to me,
0:19:16 > 0:19:19- are you still thinking about moving left and right?- Of course.
0:19:19 > 0:19:23- If I don't, the robot will be running away. - I thought men couldn't multitask!
0:19:23 > 0:19:27'It takes a lot of concentration to control the robot.'
0:19:27 > 0:19:31And you have cleverly stopped him from walking into the cupboard.
0:19:31 > 0:19:34No, he's going to go into the cupboard!
0:19:36 > 0:19:41Another problem lies in isolating Tom's directional intentions
0:19:41 > 0:19:43from the surrounding interference.
0:19:43 > 0:19:46So, these signals are very, very small.
0:19:46 > 0:19:50The scale we're looking at here is just an order of a few microvolts.
0:19:50 > 0:19:52If I clench my teeth...
0:19:52 > 0:19:53- Oh, my word.- Yes.
0:19:53 > 0:19:57They completely saturate, so when we are processing the signals
0:19:57 > 0:20:00we have to filter out all of this noise
0:20:00 > 0:20:04so we can understand what's really going on and ignore the rest.
0:20:04 > 0:20:07There's no harm in a robot bumping into a cupboard,
0:20:07 > 0:20:10but developing this technology to the point that paralysed people
0:20:10 > 0:20:16can safely control exoskeletons using their minds is a long way off.
0:20:16 > 0:20:19To get this out into the real world, onto the streets,
0:20:19 > 0:20:21I think you're looking at decades.
0:20:24 > 0:20:28As a doctor, I'm fully aware that when I have a patient
0:20:28 > 0:20:31who's paralysed, there's really little I can do for them
0:20:31 > 0:20:34apart from offer support.
0:20:34 > 0:20:37But imagine if ultimately, through robotics,
0:20:37 > 0:20:42and better understanding of the brain, we could find a way to bypass
0:20:42 > 0:20:47a broken spinal cord, and help a person to walk again.
0:20:47 > 0:20:51If paralysis is chosen as the Longitude Prize,
0:20:51 > 0:20:55the challenge will be to invent a system that gets closest to giving
0:20:55 > 0:20:59paralysed people the same freedom of movement that most of us enjoy.
0:21:00 > 0:21:02We're asking the world
0:21:02 > 0:21:04to solve the problem of paralysis.
0:21:04 > 0:21:07And the great thing is we don't tell you how to do it.
0:21:07 > 0:21:12It could be engineering. It could be neuroscience.
0:21:12 > 0:21:14It could be biology.
0:21:14 > 0:21:17You might find a new way to grow new nerves.
0:21:17 > 0:21:18We don't know.
0:21:20 > 0:21:25The next problem on our list of nominations is malnutrition,
0:21:25 > 0:21:28a subject that regularly hits the headlines.
0:21:28 > 0:21:31But the tragic events that prompt such media attention
0:21:31 > 0:21:33are just the tip of the iceberg.
0:21:35 > 0:21:37Beyond disaster-related famine,
0:21:37 > 0:21:39climate and soil type can leave people
0:21:39 > 0:21:41with permanently restricted diets.
0:21:41 > 0:21:44And of course social issues like poverty,
0:21:44 > 0:21:46education and illness play a part.
0:21:46 > 0:21:51As a result, over 800 million people around the world are undernourished,
0:21:51 > 0:21:53with children the worst affected.
0:21:53 > 0:21:56The vast majority are in developing countries,
0:21:56 > 0:21:59where one in seven of the population suffers.
0:21:59 > 0:22:01But it can affect us all.
0:22:01 > 0:22:03In fact, just here in the UK,
0:22:03 > 0:22:07over three million people are either malnourished
0:22:07 > 0:22:09or at risk of malnourishment,
0:22:09 > 0:22:12with the cost of ensuing health problems
0:22:12 > 0:22:15running into billions of pounds every year.
0:22:15 > 0:22:18Malnutrition is a problem that affects the whole planet.
0:22:18 > 0:22:23Dr Michael Mosley asks how close science is to finding a solution.
0:22:29 > 0:22:32When you hear the word malnourishment,
0:22:32 > 0:22:38you probably think of natural disasters, droughts, emergency aid.
0:22:38 > 0:22:42But, in fact, malnourishment is much wider than that.
0:22:42 > 0:22:45They may not be starving to death, but worldwide there are millions
0:22:45 > 0:22:49of people who lack vital nutrients in their diet.
0:22:49 > 0:22:53120 million don't have enough vitamin A
0:22:53 > 0:22:55and many of those will go blind.
0:22:55 > 0:22:57An astonishing billion,
0:22:57 > 0:23:02maybe two billion people around the globe are iron deficient,
0:23:02 > 0:23:06which means they feel tired and listless a lot of the time.
0:23:06 > 0:23:10If you don't get enough vitamin C in your diet, you get scurvy.
0:23:10 > 0:23:15If you don't have enough calcium or vitamin D, then you develop rickets.
0:23:16 > 0:23:19One of the biggest problems is a lack of protein
0:23:19 > 0:23:22which can cause a condition called kwashiorkor.
0:23:24 > 0:23:26Now, much of our protein comes from meat,
0:23:26 > 0:23:29but livestock farming can't feed everyone.
0:23:35 > 0:23:37One option for a more sustainable solution
0:23:37 > 0:23:40is being explored here in the Netherlands.
0:23:42 > 0:23:46Scientists have teamed up with the chef to cook me the sort of meal
0:23:46 > 0:23:49a celebrity stuck in the jungle might eat.
0:23:49 > 0:23:51- Good morning.- Good Morning.
0:23:51 > 0:23:53I like quiche, but I've never had a mealworm quiche.
0:23:53 > 0:23:56I keep on thinking they're about to wriggle, come to life.
0:23:58 > 0:24:01There's something of a novelty value to my meal.
0:24:01 > 0:24:03Thank you. Great.
0:24:03 > 0:24:07I'm going to, sort of, tuck in. Bon appetit.
