Category Archives: Research

Where’s that huge iceberg headed?

Corrinne Burns blogs on ADIOS, a GPS enabled javelin which helps tracks icebergs. You can see ADIOS on display in the Museum’s contemporary science gallery.    

Why would you put a GPS tracker onto a glacier? These positioning devices are more commonly associated with cars. It’s not like glaciers are in any danger of getting lost – or of ending up in a field of bemused cows, for that matter.

Actually, there’s good reason why scientists track the movement of ice. The Antarctic Ice Sheet is the biggest unknown when it comes to predicting sea level change.

An iceberg breaking away. Credit: NASA

An iceberg breaking away. Credit: NASA

Glaciers move – we all know that. It’s natural. But as the ocean temperature rises, glaciers move at an increased rate. That’s because melting, triggered by the warming sea, causes the ice streams within the glacier to flow faster and faster.

And of course, as glaciers melt, the global sea level rises.

So this “flow velocity”, as glaciologists call is, can be used as a way to track rising sea levels. That’s why it’s so important to track the movement of glacial ice streams.

Hilmar Gudmundsson works at the British Antarctic Survey, keeping an eye on ice dynamics. He’s been putting GPS trackers onto glaciers for a while now. Traditionally, a helicopter lands a crew onto the glacial surface, and then they walk across the frostbitten landscape, implanting trackers as they go.

But Hilmar knows how dangerous walking on ice can be – deep crevasses await the unwary. So he helped to invent a rather unusual way to deploy such trackers, so that no human need even set foot on the ice.

The solution was ADIOS – the Aircraft-Deployable Ice Observation System. ADIOS is, essentially, a GPS tracker embedded within a 2.5-metre long javelin, designed to be dropped from an aircraft flying a few hundred metres above the ice. One such ADIOS device is currently on display in the Museum’s Antenna gallery.

ADIOS – the Aircraft-Deployable Ice Observation System. Credit: British Antarctic Survey

ADIOS – the Aircraft-Deployable Ice Observation System. Credit: British Antarctic Survey

ADIOS takes inspiration from technology originating from World War Two – the sonobuoy. These were floating sonar transducers, deployed by aircraft into the ocean to listen out for warships. Hilmar and colleagues adapted this wartime concept for the 21st century Antarctic – but glaciers do present some challenges that water does not.

For one, the electronics needed to survive the impact on hard ice – a polyethylene cushion and a spring help to protect them from impact forces of up to 1200G, and a parachute slows and stabilises ADIOS’ descent. You also need to consider the effects of snowfall – anything placed on the surface is likely to be covered in snowdrifts pretty quickly.

Those considerations led to the long, aerodynamic javelin-like design.

The GPS tracker itself is positioned towards the sharp nosecone-end of ADIOS, and, after landing, sits below the surface of the ice. It transmits through an antenna situated at the opposite end of the javelin – which, thanks to four “snow brakes”, remains above the snow surface. It is so long that it can remain uncovered even following thick snowfall, transmitting for up to two years.

Hilmar’s interested in part of Antarctica called the Pine Island Glacier, or PIG. His team deployed 37 ADIOS sensors onto the glacier in January of last year. PIG is significant because of all the icy regions on Earth, this glacier is showing the biggest changes in ice movement and thickness, so we need to keep an eye on it. “We can already see that the rate of ice flow is increasing, since we deployed those units,” says Hilmar.

Even more dramatically, a few months ago a 700 square km bit of PIG broke off, forming a massive rogue iceberg that is now further fragmenting and drifting towards shipping lanes. Two ADIOS’ sit on that rogue berg – not by coincidence. “We knew that this ice was breaking away from PIG – that’s why we put two ADIOS units on it,” says Hilmar. As the rogue iceberg has broken apart further, those units now sit on two different fragments – and are still sending back live data about position.

So, as well as telling us about glacial melt, ADIOS units can be used to track the movements of icebergs heading for shipping lanes. Will we see more air-deployed GPS trackers on icebergs around the world, then? “This is now tried-and-tested technology. There’s a lot of interested from other researchers, and we’ll let them use the design,” says Hilmar. “And for me – I’m relieved that it works!”

You can find out more about ADIOS, in the Science Museum’s contemporary science gallery from now until April 10, 2014. 

The Echo of Creation – Astronomers Hear the B of the Big Bang

Dr. Harry Cliff, Curator of our Collider exhibition and the first Science Museum Fellow of Modern Science explores one of the most important discoveries of a generation.

In what has been hailed as one of the most important discoveries of a generation, astronomers working on the BICEP2 telescope at the South Pole have announced that they have detected gravitational tremors from the birth of our Universe imprinted across the sky. The result is the first direct evidence for inflation, the theory that the Universe expanded unimaginably fast, an infinitesimal instant after time zero.

