Science series. Dallas investigates a potential helium shortage, Dr Yan tests shoppers on how much they know about radiation, and Liz tries out new airport security technology.
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Tonight Dallas investigates a global helium crisis and discovers why we should care.
Running out of helium would be really bad news.
It has a special property - the lowest boiling point of any known substance in the universe.
Liz tries out a new, controversial airport security device
that can see beneath your clothes.
I am concealing a non-metallic weapon on my person right now that neither detector picked up.
That's Bang Goes The Theory.
Hello and welcome to tonight's show. Thank you very much for joining us.
Now if I were to tell you that helium was running out, you might think, "So what?"
Fewer party balloons, no more squeaky voices, but there's more to helium than that.
It's vital for a whole host of hi-tech industries that would really struggle without it.
These days, we're really used to hearing about natural resources running out - oil, coal,
rain forest, minerals, tigers. That sort of thing. But did you know helium is a valuable resource, too,
with finite reserves that are quickly running out.
I don't know about you, but I've never thought about what happens to the helium inside my balloon
when I let it go. Maybe I should.
'Because what goes up doesn't always come down.
'Although the skin of a balloon will eventually drop back to Earth, the helium inside won't.'
The helium will continue up to the top of the atmosphere and eventually diffuse off into space.
'Now that is a problem because you can't make new helium.
'So once we've lost all the naturally available stuff, there simply won't be any left.
'I'm on a helium mission and it's brought me to Texas and the legendary town of Amarillo.'
Tony Christie was right. Even with the sat nav, I cannot find the way to Amarillo.
-SAT NAV: 'Drive 300 feet then turn right.'
-That's the way to Amarillo!
'Amarillo holds the status of being the helium capital of the world,
'a fact that Tony Christie fails to mention.'
Running out of helium would be really bad news,
not just for putting a dampener on kids' parties. Helium has another really important use
because it has a very special property - the lowest boiling point
of any known substance in the entire universe.
In liquid form, its temperature drops to minus 269 degrees Celsius.
That's only four degrees above absolute zero.
'That makes it perfect for creating super-conducting electromagnets,
'which are crucial components for medical MRI scanners.
'In fact, almost a third of the helium sold every year is for use in MRI and other instruments.'
Basically, without it we're going to be really stuck
and if the current global demand continues, we could be facing a shortage in the next 40 years.
'That's strange because it's the second most common element after hydrogen.
'A quarter of the mass of the entire universe is helium. Most was formed by nuclear fusion
'moments after the Big Bang.'
It is still being created up there, wherever nuclear fusion goes on.
That is the process that drives the stars, that drives our Sun,
where you have hydrogen atoms being mashed together to create brand-new helium atoms, but unfortunately,
that process is really difficult to recreate here on Earth.
'And that is what brings me here to a place that has more helium than anywhere else on the planet.'
-Hi, there. It's Dallas Campbell.
-'Come on in.'
'For such a precious resource, I'm surprised it isn't more heavily guarded.
'Apparently, the helium is through here.'
A kilometre or so beneath my feet is a gargantuan helium reservoir
that stretches out pretty much as far as the eye can see.
The helium's made by the radioactive decay of heavy metals in the rock,
which means, apart from anything else, it forms very, very slowly.
Over millions of years, the gas actually collects in subterranean pockets or reservoirs.
It's easy to imagine, when you say reservoirs, huge cavernous spaces underground,
but all we're talking about is areas of porous rock.
I've got some core samples here taken thousands of feet underground. You can see the porous rock here,
these tiny little holes, which are perfect for collecting helium or any other gas.
'Helium naturally forms alongside methane, the natural gas we burn for cooking and heating.
'In most gas fields, only a tiny fraction is helium and it's hardly worth extracting,
'but in the 1950s, US miners found levels as high as 7%.
'There had never been much use for the stuff before, but the arrival of the space race changed that.'
Helium was very important in developing the atom bomb
and in the early days of our defence systems and in the space race.
They felt it was all being wasted, so they developed a programme to extract the helium in Kansas,
Oklahoma and the Texas panhandle right here, and inject it into the ground right here.
It sounds really odd that you can actually use solid rock as a storage tank.
-You take helium from elsewhere and pump it into the ground here.
-That was the original purpose.
'By the time the Cold War was over, there was a worldwide demand for helium in scientific research.
'Maintaining this huge reservoir was expensive, so America began to sell it off at a rock bottom price.'
We produce about one-third of the world's helium supplies from here.
-That's not just America - that's from right here?
-From that point in the background.