0:24:08 > 0:24:12Just when I cut into it, suddenly you see them, falling out.
0:24:12 > 0:24:13Ah!
0:24:19 > 0:24:20It's delicious.
0:24:20 > 0:24:24Entomologist Marcel Dicke is serious about eating insects.
0:24:24 > 0:24:26What, sort of, is the nutritional balance?
0:24:26 > 0:24:29What have you got here in the way of fat and protein, things like that?
0:24:29 > 0:24:3350% protein, but, especially important,
0:24:33 > 0:24:37the minerals are very high - zinc, iron, magnesium.
0:24:37 > 0:24:41In terms of composition, it's similar or even better than beef.
0:24:41 > 0:24:43So I could get more iron from eating insects
0:24:43 > 0:24:46- than I could from eating beef? - Yes, definitely.
0:24:46 > 0:24:49'Insects aren't just nutritious.'
0:24:49 > 0:24:52They do provide a satisfying crunch.
0:24:52 > 0:24:54'They're more efficient to farm than livestock,
0:24:54 > 0:24:56'which makes them more sustainable.'
0:24:56 > 0:25:02For producing 1kg of beef, we need 25kg of feed.
0:25:02 > 0:25:07For producing 1kg of similar quality insect meat,
0:25:07 > 0:25:10you need only 2.2kg of feed.
0:25:10 > 0:25:12- Right, so that's 10%.- Only 10%.
0:25:12 > 0:25:17'Marcel's team helped compile a UN report showing that farmed insects
0:25:17 > 0:25:21'produced fewer greenhouse gases and less ammonia than cattle.'
0:25:21 > 0:25:23'They need less water and land, too.
0:25:23 > 0:25:28'And 20,000 insect farms in Thailand show it can be done cheaply.
0:25:29 > 0:25:31'The numbers all add up,
0:25:31 > 0:25:34'but there is still one thing getting in the way.'
0:25:34 > 0:25:38Well, the major barrier in the Western world is here,
0:25:38 > 0:25:43psychological, people need to get used to it and I understand that.
0:25:43 > 0:25:47If food technologists could find a way round our squeamishness,
0:25:47 > 0:25:50insects might become more than a curiosity in the West.
0:25:52 > 0:25:55But they aren't our only hope.
0:25:55 > 0:25:57When it comes to easing global malnutrition,
0:25:57 > 0:26:00there is one area of research where the potential is almost limitless,
0:26:00 > 0:26:04and where they have recently also made huge advances.
0:26:04 > 0:26:08Unfortunately, it is also incredibly contentious.
0:26:08 > 0:26:10It is the genetic modification of crops.
0:26:12 > 0:26:16In the US, more than 80% of corn, soya bean and cotton
0:26:16 > 0:26:19produced in 2013 was genetically modified.
0:26:21 > 0:26:25Here in the UK, you'd be pushed to find any GM food in the shops.
0:26:25 > 0:26:27But there's lots of research going on,
0:26:27 > 0:26:30because, as well as increasing yield,
0:26:30 > 0:26:33GM can make food more nutritious.
0:26:33 > 0:26:35This is Rothamsted Research.
0:26:35 > 0:26:39Now, it is the longest running agricultural research station
0:26:39 > 0:26:40in the world,
0:26:40 > 0:26:44and the aim of this place is to get the most out of the crops we grow.
0:26:46 > 0:26:50This remarkable Camelina plant contains omega-3 fish oil,
0:26:50 > 0:26:54a vital nutrient thought to protect against heart disease and cancer
0:26:54 > 0:26:57and to assist brain function.
0:26:57 > 0:26:59Now, it isn't found naturally in plants.
0:26:59 > 0:27:02But it is found in oily fish like salmon.
0:27:02 > 0:27:04That's the root of a major problem,
0:27:04 > 0:27:07which Johnathan Napier is trying to solve.
0:27:07 > 0:27:09The global fish stocks that we have at the moment
0:27:09 > 0:27:12are sufficient to provide our population,
0:27:12 > 0:27:17our seven billion mouths, with about a teaspoon full of fish oil a week,
0:27:17 > 0:27:21whereas we probably need at least double that, maybe more.
0:27:21 > 0:27:24The situation's so bad that a recent US survey attributed
0:27:24 > 0:27:28over 80,000 deaths a year to fish oil deficiencies.
0:27:30 > 0:27:32So we're interested in trying to develop
0:27:32 > 0:27:35an alternative, sustainable source of fish oils.
0:27:35 > 0:27:38And these are our GM Camelina plants that we've engineered
0:27:38 > 0:27:41to accumulate omega-3 fish oils.
0:27:41 > 0:27:42Now that is pretty weird.
0:27:42 > 0:27:45So this, presumably, this is the oil you produce, is it?
0:27:45 > 0:27:46- Yeah, so...- How much is this?
0:27:46 > 0:27:49I think in terms of the amount of time and effort to produce it,
0:27:49 > 0:27:52- it's tens if not hundreds of thousands of pounds.- Per litre?
0:27:52 > 0:27:55- Oh, yeah.- You'll have to get the price down before you sell it.
0:27:55 > 0:27:57Can I have a sniff? I promise not to swallow.
0:27:57 > 0:28:00- You can have a sniff of it, as long as you don't...- Not to taste, yeah.
0:28:00 > 0:28:03Hold it to your lips and drain it. I would...
0:28:03 > 0:28:05It's not at all fishy.
0:28:05 > 0:28:07I mean, it's, sort of, if anything, slightly cabbagy.
0:28:07 > 0:28:09Camelina is a brassica species
0:28:09 > 0:28:11and so it would have a slightly cabbagy smell.
0:28:11 > 0:28:15It is very strange, realising that I hold in my hands there
0:28:15 > 0:28:19something that could have quite a significant impact on the future.
0:28:19 > 0:28:22There are years of field trials and legal debate ahead
0:28:22 > 0:28:24for crops like this.
0:28:24 > 0:28:27But it does show what could be achieved.