The BICEP2 telescope at the Amundsen-Scott South Pole station.

The BICEP2 telescope at the Amundsen-Scott South Pole station. Credit: BICEP2

The theory of inflation states that the Universe grew in volume by about a factor of at least 1078, a number so vast that it’s impossible to comprehend (its roughly equal to the number of atoms in the universe). This phenomenal expansion took place in an incredibly short time, in about ten billionths of a trillionth of a trillionth of a second, at a time when the Universe was cold, dark and empty. To put this in context, if the full stop at the end of this sentence were to grow by the same factor, it would end up about a hundred times larger than our galaxy.

Inflation is a crucial part of modern cosmological theories and solves many serious problems with the traditional Big Bang model, but so far there has been no direct evidence that it actually happened. However, inflationary theories predict that this violent expansion would have created ripples in space and time known as gravitational waves. These ripples would then have echoed through the cosmos, leaving a mark on the oldest light in the Universe, the Cosmic Microwave Background (CMB).

Discovered fifty years ago by the American radio astronomers Arno Penzias and Robert Wilson (who at first mistook it for pigeon poo in their receiver), the CMB is the remnant of the light emitted 380,000 years after the Big Bang, when the Universe cooled enough for atoms to form and for light to travel freely across space. The discovery of the CMB was one of the most important events in the history of science, providing convincing evidence that the Universe began in a violent hot expansion known as the Big Bang. This ancient light has been stretched from a searing hot 3000 Kelvin to a freezing 2.7 Kelvin by the expansion of space, leaving it as a faint microwave signal coming from the entire sky.

The BICEP2 telescope is based at the Amundsen-Scott station at the geographic South Pole, where temperatures plummet to below minus 70 degrees Celsius in the Antarctic winter and the base is buffeted by blizzards and gale force winds. Despite these incredibly hostile conditions, the BICEP2 telescope is in the perfect location to study the CMB.

The South Pole is around 3000 metres above sea level, and the driest place on Earth, meaning that there is relatively little atmospheric water vapour that would otherwise screen out the CMB signal. This comes with the added advantage that BICEP2 is able to scan the same small piece of sky all year round, by effectively looking straight down from the bottom of the planet to the point known as the celestial south pole.

BICEP2 astronomers spent almost three years scanning the CMB in incredible detail, but yesterday the freezing conditions and hard work paid off spectacularly as they revealed subtle twists in the CMB, a smoking gun for gravitational waves from inflation. In fact, the BICEP2 astronomers were surprised by just how strong the signal was. “This has been like looking for a needle in a haystack, but instead we found a crowbar,” said co-leader Clem Pryke.

Twists in the cosmic microwave background that provide evidence for inflation

Twists in the cosmic microwave background that provide evidence for inflation. Credit BICEP2

Although the result hasn’t been peer reviewed or published in a scientific journal yet, most astronomers agree that the findings look solid. The fifty-strong BICEP2 team have been sitting on their historic result since the end of 2012, and have spent more than a year checking and rechecking to ensure they have taken account of every possible effect, from gravitational lensing to space dust, which might have given a false result.

So what does this mean for our understanding of our Universe? The BICEP2 result is really three Nobel Prize-worthy discoveries in one. They have found the first convincing evidence that inflation really happened, giving science its first glimpse of the moment in which the universe came into being. Second, they have found the strongest evidence yet for gravitational waves, the last prediction of Einstein’s theory of general relativity to be verified, and something that astronomers have been searching for for decades. Third, and by no means least, this discovery demonstrates a deep connection between quantum mechanics and gravity, giving hope that we may one day find evidence of a theory of everything, a theory that would unite our theory of particles and forces with our theory of cosmology and gravity. This would undoubtedly be the greatest prize in science.

If confirmed by other observatories, this incredible result will go down in history as one of the most important scientific discoveries of the 21st century, eclipsing even CERN’s discovery of the Higgs boson in 2012. Nobel Prizes will almost certainly follow. More importantly, this result opens up a new window through which astronomers and cosmologists may, for the first time, glimpse the very moment of creation.

Explore more about astronomy in our Cosmos and Culture gallery and discover the mysteries of deep space in our Hidden Universe 3D IMAX film.

From Earth to space in a Skinsuit

Julia Attias, a Research Assistant working at the Centre of Human and Aerospace Physiological Sciences (CHAPS), talks about her career in space science for our Beyond Earth festival this weekend. 

