Forget Freud, research on dream imagery may help us understand consciousness

Scientists have pinned down what happens inside the brain when the scenes change in our dreams. Shutterstock

Rapid eye movements (REMs) during sleep may contribute to the visual part of our dreams by acting as a switch from image to image, researchers have found. The study, which measured the activity of individual cells in the brain in both awake and sleeping participants, is important because it is the first of its kind and provides a great starting point for uncovering the deeper secrets of human consciousness.

Consciousness can roughly be summed up as our awareness of the environment and our ability to respond to it. However, Sigmund Freud and his followers have described dreams as deep-seated, unconscious psychic desires. Today, many instead see them as an interpretation of images of the environment stored in certain parts of the brain. These images are thought to be projected onto the visual cortex so we can “see them” in our dreams.

Physiologists and experimental psychologists refer to mental images of 3D scenes as “visuospatial imagery”, which is similar to what we see when we dream. In humans, we know that direct stimulation of certain areas in the brain in epileptic patients induces dream-like images. However, combining the interpretations of dreams according to Freud with the physiological basis of dreaming into a single study is a challenging task.

The new study is based on measurement from electrodes implanted in the brains of humans for the first time, giving firsthand information about how single neurons behave in dreaming humans.

REMs happen when we are completely awake as well as when we are sleeping. The aim of the study was to compare the two in human participants to establish whether the brain activity when we sleep is similar to when we are awake. The particular brain region the researchers looked at was the medial temporal lobe – a region linked to areas that process visual awareness.

The team recorded sleep and wakefulness cycles in 19 volunteering patients with a type of epilepsy that cannot be controlled with medication. Such patients therefore have electrodes implanted in the brain that can record information so as to delineate the area responsible for the starting of epileptic seizures in order for that area to eventually be taken out surgically.

Temporal lobe lateral view BodyParts3D/Anatomography via wikimedia, CC BY-SA

The researchers used these electrodes to record REM sleep. To look at how the brain processes visual information, they monitored REM when the patients were awake – either when they were watching a DVD or interacting with people in a well-lit room. They also monitored the participants when they were awake in a dark room – meaning they did not process any visual information. As a control in which eye movements were suppressed, participants were asked to fixate on images for a short period of time.

They found that the neurons increased their firing rate in a similar way after REM sleep as they did when the participants were awake and processing visual information. There was less of a similarity, however, when the patients were in the dark. This indicates that REM during sleep or wakefulness is closely linked to the processing of visual information.

The finding could potentially mean that REMs are important units of integration that tie sleep and wakefulness – and therefore consciousness – together. Given that activity in the medial temporal lobe is closely linked with visual awareness, these results may indicate that REM during sleep could be a reflection of a switch from image to image in dreams. The findings might lead to research that combines neural, vascular and behavioural insights that help us understand human consciousness.

Neurons require energy and oxygen to function and this is brought to them by blood. Vascular data can be recorded using a type of brain-imaging technique known as functional near infrared spectroscopy which can provide an index of brain oxygenation during REM neurovascular coupling – the relationship between local neural activity and changes in cerebral blood flow that occur as a result of it.

We can combine neurovascular data during REM with behavioural data that are obtained by measuring how the brain selectively blocks visual processing during eye movements to avoid blurry images on the retina. These blurred images are useless, which is why we don’t actually see them but instead see individual frames sharply. Of course we don’t notice this because we also have the gift of accommodation (changing the shape of our lens when we look close up or far away) for most of our lives. But when we hit middle age, however, that response disappears and we can become aware of this effect.

By combining electrical and vascular recordings from neurons during REM sleep, we may be able to figure out whether the same effect takes place when we dream. Will the neurons that are briefly inactive use less oxygen? It is this intricate relationship between the different types of data that we need to couple with psychology in order to shed more light on REM, dreams and the brain’s ability to internalise the outside environment and visual space.