0:28:29 > 0:28:32I have seen two very different approaches
0:28:32 > 0:28:34to the problem of malnutrition -
0:28:34 > 0:28:37genetically-modified crops and insects.
0:28:37 > 0:28:40Now, both could contribute significantly in the future
0:28:40 > 0:28:42or perhaps solutions will come from
0:28:42 > 0:28:46some completely unrelated area of research.
0:28:47 > 0:28:51By 2050, there'll be nine billion people on the planet.
0:28:51 > 0:28:54To feed them, we need to double food production.
0:28:56 > 0:28:59Vote for food to be the subject of the Longitude Prize
0:28:59 > 0:29:02and the challenge will be to create a historic innovation.
0:29:02 > 0:29:06Something that offers everyone enough to eat that's nutritious,
0:29:06 > 0:29:08sustainable and delicious.
0:29:10 > 0:29:11It could be immensely exciting.
0:29:11 > 0:29:13You know, we're talking about innovations that could
0:29:13 > 0:29:16change the world, and if you look at the history of innovations in food,
0:29:16 > 0:29:18you think about things like irrigation,
0:29:18 > 0:29:20things like refrigeration,
0:29:20 > 0:29:22things like fertilisers, industrial fertilisers.
0:29:22 > 0:29:24These have quite literally changed the world
0:29:24 > 0:29:26and changed the way the human race has developed.
0:29:30 > 0:29:33One thing that links each of the nominated problems
0:29:33 > 0:29:36is that a world-changing solution
0:29:36 > 0:29:38needn't come from renowned scientists.
0:29:38 > 0:29:40Back in the 18th century,
0:29:40 > 0:29:43as astronomers struggled to solve the Longitude problem,
0:29:43 > 0:29:47the Board appealed to the British public for help.
0:29:47 > 0:29:50And that was where a man named John Harrison came in.
0:29:50 > 0:29:53He wasn't from a university, or a big engineering company -
0:29:53 > 0:29:58he was a lone carpenter and clock-maker from Yorkshire.
0:29:58 > 0:30:02Harrison was convinced the solution to the problem lay
0:30:02 > 0:30:06not in astronomy, but in inventing a clock
0:30:06 > 0:30:09that would keep perfect time at sea.
0:30:13 > 0:30:16I've come to the Horology Workshop at Greenwich,
0:30:16 > 0:30:19to find out how he solved the problem -
0:30:19 > 0:30:23with his revolutionary Marine Chronometer, H4.
0:30:23 > 0:30:25- This is H4.- This is H4.
0:30:27 > 0:30:32Wonderful, it does look like an oversized pocket watch.
0:30:32 > 0:30:34Absolutely.
0:30:34 > 0:30:36People are often confused,
0:30:36 > 0:30:39thinking it would've been worn in an enormous waistcoat pocket.
0:30:39 > 0:30:45This wasn't Harrison's first attempt to solve the problem.
0:30:45 > 0:30:46For over 25 years,
0:30:46 > 0:30:50he'd set his sights on designing a clock that could handle
0:30:50 > 0:30:55life at sea. After all, watches at the time were hopelessly inaccurate.
0:30:56 > 0:31:00It was to Harrison's great credit that he was the one who
0:31:00 > 0:31:05realised that was the wrong course and that he needed to rethink
0:31:05 > 0:31:09the technology completely, that's when he started looking at watches.
0:31:09 > 0:31:13He asked himself - why don't watches keep time well? And he realised
0:31:13 > 0:31:17there was a very specific reason and that he could get round that reason.
0:31:17 > 0:31:20- Would you like me to open it up and show you?- Yes, please.
0:31:27 > 0:31:29It's very exciting to see this.
0:31:29 > 0:31:31It's beautiful.
0:31:33 > 0:31:36If you think that's beautiful, prepare to be astonished.
0:31:36 > 0:31:38It's a wonderful thing.
0:31:38 > 0:31:39Oh! Wow! Look at that.
0:31:41 > 0:31:45- Isn't that something? - Incredible! That's really beautiful.
0:31:48 > 0:31:51It's OK to start it if you'd like to hear it?
0:31:51 > 0:31:52Yes, please.
0:31:57 > 0:31:58I won't wind it very much.
0:32:00 > 0:32:01That should do it...
0:32:01 > 0:32:05To start it, you have to give it a swift swing...
0:32:07 > 0:32:10There it goes. Yeah.
0:32:10 > 0:32:11Wow!
0:32:15 > 0:32:19So what was so special about the timekeeper,
0:32:19 > 0:32:22- what was Harrison's breakthrough? - His improvement was
0:32:22 > 0:32:27the specification of the large oscillating wheel, the balance.
0:32:27 > 0:32:29In a clock, the oscillator is the pendulum,
0:32:29 > 0:32:34but in a watch, the oscillator is a little wheel that swings to and fro.
0:32:34 > 0:32:38- You can see it flashing away through the holes in the engraving.- Yeah.
0:32:38 > 0:32:41Harrison was the first to recognise that with this balance
0:32:41 > 0:32:43you needed to have large swings,
0:32:43 > 0:32:47that is, not just swinging through a few degrees,
0:32:47 > 0:32:50but big circles of swings, if you get me,
0:32:50 > 0:32:54and also fast, it has to swing very fast.
0:32:54 > 0:32:58In H4 the balance swings five times a second,
0:32:58 > 0:33:00so that's really thrashing away in there.
0:33:00 > 0:33:02So moving it around on a ship
0:33:02 > 0:33:06you're not going to disturb that movement in the clock?
0:33:06 > 0:33:10Yes, but received wisdom was you must not do this.
0:33:10 > 0:33:15Every trained professional watchmaker had been told as an apprentice
0:33:15 > 0:33:17never design a watch like this.
0:33:17 > 0:33:23So Harrison was knowingly going against perceived wisdom,
0:33:23 > 0:33:28so it required someone prepared to think completely outside the box
0:33:28 > 0:33:29to enable him to succeed.