My name is Julia Attias and I’m a space physiologist. What does that mean? “Physiology” generally refers to the functions and processes of the human body. Space physiology involves the understanding of how the body functions in space, and particularly in an environment that has far less gravity than on Earth. It’s important to know how low gravity environments affect people taking part in space missions.

I became a space physiologist through completing a Masters degree in Space Physiology and Health at Kings College London in September 2012. The course is designed to help us understand the challenges that an astronaut’s body faces both in space and on return to Earth, such as muscle and bone loss, weakening of the cardiovascular system and visual disturbances.

During my masters dissertation, I started to research the “Gravity-Loading Countermeasure Skinsuit” (GLCS), funded by the European Space Agency (ESA). The Skinsuit was designed by a group of aerospace engineers at MIT, with the aim to recreate the same force that the body experiences through Earth’s natural gravitational pull. This way, if the Skinsuit is worn in environments of zero-gravity, the body should be protected from some of the issues mentioned above.

Testing the Skinsuit

Testing the Skinsuit

I’ve been studying the Skinsuit to see if it really does produce a gravity load similar to Earth’s, and if it could be used in the future alongside exercise activities to keep astronauts fit and keep their heart, muscles and bones strong in space.

Space travel is becoming of increasing interest in the UK, primarily owing to British astronaut Tim Peake, who will be flying to the International Space Station in 2015! During the next year, there will be many discussions about how to keep him healthy while in space.

I’ll be starting a PhD in October 2014 which will involve continuing my research with the Skinsuit to see how it might help tackle issues such as back pain and spinal elongation. This research will combine with other work conducted all over the globe to help keep astronauts like Tim Peake as free of physiological burden as possible for their return to Earth.

Unfortunately I won’t be at the Beyond Earth festival this weekend, because I’ll be testing the Skinsuit with ESA astronaut Thomas Pesquet!  We’ll be testing the Skinsuit in a weightless environment (not in space unfortunately!) through a parabolic flight. We will get into an aircraft which descends rapidly, creating up to 22 seconds of weightlessness at a time – it’s a bit like being on a roller coaster. The flight is to test the Skinsuit in a weightless environment – taking off and putting on the suit to ensure the simple things we take for granted on Earth are possible in zero-gravity!

Information Age: Testing, testing, 1 2 3

Jack Gelsthorpe and Lauren Souter are both Audience Researchers working on the new Information Age gallery. Here they discuss some of the work they do in prototyping digital media for the exhibition.

In September 2014 an exciting new gallery, Information Age, which celebrates the history of information and communication technologies, is due to open at the Science Museum.

The gallery will include some truly fascinating objects such as the 2LO transmitter, part of the Enfield telephone Exchange and the impressive Rugby Tuning Coil. As well as these large scale objects, the exhibition will house smaller objects such as a Baudot Keyboard, a Crystal Radio Set, and a Morse Tapper.

Information Age will also contain a host of digital technology and interactive displays where visitors will be able to explore the stories behind the objects and the themes of the exhibition in more detail.

This is where we come in.

As Audience Researchers, it is our job to make sure that visitors can use and engage with the digital displays in this gallery whilst also ensuring that they don’t draw attention away from the objects and the stories they tell.

We do this by testing prototypes of the interactive exhibits, games, web resources and apps with visitors both in the museum and through focus groups. There are three stages in the prototyping process. We begin by showing people a ‘mock up’ of a resource so that we can get feedback on our initial ideas. This can be very basic, for example we have been testing for Information Age with storyboards on paper, handmade models (which have sometimes fallen apart during the testing process!) and computers.

A prototype of an interactive model that represents the Baudot Keyboard

A prototype of an interactive model that represents the Baudot Keyboard

We invite visitors to try these prototypes while we observe and make notes and then we interview them afterwards. This helps us to understand what people think about our ideas, whether people find the resources usable and whether the stories we want to tell are being conveyed effectively. We then discuss our findings with the Exhibition team who are then able to further develop their ideas. The resources are tested a second and third time using the same process to ensure that the final experience is interesting, fun and engaging.

As well as testing these resources in a special prototyping room we also test some of the experiences in the museum galleries to see how visitors react to them in a more realistic setting.

Recently we have been prototyping electro-mechanical interactive models of some of the smaller objects that will be on display in Information Age. These exhibits intend to give visitors an insight into what it would have been like to use these objects whilst explaining the scientific processes behind how they work.

A prototype of an interactive model that represents the Double Needle Telegraph.

A prototype of an interactive model that represents the Double Needle Telegraph.

We will be testing different digital experiences until September, so you may see us in the prototyping room or the galleries. If you see us feel free to say hello and ask us any questions.

Experience these interactive models for yourself in the new Information Age gallery, opening Autumn 2014.