'Now the flow of helium is reversed. Instead of pumping it into the ground through this valve,
'they open the tap and sell it to us.' In theory, could I stick a balloon at the end...?
In theory, but it would pop very quickly.
'While the scientific community carefully accounts for every bit of helium used and tries to recycle it,
'16% of the world's helium is still used in party balloons and airships.
-'They can hardly supply it fast enough.'
-It goes through this. It's 350 miles long.
It goes all the way up to Kansas.
'So at current rates there's about 10 years' worth of helium stored here.
'After that, there's only the tiny traces found in natural gas fields.
'That will be much more expensive to extract and eventually it's going to run out.'
It just feels bonkers to think that here I am standing in Amarillo on one third
of the entire world's helium supply,
but things like MRI scanners, cryogenics and high technologies rely on helium so much
it's a really, really important resource.
If we run out of helium there, how are these machines which rely on helium going to function?
That's really the nub of the matter. MRI is so much part of our lives.
Once the helium we've got stored is used up, a bit like oil,
eventually it will become really difficult to extract, the price goes up and we're in real trouble.
Can we not make a lot of helium ourselves in some way? Surely?
-Only through nuclear reactions. You can either squeeze hydrogen atoms together...
..to make helium, and that's nuclear fusion, or you can make it through fission,
the radioactive decay of larger elements, but we can't make much.
-Ergo, it's very difficult, then.
-My advice, next kids' birthday party, book a magician.
Nonetheless, we have some balloons here. Not helium balloons.
These two are inflated to markedly different sizes, connected by a pipe with a peg.
If I remove that peg to allow gas to flow freely between the balloons,
what happens to their sizes?
Like many of Dr Yan's brain teasers, think outside the box a bit. This is a good one.
-Don't give the answer away.
-Think about it,
then go onto the website where Dr Yan has all the answers.
While we're talking about helium and elements, the Open University have put up an all-singing, all-dancing
-interactive Periodic Table for your delight and delectation. All the details are at /bang.
Let's get back to Dr Yan and his adventures in science.
This is something I'm interested in - radiation. That word strikes fear in most of us,
so Dr Yan is testing our perception and knowledge of that word with some of the public.
Thank you for coming along.
I've got a couple of things from my high street shops and round about. Nothing unusual.
There are things here that are radioactive. What I'd like you to do
is put all the stuff you think is radioactive here
and all the stuff that isn't over there.
-An alarm clock?
-Radioactive because it's luminous.
I'd say no.
-The glow in the dark bit is.
-Brazil nuts. Anyone think Brazil buts are radioactive?
-We'll put them here, then.
-A lump of granite?
-It's a little radioactive.
-Radioactive! Is it not?
-I'd have said not.
-Antique glass bowl?
-Er...I'd say it is. What do you think?
-What do you think?
-How about a smoke alarm?
It is, but I don't know why.
-That's probably radioactive.
-You think that one is?
Brilliant. OK, thank you.
So you've got some of those things right, some not.
I can show you. Here I've got what is called a Geiger counter.
This measures ionising radiation, high energy radiation.
First, this isn't radioactive.
Lots of people think that the luminous paint on the clock makes it radioactive.
And it used to be the case that they used radium, but nowadays they don't.
So that goes right down there.
And the Brazil nuts. You sometimes hear it said they're radioactive.
That's because the tree has quite a big root network and takes up minerals.
The ones from Brazil are often more radioactive
because it has a little bit more uranium in the ground.
But these aren't from Brazil, so they're not! I can show you.
You can see it's sort of between one and two per second,
but it's not the uranium in this case. It's because all living things, like you and me, plants,
contain potassium and potassium naturally has a very small amount of radioactivity.
OK? So next...
This salt here is low sodium salt
and they replace some of the sodium with potassium in that low salt.
And so this...is somewhere between 5 and 10 per second.
Now how about the other stuff? Well, this bowl here is made out of uranium glass. Glass with uranium!
It's not got very much uranium in, but...
So next up is the smoke detector. Inside it is a little pellet of something called americium.
It's an element. And... it's quite radioactive.
Between 200 and 500 counts per second. But it's giving out a type of radiation
that doesn't even go through sheets of paper. It's fine.
Last of all, at the top - granite. People think that's radioactive.
And you're right. It's got uranium in it. 500 counts a second?
-You get lots of this in the UK, in Cornwall and places.
-That's where I live! Aaah!
I've got another little treat for you. Down here...
I've got a tub of nuclear waste.
You're only telling us now?!
-Where do you think this would lie?
-It's going to be there.
-Way over there.