0:33:33 > 0:33:37On its maiden voyage to the West Indies, after nine weeks at sea,
0:33:37 > 0:33:41Harrison's clock was accurate to within just five seconds,
0:33:41 > 0:33:45well inside the target of almost two minutes for such a journey.
0:33:45 > 0:33:50And though it was several more years before he convinced the Board
0:33:50 > 0:33:53that H4 wasn't a fluke, he finally received
0:33:53 > 0:33:57over £23,000 in prize money, rewarding 43 years of work.
0:33:59 > 0:34:02Thanks to John Harrison's clocks,
0:34:02 > 0:34:05countless lives have been saved at sea ever since.
0:34:05 > 0:34:08It really was a world-changing innovation.
0:34:08 > 0:34:12It cemented Britain's position as a global power, allowing sea trade
0:34:12 > 0:34:14to flourish, and played a part
0:34:14 > 0:34:19in fixing Greenwich at the centre of world time once and for all.
0:34:19 > 0:34:24This is the international meridian or zero longitude line.
0:34:24 > 0:34:27Now I'm in the Western hemisphere,
0:34:27 > 0:34:29over here I'm in the Eastern hemisphere.
0:34:32 > 0:34:36300 years ago, a clockmaker from Yorkshire changed the world.
0:34:36 > 0:34:41Can the new Longitude Prize inspire someone else to do the same?
0:34:46 > 0:34:49In its report published in April this year,
0:34:49 > 0:34:52the Intergovernmental Panel on Climate Change made it clear
0:34:52 > 0:34:55that the world faces an enormous challenge.
0:34:55 > 0:34:58If we're to avoid dangerous climate change in the 21st century,
0:34:58 > 0:35:03we need to cut global greenhouse gas emissions by 70%.
0:35:05 > 0:35:08The effects of climate change are already being felt.
0:35:08 > 0:35:11And by raising sea levels, changing our weather patterns,
0:35:11 > 0:35:14and affecting our ability to grow food,
0:35:14 > 0:35:18climate change will leave its mark on all of us.
0:35:18 > 0:35:20And there'll be no single solution to this problem -
0:35:20 > 0:35:24it will demand multiple technological innovations.
0:35:24 > 0:35:27Most urgently we need to tackle the world's top three
0:35:27 > 0:35:31sources of emissions - energy, industry and transport,
0:35:31 > 0:35:35which alone accounts for 13% of emissions.
0:35:35 > 0:35:38Dr Helen Czerski is investigating flight.
0:35:43 > 0:35:47Ten years ago this would've been a revolutionary vehicle.
0:35:47 > 0:35:51Because this is an electric car.
0:35:54 > 0:35:58Today, electric cars are entering the mainstream.
0:35:59 > 0:36:04Offering the potential for road travel to be carbon-free.
0:36:14 > 0:36:16But one form of transport is miles behind
0:36:16 > 0:36:20when it comes to low carbon innovation.
0:36:24 > 0:36:26And that is air travel.
0:36:26 > 0:36:29If you're in one of those, you know you're burning jet fuel.
0:36:29 > 0:36:33And there are tonnes of carbons belching from those engines.
0:36:33 > 0:36:36If we're going to hit current emissions targets,
0:36:37 > 0:36:41just one return flight across the Atlantic would use up
0:36:41 > 0:36:44a passenger's entire annual carbon budget.
0:36:44 > 0:36:46To keep up with our appetite for flight,
0:36:46 > 0:36:49we need a low carbon alternative.
0:36:58 > 0:37:00There aren't many yet.
0:37:01 > 0:37:03But in Slovenia,
0:37:03 > 0:37:05one family-owned company has been
0:37:05 > 0:37:09experimenting with carbon-free flight, on a small scale.
0:37:09 > 0:37:10Launched in 2012,
0:37:10 > 0:37:15The Taurus Electro won't be replacing Jumbo jets any time soon,
0:37:15 > 0:37:19but it's one of the most eco-friendly planes in the world.
0:37:19 > 0:37:22What is it that's so special about this plane?
0:37:22 > 0:37:27Well, there's no fuel involved with this aeroplane at all.
0:37:27 > 0:37:30it's an electric-powered aeroplane that takes energy
0:37:30 > 0:37:34from the battery and moves about by using this little electric motor.
0:37:34 > 0:37:37- This is the battery. - It's really small!
0:37:37 > 0:37:38It's really small!
0:37:38 > 0:37:40It may seem small, but it carries
0:37:40 > 0:37:42about tenfold of what a car battery would -
0:37:42 > 0:37:44and it's only three times the size.
0:37:44 > 0:37:48In fact we're using the highest energy density batteries
0:37:48 > 0:37:50that are available on the market.
0:37:50 > 0:37:52We're starting to see lots of electric cars on the road,
0:37:52 > 0:37:54why aren't there more electric aircraft?
0:37:54 > 0:37:59Because it's much more difficult - the aeroplane has to lift the weight
0:37:59 > 0:38:02of the battery pack, plus the aeroplane and the people up aloft.
0:38:05 > 0:38:08Well, let's see what it can do.
0:38:11 > 0:38:14OK, electric aircraft, here we go.
0:38:32 > 0:38:33It's so smooth.
0:38:38 > 0:38:41The batteries contain enough power to get the aircraft up to
0:38:41 > 0:38:43an altitude of 2,500 metres.
0:38:43 > 0:38:47At which point we go into economy mode.
0:38:47 > 0:38:50ENGINE DROPS OFF
0:38:50 > 0:38:52- Oh, God.- Stop the engine.
0:38:53 > 0:38:54SHE LAUGHS NERVOUSLY
0:38:54 > 0:38:57I wasn't expecting that!
0:38:57 > 0:39:00- Actually, now we are a glider. - Right!
0:39:00 > 0:39:04At the push of a button, the engine shuts down, the propeller tucks away,
0:39:04 > 0:39:07and the plane becomes a glider.
0:39:08 > 0:39:11It really is carbon-free flight.