Peter Higgs: The Life Scientific

Quantum physicist and broadcaster Jim Al-Khalili blogs on interviewing Peter Higgs for the new series of The Life Scientific on BBC Radio 4. Discover more about the LHC, particle physics and the search for the Higgs boson in our Collider exhibition

I love name dropping about some of the science superstars I’ve interviewed on The Life Scientific. ”Richard Dawkins was quite charming on the programme, you know”, or “James Lovelock is as sharp as ever”, and so on. So imagine my excitement when I heard I would be interviewing the ultimate science celebrity Peter Higgs.

When I discovered we had secured him for the first programme in the new 2014 series, I knew I had to get something more out of him than to simply regurgitate the popular account of the man as shy, modest and unassuming, and still awkward about having a fundamental particle named after him; or how the Nobel committee were unable to get hold of him on the day of the announcement because he had obliviously wandered off to have lunch with friends.

This was an opportunity for two theoretical physicists – OK, one who has a Nobel Prize to his name and one who doesn’t, but let’s not split hairs here – to chat about the thrill of discovery and to peek into the workings of nature, whilst the outside world listened in.

A couple of Bosons: Peter Higgs with Jim Al-Khalili

A couple of Bosons: Peter Higgs with Jim Al-Khalili. Credit: Charlie Chan

You can listen to the programme from 18 February, but here are a few extracts to whet your appetite.

Can you explain the Higgs mechanism in 30 seconds?

At some point in the programme, inevitably, I had to ask Peter to explain the Higgs mechanism and Higgs field (both more fundamental concepts than the Higgs boson). He gave a beautifully articulate and clear explanation, but I then thought I should ask him to give the ‘idiot’s guide to the Higgs’, just to cover all bases. Here’s how that went:

‘The Boson that Bears my Name’

Working alone in Edinburgh in the sixties, Peter Higgs was considered ‘a bit of a crank’. “No-one wanted to work with me”, he says. In 1964, he predicted the possible existence of a new kind of boson, but at the time there was little interest in this now much-celebrated insight. And in the years that followed, Peter Higgs himself failed to realise the full significance of his theory, which would later transform particle physics.

In July 2012, scientists at the Large Hadron Collider at CERN confirmed that the Higgs boson had indeed been found and Peter Higgs shot to fame. This ephemeral speck of elusive energy is now the subject of car adverts, countless jokes, museum exhibitions and even a song by Nick Cave called the Higgs Boson Blues. But Higgs has always called it the scalar boson or, jokingly, ‘the boson that bears my name’ and remains genuinely embarrassed that it is named after him alone.

In fact, three different research groups, working independently, published very similar papers in 1964 describing what’s now known as the Higgs mechanism. And Higgs told me he’s surprised that another British physicist, Tom Kibble from Imperial College, London didn’t share the 2013 Nobel Prize for Physics, along with him and Belgian physicist, Francois Englert.

On fame
When the 2013 Nobel Prize winners were announced, Peter was famously elusive (much to the frustration of the world’s media). Most people romanticised that he was blissfully unaware of all the fuss or just not that interested. These days, he’s constantly being stopped in the street and asked for autographs, so I asked him whether he enjoyed being famous:

Physics post-Higgs
With the discovery of the Higgs finally ticked off our to-do list, attention is turning to the next challenge: to find a new family of particles predicted by our current front-runner theory, called supersymmetry. Higgs would ‘like this theory to be right’ because it is the only way theorists have at the moment of incorporating the force of gravity into the grand scheme of things.

But what if the Large Hadron Collider doesn’t reveal any new particles? Will we have to build an even bigger machine that smashes subatomic particles together with ever-greater energy? In fact, Peter Higgs believes that the next big breakthrough may well come from a different direction altogether, for example by studying the behaviour of neutrinos, the elusive particles believed the be the most common in the Universe, which, as Higgs admits, “is not the sort of thing the Large Hadron Collider is good for”.

When it started up in 2008, physicists would not have dreamt of asking for anything bigger than the Large Hadron Colider. But today one hears serious talk of designing a machine that might one day succeed it. One candidate is the somewhat unimaginatively named Very Large Hadron Collider. Such a machine would dwarf the Large Hadron Collider. It would collide protons at seven times higher energy than the maximum the Large Hadron Collider is able to reach. And it would require a tunnel 100 km in circumference. Of course this is not the only proposal on the table and there are plenty of other ideas floating about – none of which come cheap, naturally.

There are certainly plenty more deep mysteries to solve, from the nature of dark matter and dark energy to where all the antimatter has gone, and we will undoubtedly find the answers (oh, the delicious arrogance of science). Let’s just hope we don’t have to wait as long as Peter Higgs did.