Actually, it's slightly more radioactive than low-sodium salt.
I'll come clean, actually. This doesn't have radioactive waste.
I wasn't allowed to bring it out. It's a photo of myself with it.
You can see about 10 counts per second. A bit more than the salt.
That's about typical for low-level nuclear waste.
But if it was high-level radioactive waste, like spent fuel rods from inside a reactor,
then it would be maybe over a million million counts.
So right over there, way off the scale.
The interesting thing is it's a human psychology thing.
-When people hear the click of a Geiger counter, they react as if their days are numbered.
It's important to understand that radiation is all around us
and background radiation doesn't do us that much harm. In fact, we've evolved to deal with it.
Here's a really good little factoid.
10% of the radiation we're exposed to actually comes from inside our bodies.
-If I put it against me... you should be able to hear...
Don't confuse the viewers! I'm radioactive.
You must distinguish between what's dangerous or not.
You can kind of understand the misunderstanding.
Radiation is this sort of invisible, rather mysterious force.
So next week we've decided to dedicate the whole show to radiation and nuclear power.
It'll be really interesting. We've had such an amazing trip making that programme. Tune in.
Our dear Dr Yan, he is going to be a judge on a new BBC project
to find budding amateur scientists.
You don't have to be an Einstein to have a light bulb moment.
Anyone anywhere can have a hunch that's worthy of investigation.
This is where you'll get the chance.
It's called So You Want To Be A Scientist. If you have a question you want to research, get in touch.
All the details are on the website with an interview with Ruth Brooks, last year's winner.
But you've only got until 31st October.
For a bit of inspiration, we've got genius British ideas
that have made it past the research stage. I'm loving this one - this can actually help save lives.
This is a portable water quality tester. It's been trialled by the University of Birmingham
in places like remote villages in India and South Africa
where usually it can take a minimum of five days to get results of whether water is drinkable.
And it works like this. You put a little bit of water in this tube
and you sample it. This kit measures the amount of tryptophan in the water.
It's an amino acid that reflects how much organic matter is in the water.
You get an idea of the disease-causing bacteria, faecal matter. I think this is fantastic.
Very good indeed. A little bit less hi-tech, but I love it nonetheless
is concrete cloth.
It's a cloth impregnated with concrete. Imagine a disaster area.
You can inflate temporary buildings like they do with a bouncy castle,
cover it with the concrete cloth, spray it with water, leave it 24 hours and you get this -
-a rock-hard skin.
-That is amazing.
-All the applications for that - brilliant.
Let's stick with technology and talk about airport security making the headlines,
not because it's helping us in the war against terrorism, but because it sees through your clothes.
Great technology or an invasion of privacy? I went to find out.
'It may be an inconvenience, but these days airport security is part and parcel of checking in.
-'And it almost always begins with one of these.
'A metal detector. It's simple enough technology.
'A huge magnetic field detects anything metal passing through it,
'spotting anyone trying to hide a knife or a gun.'
Of course, metal detectors are great at detecting, well, metal.
Ah, my radio mic! Thanks.
But weapons are made of lots of different materials. I am presently concealing a non-metallic weapon
on my person right now that neither detector picked up.
Pat downs and full body searches are an option, but time-consuming.
The last thing you want is extra-long queues for flights.
What you need is something that can see through my clothes.
Of course, while you're going through the metal detector,
your luggage goes through an X-ray machine, which sees through things. How does it do it?
With cunningly planted objects - a bottle of shampoo, a hair drier and a see-through necklace -
I'll find out.
So my suitcase is going through the X-ray machine. What is going on in there right now?
As the bag has gone into the X-ray tunnel, we've fired X-ray energy at the bag,
which has gone through the bag.
As it goes through, it is absorbed at different rates by different pieces of material it contacts.
So the energy that goes in is different to the energy coming out and we can make a picture.
What do the different colours mean?
Orange depicts something that is positively organic. That means something definitely not metallic.
So most items fall into the organic range. Blue, as you can see here,
-is something positively metallic.
If it's not sure or it's an equal combination, it's green.
-What are you seeing here, then?
You've got a bottle here which looks way outside the legal limit to board an aircraft.
Yes, it's over 100ml. It's my shampoo.
-What about over here? What's going on?
-We've got a metallic case because it's blue,
-but what appears to be, to me, a necklace.
-Why is it black, then?
Items that are very dense - lead for example or large lumps of metal - they're black.
It is possible it's polished metal beads or it could be lead crystal.
'High-energy X-rays reveal what's inside your luggage because they pass through some materials
'more easily than others, but they're not an option for scanning passengers.