0:39:14 > 0:39:17But with only an hour or so's battery life in total,
0:39:17 > 0:39:21you can't get very far without thermals providing extra lift.
0:39:21 > 0:39:25That's no use for a passenger plane which needs to fly
0:39:25 > 0:39:27anywhere in the world.
0:39:27 > 0:39:31And bigger batteries would just add weight and demand even more power.
0:39:35 > 0:39:38The flight today was just two people on a fun trip,
0:39:38 > 0:39:39but what we want
0:39:39 > 0:39:43is to transport hundreds of people for hundreds of miles.
0:39:43 > 0:39:46And the problem with scaling up this technology is that
0:39:46 > 0:39:50the best batteries we can foresee just can't do that job.
0:39:52 > 0:39:55Another approach to the problem might be to abandon batteries
0:39:55 > 0:39:58and explore completely new power systems.
0:40:00 > 0:40:04Like those being developed to drive the next generation of spacecraft.
0:40:07 > 0:40:10ENGINE ROARS
0:40:10 > 0:40:11Here in Oxfordshire,
0:40:11 > 0:40:15a team of engineers are developing a revolutionary engine.
0:40:15 > 0:40:20Its fuel has greater energy density than batteries or fossil fuels.
0:40:20 > 0:40:22It runs on liquid hydrogen.
0:40:23 > 0:40:26How much better is hydrogen than other available fuels?
0:40:26 > 0:40:29It's about two-and-a-half times the calorific value
0:40:29 > 0:40:31per kilogram of a hydrocarbon.
0:40:31 > 0:40:34Which means that gives you the best fuel consumption
0:40:34 > 0:40:36possible for the engine.
0:40:36 > 0:40:38This isn't just about getting into space,
0:40:38 > 0:40:41you can use these ideas for commercial flight as well.
0:40:41 > 0:40:45Yes, and such a vehicle could fly halfway round the world at Mach 5,
0:40:45 > 0:40:48which would reduce the journey time
0:40:48 > 0:40:52to Australia from something like 24 hours down to about four-and-a-half.
0:40:52 > 0:40:54You'll just have time to drink a few gin and tonics
0:40:54 > 0:40:56and watch the movie, then you'll land.
0:40:56 > 0:41:01So it's got the power for a passenger plane, but the real bonus is
0:41:01 > 0:41:06that burning hydrogen leaves an exhaust of almost pure water vapour.
0:41:06 > 0:41:10So why isn't hydrogen used to power our planes normally?
0:41:10 > 0:41:13Because it's incredibly expensive is the simple answer.
0:41:13 > 0:41:15You've got to make the hydrogen somehow,
0:41:15 > 0:41:16and then you have to liquefy it.
0:41:16 > 0:41:19And the liquefaction absorbs a lot of energy,
0:41:19 > 0:41:22and that makes it very expensive.
0:41:23 > 0:41:26Sadly, it's not just the cost.
0:41:26 > 0:41:31To make hydrogen fuel in the first place relies mostly on fossil fuels.
0:41:31 > 0:41:33And that means carbon emissions.
0:41:33 > 0:41:37We need a cheap, clean hydrogen source before this technology
0:41:37 > 0:41:40can truly offer carbon-free passenger flight.
0:41:43 > 0:41:47It's just over 100 years since humans first achieved powered flight,
0:41:47 > 0:41:52and for all of that time it's been powered by fossil fuels.
0:41:52 > 0:41:55But now, there are hints that it could be different.
0:41:55 > 0:41:59There are new ideas - battery technologies, hydrogen, biofuels -
0:41:59 > 0:42:03and all we need is a spark that will take us on
0:42:03 > 0:42:08to a revolution in air travel and give us carbon-free flight.
0:42:10 > 0:42:14If you choose this problem as the subject of the Longitude Prize,
0:42:14 > 0:42:17the winner would need to build a plane that can fly from London
0:42:17 > 0:42:21to Edinburgh at a comparable speed to today's planes -
0:42:21 > 0:42:23with no carbon emissions.
0:42:24 > 0:42:26The selection of flight was partly
0:42:26 > 0:42:29motivated by the fact that it is a challenge that can be
0:42:29 > 0:42:33addressed by small groups of creative individuals.
0:42:33 > 0:42:35It doesn't require vast resources
0:42:35 > 0:42:38to try and make a different sort of aircraft.
0:42:42 > 0:42:45The world's population is still growing at an alarming rate.
0:42:45 > 0:42:48In fact, there are nearly twice as many people
0:42:48 > 0:42:51alive on the planet today as there were when I was born,
0:42:51 > 0:42:55placing the planet's precious natural resources
0:42:55 > 0:42:57under ever-increasing pressure.
0:42:57 > 0:43:01In its 2014 report, the Intergovernmental Panel on Climate Change
0:43:01 > 0:43:04identified the supply of fresh water
0:43:04 > 0:43:08to the global population as an area of major concern,
0:43:08 > 0:43:12and the World Health Organisation has predicted that by 2025
0:43:12 > 0:43:17half of the world's population will be living in water-stressed areas.
0:43:18 > 0:43:21Professor Iain Stewart is looking at the immense challenge
0:43:21 > 0:43:24of supplying the world with fresh water.
0:43:31 > 0:43:34There's a reason we call Earth the Blue Planet.
0:43:34 > 0:43:36There's a lot of water on it.
0:43:36 > 0:43:39Something like a billion trillion litres in fact.
0:43:39 > 0:43:42Of course, only a tiny proportion of that is water clean enough
0:43:42 > 0:43:45that you can drink or put on your crops.
0:43:45 > 0:43:5097% of it is sea water, full of salt.
0:43:50 > 0:43:53And if you try and drink that, the consequences can be fatal.
0:43:57 > 0:44:00The obvious solution is to convert this vast water resource
0:44:00 > 0:44:04into something you can drink, by separating the water from the salt.
0:44:04 > 0:44:07But that isn't quite as easy as it sounds.