Recording the entire nervous system in real time will unlock secrets of the brain

Artist impression of neurons firing in the brain. Neurons by StudioSmart/shutterstock.com

There are around 100 billion neurons in the human brain, each connected to hundreds of neighbours. Analysing the link between neural activity in the brain, and the behaviour that causes it, could shed light on both areas. Now, a team of scientists has engineered imaging techniques to map neuronal firing in an entire nervous system at high speed, an approach which might one day unlock our understanding of animal behaviour.

Science has already uncovered much about the nervous system, so we have a fairly comprehensive picture of how the central nervous system (CNS) functions at the microscopic and molecular level.

The next step is to scale up our understanding of how these functions work at the level of the entire nervous system. The first nervous structural connection map of this kind, of C. Elegans, a tiny worm with only 302 neurons, was published in 1986. But today’s neuroscientists can go much further, combining structural and functional connections to understand how they operate – a field referred to as connectomics.

Making connections

Connectomics draws scientists from engineering, physics, chemistry and computer sciences into neuroscience, where a variety of techniques using advanced equipment can generate images, called multimodal imaging. We expect connectomics to unveil the biology that lies behind the mental and physical processes required when organisms execute complex tasks and, ultimately, to reveal the neural basis of our cognitive behaviour.

These images are created by probing tissues with a combination of different imaging methods, such as the MRI scanning and EEG commonly employed in hospitals. Because each method targets a different aspect of the brain, multimodal imaging is the ideal approach to generate an image that represents the functioning of an entire system.

Using these and other techniques, a team of neuroscientists have monitored neuronal network activity over the entire central nervous system of a fruit fly larva. The the fruit fly (Drosophila) larva has a central nervous system small enough to be confined within a microscope’s field of view.

Neurons firing in the central nervous system of a Drosophila larva. The time sequence goes from left to right. Lemon et al/Nature

High speed and fine detail

Engineers constructed a high-speed simultaneous multi-view (hs-SiMView) microscope, capable of taking images of anatomy on microscopic scales and recording the firing of neurons by capturing images five times every second.

The high sampling frequency is achieved by moving both the light source and detection planes together, relative to the stationary object, to create 3D image data. Using the equipment, the study’s authors were able to image the central nervous system and ventral nerve cord (like the spinal cord in mammals) of Drosophila larvae. They captured more 10,000 neurons firing while the the central nervous system was artificially excited in patterns that mimicked crawling backward and forward.

The aim was to understand how high-order control centres in the brain coordinate basic movement. The results were functional maps of neural networks in the fruit flies, highlighting how individual neurons were connected and how their firing patterns controlled movement. These neural circuit maps form the first functional connectomics ever made of the neuronal activity behind movement control at high spatial resolution. Future studies could look at other movements or circumstances and continue to build a more comprehensive map of Drosophila – a major achievement for neuroscience.

From flies to mammals

White Matter Connections obtained with MRI tractography Xavier Gigandet et al, CC BY

The US has launched the BRAIN initiative to use this kind of technology to learn more about the human brain, modelling functional systems like the retina. Being able to simultaneously detect the firing of neurons at micrometre resolution, several times per second isn’t possible yet for the complex mammalian nervous system, but projects such as the Human Connectome Project have made great progress, creating imaging hardware that suits human brain structures.

MRI is one of the key avenues of exploration due to its non-invasive nature and good resolution. Scientists working at the Human Connectome Project have provided stunning images of structural connections in human white brain matter using a dedicated MRI scanner. This is still at an early stage, yet further technical developments are likely to yield new knowledge about the structural and functional connectivity of the human brain.

Google becomes Alphabet in effort to keep the innovative spark alive

Google: no longer just a search engine. mwichary/flickr, CC BY

In the corporate world you learn quickly that if small companies want to collaborate, it tends to happen, while efforts to collaborate with large companies may involve many meetings and involve many people with no guarantee anything will come of it. Small companies innovate as they need to; big companies are often risk averse.

Google’s announcement that it is to reorganise under a new parent company, Alphabet, is a step towards overcoming this sort of bureaucracy and maintaining the fiercely innovative and daring streak that has until now been its trademark.