Keen to discover more? You can listen to Peter Higgs on BBC Radio 4′s The Life Scientific (first broadcast 9am on 18 February) and visit the Collider exhibition at the Science Museum until 5 May 2014. 

10 Bonkers Things About the World

We asked author and journalist Marcus Chown, who is speaking at this month’s Lates, to share his favourite science facts.

I’ve just published a book about how the world of the 21st century works. It’s about everything from finance to thermodynamics, sex to special relativity, human evolution to holography. As I was writing it, I began to appreciate what an amazing world we live in – more incredible than anything we could possibly have invented – which is why I called my book What A Wonderful World. What better way to illustrate this than to list my Top 10 Bonkers Things About the World.

1. The crucial advantage humans had over Neanderthals was sewing

Human needles made from bone have been unearthed but never a Neanderthal needle. This has led to the speculation that the ability to sew baby clothes may have given human babies a crucial survival advantage during the cruel Ice Age winters.

2. You could fit the entire human race in the volume of a sugar cube

Sugar Cubes

Credit: Flickr/KJGarbutt

This is because atoms are 99.9999999999999% empty space. If you could squeeze all the empty space out of all the atoms in all the 7 billion people in the world, you could indeed fit them in the volume of a sugar cube.

3. Slime moulds have 13 sexes

No one knows why. But, then, nobody is sure why there is sex. The best bet, however, is that it evolved to outsmart parasites. Parents, by shuffling together their genes, continually create novel offspring to which parasites are not adapted.

4. You age more quickly on the top floor of a building than the ground floor

This is an effect of Einstein’s theory of gravity, which predicts that time flows more slowly in strong gravity. On the ground floor of a building, you are closer to the mass of the Earth so gravity is marginally stronger and time flows marginally more slowly (If you want to live longer – move to a bungalow!)

5. J. J. Thomson got the Nobel prize for showing that an electron is a particle. His son got it for showing that it isn’t

JJ Thomson. Credit: Cavendish Laboratory

The ultimate building blocks of matter – atoms, electrons and so on – have a strange dual nature, behaving simultaneously like tiny, localised billiard balls and spread-out waves. The truth is they are neither particles nor waves but something for which we have no word in our vocabulary and no analogy in the familiar, everyday world.

6. You are 95% alien

Stacks of Petri Dishes with Bacterial Colonies.

Stacks of Petri Dishes with Bacterial Colonies. Credit: Science Faction/UIGH/SSPL

That’s right. 95% of the cells in your body do not belong to you. They are microorganisms hitching a ride. Many are essential like the gut bacteria that help you digest your food. You get all the alien microorganism only after you are born – from your mother’s milk and the environment. You are born 100% human but die 95% alien!

7.  Brains are so energy hungry most organisms on Earth do without them

Sections through the brain

Sections through the brain. Credit: Florilegius/SSPL

The best illustration of this comes from the juvenile sea squirt. It swims through the ocean looking for a rock to cling to and make its home. When it finds one, it no longer needs its brain so it… eats it!

8.  Babies are powered by rocket fuel

Atlas V Launches Inmarsat Communications Satellite. Credit: Science Faction/UIGH/SSPL

Atlas V Launches Inmarsat Communications Satellite. Credit: Science Faction/UIGH/SSPL

Rockets combine liquid oxygen with liquid hydrogen to make water. This liberates just about the most energy, pound for pound, of any common chemical reaction. Babies – and in fact all of us – do the same. We combine oxygen from the air with hydrogen stripped from our food. The energy liberated drives all the biological processes in our bodies.

9.  There was no improvement in the design of stone hand axes for 1.4 million years

A mesolithic hand axe, found in Saint Acheul, near Amiens, France. Credit: Science Museum / SSPL

A mesolithic hand axe, found in Saint Acheul, near Amiens, France. Credit: Science Museum / SSPL

Palaeoanthropologists call it the ‘1.4 million years of boredom’. It could be of course that our ancestors made tools from wood, which decayed, or from bone, which are impossible to distinguish from natural bones. And, just because tools did not change, does not mean nothing was happening. All kinds of things that left no record may have been going on such as the taming of fire and the invention of language.

10. 98% of the Universe is invisible

Earthrise over the moon, taken by the Apollo 8 crew, 24 Dec 1968.

Earthrise over the moon, taken by the Apollo 8 crew, 24 Dec 1968. Credit: NASA

Only 4 per cent of the mass of the Universe is made of atoms – the kind of stuff, you, me, the stars and planets are made of – and we have seen only half of that with our telescopes. 23% of the Universe is invisible, or “dark”, matter, whose existence we know of because it tugs with its gravity on the visible stuff. And 73% is dark energy, which is invisible, fills all of space and has repulsive gravity which is speeding up the expansion of the Universe. If you can find out what the dark matter or dark energy is, there is a Nobel prize waiting for you!