0:44:10 > 0:44:15So this is a solar still, which is designed to take the heat
0:44:15 > 0:44:19of the sun and convert dirty, salty water into lovely drinking water.
0:44:22 > 0:44:26It's basically an inflatable bag, and I'm going to fill it with
0:44:26 > 0:44:31a blend of water, salt and coffee for an authentic muddy look.
0:44:32 > 0:44:34I know it doesn't look nice.
0:44:34 > 0:44:36But now we just let the sun do its work.
0:44:39 > 0:44:43Under the sun's heat, pure water evaporates inside.
0:44:43 > 0:44:47It condenses on the lid, and eventually collects in the bag.
0:44:49 > 0:44:52Of course, there's only one real test of all of this.
0:44:58 > 0:45:01Well, that's all right really. But actually, there's not a lot of it.
0:45:01 > 0:45:04We've had about five hours of pretty constant sunshine.
0:45:04 > 0:45:05And that's the problem really.
0:45:05 > 0:45:08Generating fresh water from saltwater using just
0:45:08 > 0:45:12the energy of the sun is a slow business.
0:45:12 > 0:45:16It might be OK for occasional use, but for a permanent supply,
0:45:16 > 0:45:17we need a lot more energy.
0:45:20 > 0:45:24Even here in London engineers are turning to sea water
0:45:24 > 0:45:26to boost dwindling water supplies.
0:45:27 > 0:45:31This is one of the most advanced desalination plants in the world.
0:45:33 > 0:45:35This is where it all starts. This is the Thames.
0:45:35 > 0:45:38London is up there, and the sea's down here,
0:45:38 > 0:45:41so this water is really pretty salty.
0:45:41 > 0:45:45The water itself gets sucked up by these huge pipes here,
0:45:45 > 0:45:48up to 220 million litres every day.
0:45:51 > 0:45:56Once all the muck has been filtered out, the real job begins.
0:45:56 > 0:46:00But instead of evaporation, this place relies on pure brute force.
0:46:00 > 0:46:03So, Simon, how do you get the salt out of the water?
0:46:03 > 0:46:06We've got to force the water from the salty solution,
0:46:06 > 0:46:09and we use these membranes to do that.
0:46:09 > 0:46:13So these rolls here...is kind of what's in these tubes, is it?
0:46:13 > 0:46:16Absolutely, we've got about 10,000 of these on site.
0:46:16 > 0:46:19And that's exactly what's in each one of these tubes.
0:46:19 > 0:46:21So how does this work then?
0:46:21 > 0:46:22So you've got the salty solution,
0:46:22 > 0:46:25and it works its way through the membrane,
0:46:25 > 0:46:28and really, you get the clean water coming out through the centre.
0:46:28 > 0:46:29So this is where it ends up then, is it?
0:46:29 > 0:46:31- Down that kind of tube there? - Absolutely.
0:46:33 > 0:46:37The system is fighting against a natural process called osmosis,
0:46:37 > 0:46:42which normally drives water INTO salty solutions, not out of them.
0:46:42 > 0:46:45It's fighting that process that takes all the effort.
0:46:45 > 0:46:48So, if you think, the normal pressure
0:46:48 > 0:46:50- in a car tyre is about, what, two bar?- Yeah.
0:46:50 > 0:46:54This is about 84 bar - 40 times higher, the pressure,
0:46:54 > 0:46:56to force the salty solution against this.
0:46:56 > 0:46:59It's the cost of actually providing the pressure behind that,
0:46:59 > 0:47:00that's the challenge.
0:47:02 > 0:47:06At these pressures, the valuable membranes quickly clog up with dirt,
0:47:06 > 0:47:09making drinking water from here around about 15 times
0:47:09 > 0:47:11more expensive than regular water.
0:47:13 > 0:47:16We desperately need a cheaper, more efficient way
0:47:16 > 0:47:17to convert large volumes.
0:47:19 > 0:47:21No-one's found the answer yet.
0:47:23 > 0:47:27But here in Gibraltar, engineers are trying something new.
0:47:30 > 0:47:34- Peter?- Yes?- Hi. - You must be Iain.
0:47:34 > 0:47:37'This new system separates salt from water by
0:47:37 > 0:47:40'taking advantage of osmosis, rather than fighting it.
0:47:40 > 0:47:42'And it can handle 18,000 litres a day.'
0:47:44 > 0:47:46So what's actually going on inside?
0:47:46 > 0:47:48If we could cut one of them open, what would we see?
0:47:48 > 0:47:52What you'd see inside of these is some hollow fibres.
0:47:52 > 0:47:55- So this is a hollow fibre membrane. - These are tubes?
0:47:55 > 0:47:59- These are tubes. Very, very fine.- Oh, like hair.
0:47:59 > 0:48:03Sea water flows on the outside of these fibres,
0:48:03 > 0:48:07and through the fibres we pump what we call draw solution.
0:48:08 > 0:48:10'That draw solution's the key,
0:48:10 > 0:48:13'because it's more concentrated than sea water.'
0:48:13 > 0:48:15So, by the natural process of osmosis,
0:48:15 > 0:48:18we draw across, effectively, almost pure water.
0:48:18 > 0:48:21I guess the point is that there's really no energy involved.
0:48:21 > 0:48:24In this step there's very little, it just happens naturally.
0:48:25 > 0:48:29'It's a step forwards, although for now, they still need to use
0:48:29 > 0:48:33'pressure to separate the water from the draw solution.
0:48:33 > 0:48:36'Overall, it's more efficient, but only just.'
0:48:39 > 0:48:40OK, so let's have a...
0:48:42 > 0:48:45- Slightly nervous!- Shouldn't be.
0:48:47 > 0:48:49No, that's really nice.
0:48:50 > 0:48:54'New systems like this are setting the scene for a revolution
0:48:54 > 0:48:57'in water treatment, but the real goal is still a long way off.'
0:48:59 > 0:49:02So the big question is, is there an even better way
0:49:02 > 0:49:06to take the almost limitless supplies of that stuff
0:49:06 > 0:49:08and turn it into water we can use?