'As well as going through your clothes, high-energy X-rays will go through your body
'and can cause harm. Repeated exposure is very dangerous, so we cannot risk X-raying every passenger
'on every flight. But X-rays aren't the only option.
'They're just one part of a whole family of electro-magnetic waves.
'And with the help of some hosepipe at the airport fire station,
'I'm going to show you some of the others.'
Electro-magnetic radiation can be described as energy that travels in waves through space.
There's lots of different types of radiation depending on its wavelength and frequency.
The entire range of radiation can be described in the electro-magnetic spectrum.
'X-rays are among the smallest, just above the tiny gamma waves.'
Wavelengths here can be as small as one picometre in length.
The thickness of one strand of my hair is 50 million picometres, so that's very short wavelengths.
'Almost a million times bigger, light waves are still under a thousandth of a millimetre.
'Microwaves can be a whole centimetre. Then, finally, there are radio waves,
'which can be tens or even hundreds of metres long.
'Each of these waves can pass through different materials.
'What we need at the airport is something that uses a wave that gets through clothes, but not bodies.
'And here it is. The millimetre wave scanner.'
The good thing about this energy level is it's not absorbed by the body, so it's very safe to use.
It will go through your clothes. Your body is much more dense, so it will reflect the vast majority
back to the scanner. We then measure that millimetric wave radiation and turn it into a picture
to look at the contours of your body for anything concealed.
OK, let's do it before I lose my bottle and run off.
-I'm going to walk over here. Stand on that circle.
-'So will it spot this hidden weapon of mine?
'Or, come to think of it, anything else under my clothes?'
-And stop there.
-OK. I forgot to suck in my belly!
-It'll be fine.
-OK, here's the image of your entire body.
-But have you found my weapon?
-I think so.
-Have you? Go on.
-If we turn it round, I believe you have a knife
-placed on the small of your back, but between your bra.
It is actually a knife. A ceramic knife, stuck into my bra strap. Awesome.
-And the radiation found it.
-It really did. Excellent stuff.
'With a new generation of scanners rolling out at airports across the UK,
'checking in has never been safer or quicker.'
It's an amazing bit of tech, but it does raise privacy questions.
-There will be people at home watching that thinking, "I am not walking through that."
It is understandable, but for those scanners, the operators of the visual part of the scanner
are nowhere near the scanner. They never see the individual go through.
They're always same sex operators. A woman operator looks at women.
The images are never recorded and also because the whole scanning technology is based on contours,
your underwear is so close to your body that it helps conceal the more detailed bits of your anatomy.
Your bits and bobs. Fair enough, but still people will worry. Is it going to be compulsory?
So far, these haven't rolled out across the UK and the guidelines aren't set in stone.
Ultimately, it's going to be down to each airport to decide.
Something I was a bit more curious about is the safe exposure limits.
Say, for example, I was a frequent flyer going through these things five, ten times a week.
-Is that too much?
-I fly a lot for my job and had the same question.
These scanners have been rigorously tested and the results are they don't cause you any harm.
-The operators can stand beside it 24/7 and the health risks are negligible.
-There you go.
We've come to the end of the show. In two weeks' we're in Manchester doing Bang Live.
We'd love it if you came to see us. All the details are at /bang.
And you can catch up on one of our favourite projects from the past.
Remember my coffee-powered car?
4.30am. Time to wake up and smell the coffee.
But I'm not drinking it. I'm converting it into flammable gas
that hopefully will get this car 210 miles from BBC Television Centre to Manchester.
It couldn't have started any better and then gone any worse.
The car overheats, then we have to pull it onto a truck, then we can't start it again.
We have a problem with gas quality. We're supposed to be in Manchester, we're not even in Birmingham.
That was absolutely amazing!
Well, since that epic journey to Manchester,
somebody's taken the idea and seriously pimped it up.
And just a few days ago, Coffee Car Mark 2 made an attempt on a new land speed record.
True to form, not everything went to plan.
# Raindrops are falling on my head
# But that doesn't mean my eyes will soon be turning red
# Crying's not for me... #
You can see how it all turned out and get the full story on /bang.
# Because I'm free... #
Indeed. As we mentioned earlier, next week is a bit special.
We're going to look at nuclear power, at radiation - what it is and why it's so controversial.
-We'll see you then. Bye bye.
Subtitles by Subtext for Red Bee Media Ltd - 2011
Email [email protected]
Dallas investigates a potential global helium shortage, Dr Yan tests shoppers on how much they know about radiation, and Liz tries out the new airport security technology that can see beneath your clothes.