Large companies have more freedom to ignore their end users, preferring secrecy from fear of having their ideas stolen, and instead focus on large stakeholders. This means that they often create products that are too wide in scope and which fail to address specific needs.

For smaller businesses, innovations are part of the way they engage with customers. Rapid prototypes are released, and assessed to see what works and what doesn’t. These prototypes are then scaled up and made relevant to a wider range of potential customers. Despite its enormous size and wealth, this is also the approach that Google favours.

Too often large companies don’t trust their engineers to make sensible judgements on business decisions. This probably shouldn’t be the case, as often the most successful technology companies are run by those who worked up through a technical role. Companies such as Hewlett Packard, Apple and Google made their names through being technically excellent, rather than a narrow focus on business objectives.

Google’s move effectively splits one monolithic company into several smaller companies wholly owned by Alphabet, of which Google is the largest. In this way, Google (or should we say, Alphabet) hopes to keep each of its areas of focus small, fast, and innovative.

G is for Google. Let’s hope M isn’t for mistake. Alphabet

Risk averse

After all, Google is not just a search engine any more. It has expanded in many directions, from mobile phone design and operating systems, to smart home control kits, automotous cars, geomapping, and off-the-wall projects. It is comfortable trying things out and dedicating the resources to ideas with potential.

This risk-taking is a key part of Google’s innovation infrastructure, giving independence of thought to staff and technical leaders without over-burdening them with business issues. In fact, it’s similar to a traditional academic research model, where academics with good ideas get the resources that allow them to drive them forward. Done well, the university becomes a leader in the field, just as Google has become a technology giant.

Small works in software

Google wants to attract the best staff into research labs, and achieves this by creating a small-company infrastructure where engineers are not burdened by bureaucracy. However, unlike smaller businesses, Google has the deep pockets to support its staff. A rising star can be given responsibilities without the need to progress through a formal hierarchy.

After all, the structure of large companies may limit their ability to produce useful software – take for example the many major government IT contract disasters, such as the £10 billion spent on an NHS IT system that ultimately never worked.

What would a small company have done differently? It would have invested time in searching for the best solution, created and tested prototypes, and used those as a basis for the final product. The large companies involved in the NHS contract had off-the-shelf solutions, which they pushed without questioning their suitability. Too much money was spent on design and requirements analysis, and it was years before the product reached the clinical staff, by which point it was a computer programmer’s dream but a nightmare for the intended user.

Reputations built on people

Leading universities generally have individuals to thank for their success – for examples cryptography at Royal Holloway, led by Professor Fred Piper, and the University of Edinburgh’s Informatics Group that thrived under the guidance of Professor Sidney Michaelson.

So big companies need to act like small ones and provide opportunities for innovation and risk-taking to thrive, where individuals who do not want to conform to strict rules and procedures can take on their vision of the future. After all, Apple was a garage company once, and Microsoft had to borrow someone else’s operating system (known as 86-DOS and purchased from Tim Paterson of Seattle Computer Products) to get a foot on the ladder.

Google’s enormous impact is mostly down to the creativity of individuals, its image still one of a bunch of software developers who just love to write code – not easy for a company whose products increasingly find places in almost every web user’s life. Let’s hope that the creation of Alphabet protects the small-company ethos that has made Google great.

World's most powerful laser is 2,000 trillion watts – but what's it for?

Lasers, going where no one has gone before. Damien Jemison/LLNL, CC BY-SA

The most powerful laser beam ever created has been recently fired at Osaka University in Japan, where the Laser for Fast Ignition Experiments (LFEX) has been boosted to produce a beam with a peak power of 2,000 trillion watts – two petawatts – for an incredibly short duration, approximately a trillionth of a second or one picosecond.

Values this large are difficult to grasp, but we can think of it as a billion times more powerful than a typical stadium floodlight or as the overall power of the all the sun’s solar energy that falls on London. Imagine focusing all that solar power onto a surface as wide as a human hair for the duration of a trillionth of a second: that’s essentially the LFEX laser.