0:49:11 > 0:49:15'Fresh water is increasingly precious yet essential.
0:49:15 > 0:49:18'If this is the problem you choose as the most important to tackle,
0:49:18 > 0:49:22'then the prize will be awarded to whoever can create a cheap
0:49:22 > 0:49:25'and environmentally sustainable technology
0:49:25 > 0:49:28'to produce fresh water anywhere in the world.'
0:49:29 > 0:49:31You just have to read headlines,
0:49:31 > 0:49:34whether it's in Beijing or California and so on,
0:49:34 > 0:49:38to know that the existing fresh water infrastructure is
0:49:38 > 0:49:42really under colossal strain and we need some radical
0:49:42 > 0:49:47new approaches to plumb the planet in a fundamentally different way.
0:49:49 > 0:49:53An undeniable benefit of modern medicine is that all of us
0:49:53 > 0:49:55can expect to live longer.
0:49:55 > 0:49:59But an ageing population brings challenges of its own,
0:49:59 > 0:50:03in particular the task of caring for those living with dementia,
0:50:03 > 0:50:07including its most common form, Alzheimer's disease.
0:50:07 > 0:50:10According to the Alzheimer's Society the number of people living with
0:50:10 > 0:50:13the disease is set to double in the next 25 years,
0:50:13 > 0:50:17placing an immense burden not just on the healthcare system
0:50:17 > 0:50:21but on individuals, on their families and care networks.
0:50:23 > 0:50:27'As many as 50,000 people are expected to leave work this year
0:50:27 > 0:50:30'to cope with the demands of caring for sufferers.
0:50:32 > 0:50:35'Finally, Dr Kevin Fong investigates how technology
0:50:35 > 0:50:38'might also help with this imminent crisis.'
0:50:41 > 0:50:45- Hello!- Hello!- Hello, how are you? - Fine, good, come in. Do come in.
0:50:47 > 0:50:49'I've come to see Anne Delve.'
0:50:49 > 0:50:51- Anne.- Hello, nice to see you.
0:50:51 > 0:50:54'Five years ago, she was diagnosed with dementia.'
0:50:54 > 0:50:57Things aren't quite right sometimes
0:50:57 > 0:51:02but you have to get that in the right place in the head.
0:51:03 > 0:51:07'Her sister Joy has moved in to give her constant care,
0:51:07 > 0:51:09'and their mother Joan also helps.'
0:51:10 > 0:51:14For Anne, I think knowing that she was ill was hard initially,
0:51:14 > 0:51:17but also, when you've got to accept that you've got to have help,
0:51:17 > 0:51:21as with anyone with any kind of illness, it's really hard.
0:51:21 > 0:51:24Yeah, because, I used to...
0:51:24 > 0:51:27- used to go anywhere.- Mm.
0:51:27 > 0:51:31Erm, but, you know, that's how things are.
0:51:31 > 0:51:33It's the loss of independence, isn't it?
0:51:35 > 0:51:40'For people with dementia, even simple chores can become difficult,
0:51:40 > 0:51:43'as memory fades and decision-making gets harder.
0:51:44 > 0:51:47'But encouraging the keep-up of everyday tasks
0:51:47 > 0:51:50'can help slow the decline.
0:51:50 > 0:51:52- You've got the tap here for the sink.- Yeah.
0:51:52 > 0:51:54- D'you remember how to turn it on? - No.
0:51:54 > 0:51:56If you want to turn the tap on,
0:51:56 > 0:52:00you'd use the little switch here, d'you remember? Just over there?
0:52:00 > 0:52:03You can do that, and pull it towards you. Just pull it.
0:52:03 > 0:52:06- I suppose I could.- Give it a go. - I'm not going to burn myself.
0:52:06 > 0:52:08No, that's cold water.
0:52:08 > 0:52:12- And then you can wash the cups up for me, is that all right?- Yes, yes.
0:52:12 > 0:52:13- You don't mind, do you?- No.
0:52:15 > 0:52:19- Shall I wash this off now, then? - Yes, Anne.- Leave this on here?
0:52:19 > 0:52:23Do you want to put it on the drainer? That's it, Anne, brilliant.
0:52:23 > 0:52:27'While many people with dementia have to move into care homes,
0:52:27 > 0:52:32'sufferers are normally much better off in a familiar environment.'
0:52:32 > 0:52:34It seems important for you that you're at home and not
0:52:34 > 0:52:37- somewhere else... - I think so, definitely.
0:52:37 > 0:52:39- ..being looked after by strangers. - Yes, definitely.
0:52:39 > 0:52:42That is great for Anne's health and her wellbeing
0:52:42 > 0:52:46because we're carrying on doing what is normal in the home.
0:52:46 > 0:52:50'But this sort of care can be a huge burden on the family,
0:52:50 > 0:52:53'so the hope is that technology might offer help.
0:52:55 > 0:52:57'At Birmingham University,
0:52:57 > 0:53:00'researchers are one step closer to the ultimate answer.
0:53:02 > 0:53:04'A robot carer. He's called Bob.'
0:53:04 > 0:53:06Bob can learn, in somebody's home,
0:53:06 > 0:53:10where they typically leave their newspaper or their slippers or
0:53:10 > 0:53:14their keys, and use the information so he can quickly find things.
0:53:14 > 0:53:15Object located.
0:53:15 > 0:53:17And you can see that what he's done is
0:53:17 > 0:53:19he's found the keyboard and a bottle.
0:53:19 > 0:53:22Bob can monitor the positions of people,
0:53:22 > 0:53:25so we're looking to detect, has someone fallen over?
0:53:25 > 0:53:27And also remind people or notify carers that someone's
0:53:27 > 0:53:31forgotten to take their medicine or they haven't got up at the time they should,
0:53:31 > 0:53:33or they're getting up at the time they shouldn't,
0:53:33 > 0:53:36so they've gone out and walked around in the middle of the night.