Find out more at this month’s Lates or in Marcus Chown’s book What A Wonderful World: One man’s attempt to explain the big stuff (Faber & Faber).

Obituary: Fred Sanger (1918 – 2013)

Director of External Affairs, Roger Highfield, remembers Nobel laureate Fred Sanger.

The biochemist and Nobel laureate Fred Sanger would joke that ‘I am all right at the thinking, but not much good at the talking.’ Despite his huge influence, Sanger also once said that: ‘I am not academically brilliant.’

Frederick Sanger. Credit: Wikipedia

Frederick Sanger. Credit: Wikipedia

I met him for the first time among the audience of a Wellcome press conference in London and, not once in our chat about human genomics, did he let slip who he was and the landmark contribution that he had made to the field.

In fact this modest man was one of the greatest innovators of all time with his emphasis on developing new techniques, notably DNA sequencing, the ability to read the genome, or genetic recipe, of an organism while working at the Medical Research Council’s Laboratory of Molecular Biology in Cambridge.

Ian Blatchford, Director of the Science Museum, commented on hearing news of his death that  Sanger was a ‘giant in genetics, who had an astonishing capacity to crack some of the most challenging problems in biology. His passing marks the end of an era in modern genetics.’

The American genome pioneer and synthetic biologist, Craig Venter of the J. Craig Venter Institute in Rockville and La Jolla, said on hearing the sad news: ‘Fred Sanger was one of the most important scientists of the 20th century. He twice changed the direction of the scientific world, first with the sequencing of insulin, proving that proteins were linear strings of amino acids and second with his then new method of sequencing DNA, which led to the field of genomics. His contributions will always be remembered.’

Most sequencing performed for the past decades is a direct extension of the methods that were pioneered by Fred Sanger. He unveiled his first partial DNA sequence in May 1975 and went on to deliver the first complete determination of the sequence of a DNA molecule: the 5375 ‘letters’ in the genome of a bacterial virus called phi-X174.

This machine, developed in 1987, uses the Sanger method for DNA sequencing. Credit: Science Museum

This machine, developed in 1987, uses the Sanger method for DNA sequencing. Credit: Science Museum

The DNA reading method that Sanger developed in Cambridge with Alan Coulson required the manufacture of lots of copies of the DNA molecule using an enzyme called DNA polymerase. For the polymerase to replicate DNA it needs DNA building blocks – molecules called nucleotides – which correspond to the four ‘letters’ of the genetic alphabet.

The enzyme reads from each end of the original molecule to make new copies. For sequencing, Sanger added another ingredient: molecules called ‘terminator nucleotides’, each radioactively-labelled, which are so named because they stop the polymerase when they are incorporated in the growing copy. As a consequence, the enzyme incorporates a terminator in the growing DNA chain, halting the process and marking the end of the growing chain with a radioactive molecule as a full stop.

Because this interruption occurs at any stage of the process of copying vast numbers of DNA molecules in the test tube, a mixture is produced of DNA fragments of varying lengths, each finishing with a radioactively-marked C, G, A or T, depending on which base had been labelled.

An electric field was used to drive these fragments through a gel to separate the DNA molecules according to their size and reveal the sequence: the largest pieces of DNA take more time to migrate through the gel. Because the radioactive label on all four terminators produces the same black mark on an X ray film, Sanger had to carry out four individual experiments, one for each different letter of the code, on four adjacent tracks on the same gel. When the genetic fragments separate, one track shows the DNA fragments that end with a C, one those that end with a G and so on.

Then Sanger and his colleagues studied the film, starting with the first band from the four letter tracks, moving to where the next closest band appeared. In this way, they could read the digital recipe of life. If the first, smallest, piece of DNA was in the C track, for example, then C was the first letter. If the next black mark was in the A track, then an A followed.

Sanger sequenced the 17,000 or so letters of DNA in the human mitochondrion, the energy factory found in our cells. This feat can be regarded the first human genome project. He won the Nobel prize for this work in 1980 but it was far from his first major award.

Frederick Sanger used this equipment to study the structure of insulin by electrophoresis in the 1950s. Credit: Science Museum

Fred Sanger used this equipment to study the structure of insulin by electrophoresis in the 1950s. Credit: Science Museum

He had been given his first Nobel prize in 1958, for his research on the structure of proteins, when he worked out the order of the 50 or so amino acids that make up the insulin molecule. This work revealed how DNA specified linear strings of amino acids in proteins, and that proteins were not agglomerations of closely-related substances, as many had thought in the first half of the 20th century, but were indeed a single chemical.

The world has lost a gene genius.

Discover more about genetics in the Science Museum’s Who Am I? gallery.

Beaming with Joy: LHC celebrates five years of not destroying the world

Content Developer Rupert Cole, and Science Museum Fellow of Modern Science Dr. Harry Cliff, celebrate the LHC’s 5th birthday for Collider, a new Science Museum exhibition opening in November 2013.

Five years ago, at breakfast time, the world waited anxiously for news from CERN, the European Organization for Nuclear Research. The first nervy bunch of protons were due to be fired around the European lab’s latest and biggest particle accelerator, the Large Hadron Collider (LHC), as it kicked into action.

Some “mercifully deluded people” – as Jeremy Paxman put it – feared the LHC would do no end of mischief. There was talk of planet-swallowing black holes, the transformation of the Earth into a new state of “strange” matter, and even the prospect of the obliteration of the entire universe. But for those of more sensible dispositions, the LHC’s first beam was an occasion for great excitement.

As the protons sped all the way round the 27km tunnel under the countryside between Lake Geneva and the Jura Mountains, thousands of physicists and engineers celebrated decades of hard work, incredible ingenuity and sheer ambition. Together they had created the largest-ever scientific experiment.

After the LHC was switched on, project leader Lyn Evans said, “We can now look forward to a new era of understanding about the origins and evolution of the universe.”

Operating a massive particle accelerator requires much more than flicking a switch – thousands of individual elements have to all come together, synchronised in time to less than a billionth of a second.

University College London’s physicist Jon Butterworth recalls a “particularly bizarre memory” from that day. Relaxing in a Westminster pub after an exhausting LHC event in London, Butterworth found he could follow live updates from his own ATLAS experiment on the pub’s TV.

Time for a rest. Credit: CERN

Particle physics continued to make news. The following fortnight’s joy turned to dismay as an accident involving six tonnes of liquid helium erupting violently in the tunnel – euphemistically referred to as “the incident” – damaged around half a mile of the collider, closing the LHC for a year.

Since then, besides the brief setback that was “baguette-gate”, a bizarre episode when the collider was sabotaged by a baguette-wielding bird, the LHC has been producing great work. Hundreds of scientific papers have been published by the CERN experiments, on topics as diverse as searches for dark matter candidates, the production of the primordial state of matter (known as quark-gluon plasma) and precision measurements of matter-antimatter asymmetries.

However, it was on July 4 last year, that the LHC snared its first major catch with the discovery of the Higgs boson – as one of the most significant scientific finds of the century. The Higgs boson was one of the longest-sought prizes in science – it was almost fifty years ago in 1964 that three groups of theorists laid the ground-work for what would become the final piece of the theory known as the Standard Model of Particle Physics. They proposed an energy field, filling the entire Universe that gives mass to fundamental particles.

This “Higgs mechanism” neatly explained why the weak nuclear force was so weak and why light is able to travel over infinite reaches of space. It also laid the groundwork for the unification of the weak and electromagnetic forces into a single “electroweak” force, in a coup similar to James Clerk-Maxwell’s unification of electricity and magnetism in the 19th century.

Peter Higgs at CERN’s public announcement of the Higgs Boson, 4 July 2012. Credit: CERN

However, like air, the Higgs field itself is invisible; the only way to know if it is there is to create a disturbance in it, like a breeze or a sound. It was Peter Higgs who first suggested that if the field existed, it would be possible to create such a disturbance, which would show up as a new particle. Hence, the boson was named after him, much to the irritation of some of the other five theorists responsible for the theory.

The LHC’s discovery of the Higgs closed a chapter in the development of fundamental physics, placing the keystone into the great arch of the Standard Model. The LHC is currently being upgraded so that in 2015 it will reopen at almost double its previous energy. What every scientist is now aching for is a sign of something new, physics beyond the Standard Model, and most probably beyond our wildest aspirations.

This article was originally published at The Conversation (original article).

Through the past, present and future, follow the compelling drama, the amazing achievements and the inspirational hopes of the LHC at Collider, a new exhibition opening this November at the Science Museum.

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Standard Model Stands Firm

Dr. Harry Cliff, a Physicist working on the LHCb experiment and the first Science Museum Fellow of Modern Science, writes about a recent discovery at CERN. A new Collider exhibition opens in November 2013, taking a behind-the-scenes look at the famous particle physics laboratory. 

On Friday afternoon, at the EPS conference in Stockholm, two colleagues of mine from CERN stood up to announce that the search for one of the rarest processes in fundamental physics is over. The result is a stunning success for the Standard Model, our current best theory of particles and forces, and yet another blow for those hoping for signs of new physics from CERN’s Large Hadron Collider (LHC).