0:53:36 > 0:53:40'With today's technology, Bob's abilities are restricted.
0:53:40 > 0:53:43'Stairs are a problem, it doesn't have useful arms yet,
0:53:43 > 0:53:46'and its decision-making is limited.
0:53:46 > 0:53:50'For now, domestic robots are still the stuff of science fiction.'
0:53:50 > 0:53:53Of course, these things are a very long way away.
0:53:53 > 0:53:55Things are maturing at different rates in robotics,
0:53:55 > 0:53:59but one day we'll be able to put these things together.
0:53:59 > 0:54:02'Another approach scientists are exploring
0:54:02 > 0:54:05'is to make the home itself part of the caring system.'
0:54:05 > 0:54:08Pretty ordinary looking kitchen. Tell me what's special about it.
0:54:08 > 0:54:11OK, so, physically it's meant to be unremarkable in that it's
0:54:11 > 0:54:15meant to be like the sort of kitchen you might have in an everyday home.
0:54:15 > 0:54:19We've got sensors in the utensils, sensors in the appliances
0:54:19 > 0:54:21and sensors in the worktops themselves to give you
0:54:21 > 0:54:24a little bit of a nudge at an appropriate time.
0:54:24 > 0:54:28Well, let's have a look at making a cup of tea in this automated kitchen.
0:54:28 > 0:54:29So, kettle on.
0:54:29 > 0:54:32The kettle itself has a sensor in that measures how much water
0:54:32 > 0:54:35is in there, so it knows that you've got enough for a cup of tea.
0:54:35 > 0:54:37The cups have a sensor in.
0:54:37 > 0:54:39Open the tea caddy to get a teabag.
0:54:39 > 0:54:42And as you've just seen there, our environment's reasoned
0:54:42 > 0:54:45that our kettle's boiled, our cup's out, we're making a cup of tea.
0:54:45 > 0:54:47And it knows that we want to go for a teabag,
0:54:47 > 0:54:50and I'm assuming you can't instrument that as well.
0:54:50 > 0:54:52Well, actually, we do in this case.
0:54:52 > 0:54:55So we use sensors in the teabag's tag here.
0:54:55 > 0:54:57Pour hot water into the cup.
0:54:57 > 0:55:01'With sensors attached to everything I need to make a cuppa,
0:55:01 > 0:55:04'the computer guides me through every step...'
0:55:04 > 0:55:06Pour some milk into the cup.
0:55:06 > 0:55:09- OK.- There you go.- It wants me to get on with making your tea, yeah.
0:55:09 > 0:55:13'..and monitors what I'm doing all the way.'
0:55:13 > 0:55:15And so it knows that that's a stirring action,
0:55:15 > 0:55:18it's seeing that through the motion of the accelerometer.
0:55:18 > 0:55:20Whereas if you put the sensor down...
0:55:20 > 0:55:23- I'll just leave it there.- ..it'll know that you're not stirring.
0:55:23 > 0:55:25That's pretty impressive.
0:55:25 > 0:55:30'This system gives us a glimpse of what technology could make possible.
0:55:30 > 0:55:32'But the reality is it doesn't yet have
0:55:32 > 0:55:36'the artificial intelligence needed to replace a human carer.'
0:55:38 > 0:55:40Dementia is one of the most difficult
0:55:40 > 0:55:44and devastating problems that we face in science and society today.
0:55:44 > 0:55:49We're a long way from any meaningful treatment, much less a cure.
0:55:49 > 0:55:52But in the meantime there's the hope that technology might allow us
0:55:52 > 0:55:57to live our lives as fully as possible for as long as possible.
0:55:57 > 0:55:58- Come on.- All right.
0:55:58 > 0:56:02'Most of us will know someone with some form of dementia
0:56:02 > 0:56:06'during our lives, and it's a growing problem.
0:56:06 > 0:56:07'If this gets your vote,
0:56:07 > 0:56:10'then the challenge to potential winners will be to develop
0:56:10 > 0:56:15'an affordable technology that's truly capable of giving independence
0:56:15 > 0:56:17'to people living with the condition.'
0:56:17 > 0:56:22It's a cruel disease, as you watch the person you love change,
0:56:22 > 0:56:26and you lose them, but you still want to support them.
0:56:26 > 0:56:30We can't throw the money at a human caring system, so we need to think
0:56:30 > 0:56:36about how we can use technology and smart devices to enable them
0:56:36 > 0:56:39to live on their own with dignity for longer.
0:56:42 > 0:56:46Carbon free flight, paralysis or food?
0:56:46 > 0:56:50Dementia care, fresh water or antibiotics?
0:56:52 > 0:56:55'Six vital problems facing us today,
0:56:55 > 0:57:00'but only one can benefit from the £10 million Longitude Prize Fund.'
0:57:02 > 0:57:06We want to get the whole country involved in deciding
0:57:06 > 0:57:11which of these challenges the £10 million prize fund should be
0:57:11 > 0:57:14offered for, and in just a few moments,
0:57:14 > 0:57:16when this programme finishes,
0:57:16 > 0:57:19you can cast your vote by text or online.
0:57:55 > 0:57:58'Texts will be charged at your standard rate.
0:57:58 > 0:58:04'Or you can vote for free online at bbc.co.uk/horizon.
0:58:04 > 0:58:06'There you'll find Terms and Conditions
0:58:06 > 0:58:09'and lots more information on the challenges too.
0:58:12 > 0:58:17'Voting will close at 7.10pm on the 25th of June with the result
0:58:17 > 0:58:19'announced live on The One Show that night.'
0:58:22 > 0:58:24It may take several years
0:58:24 > 0:58:27but eventually someone somewhere will come up with
0:58:27 > 0:58:31an effective solution to the challenge you choose,
0:58:31 > 0:58:35and a genuine claim to the new Longitude Prize.
0:58:35 > 0:58:40300 years ago, that someone was a clockmaker from Yorkshire.
0:58:40 > 0:58:42This time, could it be you?