The Compact Muon Spectrometer, an experiment at CERN. Image credit: CERN.

The Compact Muon Spectrometer, an experiment at CERN. Image credit: CERN.

The LHCb and CMS experiments at the LHC have made the first definitive observation of a particle called a Bs meson decaying into two muons, confirming a tentative sighting at LHCb (my experiment) last autumn. The discovery has far-reaching implications for the search for new particles and forces of nature.

Beyond the Standard Model

There are a lot of reasons to suspect that the current Standard Model isn’t the end of the story when it comes to the building blocks of our Universe. Despite agreeing with almost every experimental measurement to date, it has several gaping holes. It completely leaves out the force of gravity and has no explanation for the enigmatic dark matter and dark energy that are thought to make up 95% of the Universe. The theory also requires a large amount of “fine-tuning” to match experimental observations, leaving it looking suspiciously like the laws of physics have been tinkered with in a very unnatural way to produce the Universe we live in.

In the last few decades a number of theories have been put forward that attempt to solve some of the Standard Model’s problems. One particularly popular idea is supersymmetry (SUSY for short), which proposes a slew of new fundamental particles, each one a mirror image of the particles of the Standard Model.

The Large Hadron Collider beauty (LHCb) experiment at CERN. Image credit: CERN.

The Large Hadron Collider beauty (LHCb) experiment at CERN. Image credit: CERN.

SUSY has many attractive features: it provides a neat explanation for dark matter and unifies the strengths of the three forces of the Standard Model (this suggests that they could all be aspects of one unified force, which should definitely be referred to as The Force, if it turns out to exist someday). It would also keep my colleagues in work for decades to come, thanks to a whole new load of super-particles (or sparticles) to discover and study.

However, physicists were first attracted to it because the theory is aesthetically pleasing. Unlike the Standard Model, SUSY doesn’t require any awkward fine-tuning to produce laws of physics that match our experience. This is not a very scientific argument, more a desire amongst physicists for theories to be elegant, but historically it has often been the case that the most beautiful theory turns out to be right one.

On the hunt

The decay observed at LHCb and CMS is predicted to be extremely rare in the Standard Model, with a Bs meson only decaying into two muons about 3 times in every billion. However, if ideas like SUSY are correct than the chances of the decay can be significantly boosted.

Finding particle decays this rare makes hunting for a needle in a haystack seem like a doddle. Hundreds of millions of collisions take place every second at the LHC, each one producing hundreds of new particles that leave electrical signals in the giant detectors. Physicists from LHCb and CMS trawled through two years worth of data, searching untold trillions of collisions for signs of two muons coming from a Bs meson. The pressure to be the first to find evidence of this rare process was intense, as Dr. Marc-Olivier Bettler, a colleague of mine from Cambridge and member of the LHCb team told me.

“It is a very strange type of race. To avoid bias, we don’t allow ourselves to look at the data until the last minute. So it’s a bit like running blindfolded – you can’t see the landscape around you or your competitors, even though you know that they’re there, so you have no idea if you are doing well or not! You only find out after you cross the finish line.”

However, ultimately the race ended in a draw. Neither LHCb nor CMS alone had enough data to announce a formal discovery, each turning up just a handful of likely candidates. But when their results are formally combined next week it is expected that the number of observed decays will pass the all-important “five sigma” level, above which a discovery can be declared.

Standard Model Stands Firm

In a blow for supporters of SUSY, LHCb and CMS observed the decay occurring at exactly the rate predicted by the Standard Model – approximately 3 times in a billion. This is yet another triumph for the Standard Model and kills off a number of the most popular SUSY theories.

Professor Val Gibson, leader of the Cambridge particle physics group and member of the LHCb experiment explained that, Measurements of this very rare decay significantly squeeze the places new physics can hide. We are now looking forward to the LHC returning at even higher energy and to an upgrade of the experiment so that we can investigate why new physics is so shy.”

This result is certainly not the end of the road for ideas like supersymmetry, which has many different versions. However, combined with the recent discovery of the Higgs boson (whose mass is larger than predicted by many SUSY theories) this new result may only leave us with versions of SUSY that are somewhat inelegant, meaning that the original motivation – a natural description of nature – is lost.

This new result from CERN is yet another demonstration of the fantastic (and somewhat annoying) accuracy of the Standard Model. Incredible precision is now being achieved by experiments at the LHC, allowing physicists to uncover ever-rarer particles and phenomena. If ideas like supersymmetry are to survive the onslaught of high precision tests made by the LHC experiments, we may have to accept that we live in a spookily fine-tuned Universe.