LFEX is only one of a series of ultra-high power lasers that are being built across the world, ranging from the gigantic 192-beam National Ignition Facility in California, to the CoReLS laser in South Korea, and the Vulcan laser at the Rutherford Appleton Laboratory outside Oxford, UK, to mention but a few.

There are other projects in design stages – of which the most ambitious is probably the Extreme Light Infrastructure, an international collaboration based in Eastern Europe devoted to building a laser 10 times more powerful even than the LFEX.

So what is driving scientists all over the world to build these jewels of optical and electronic technology? What is enough to convince politicians to allocate such significant research funds to back these enormous projects?

Recreating the early universe

Well, the first reason that comes to mind is because the “wow factor” that is associated with lasers. But there’s a whole lot more than just exciting scientists’ and enthusiasts’ imagination.

Lasers this powerful are the only means we have to recreate the extreme environments found in space, such as in the atmosphere of stars – including our Sun – or in the core of giant planets such as Jupiter. When these ultra-powerful lasers are fired at ordinary matter it is instantaneously vaporised, leading to an extremely hot and dense ionised gas, which scientists call a plasma. This extreme state of matter is extremely rare on Earth, but very common in space – almost 99% of ordinary matter in the universe is believed to be in a plasma state.

Ultra-powerful lasers allow us to create a small replica of these extreme states and objects from the universe in such a way that they can be studied in a controlled manner in the laboratory. In a way, they allow us to travel back in time, since they can recreate the conditions found in the early universe, moments after the Big Bang. These extremely dense and hot environments, which only ultra-powerful lasers can create, have already taught us a lot about the evolution of our universe and its current state.

Uses closer to home

One of the acceleration beams of the LFEX laser in Osaka. Osaka University

On a more practical note, laser facilities are not only interesting for their input into theoretical research, they’re also at the core of crucial practical applications. For example, current research into alternative and clean energy generation or healthcare. The LFEX is mainly applies to the former, since it is built to study nuclear fusion research.

Unlike nuclear fission, nuclear fusion does not generate radioactive waste. This means fusion fuels are much easier to store and handle – we can use seawater and lithium, somewhat handier and easier to come by than uranium.

Nuclear fusion is what creates and sustains the immense energy of stars, but it requires a significant input of power to initiate the chain reaction. High-powered lasers such as LFEX are the best candidates for the job. In fact preliminary results are encouraging, with a test at the US National Ignition Facility managing to generate more energy than it expended on one occasion last year.

Inexpensive particle research

This class of ultra-powerful lasers is also extremely appealing because they represent a much more compact and inexpensive (by comparison) alternative to the huge particle accelerators such as at CERN – which measure many kilometres in length. High-powered, laser-driven particle accelerators can generate ultra-high quality x-rays without the need to use radioisotope particles which need careful handling. These laser-driven x-rays can then be used for taking high-resolution images of biological tissues in a really compact and inexpensive system. For example, this laser-driven tomography of an insect.

Researchers are also now working on using laser-driven ion beams for cancer therapy. This technique has so far been restricted due to the cost and size of conventional accelerators. Laser-based cancer therapy would be affordable to a much larger number of hospitals, bringing this effective cancer therapy technique to a much larger number of patients.

So the ultra-high power that LFEX can deliver, if only for the briefest of moments, is not just a fancy new toy but an exciting step forward in applying laser technology to a wider range of disciplines – from the the seemingly abstract world of the early universe, to the very real uses providing the tools to diagnose disease or fight cancer.

Night sky puts on a meteor shower to celebrate Rosetta's closest approach to the sun

A sacred moment for stargazers: the Perseid meteor shower in August, 2009. Tatyana Zenokovich/EPA

A firework display is often the finale of a celebratory event, something that many people can experience and enjoy at the same time. This week, the 9 – 14th August, we should be seeing a firework display with a difference: rather than sparks shooting from the ground upwards, they will be falling downwards. And there is actually something worth celebrating up there, as comet 67P/Churyumov-Gerasimenko simultaneously reaches its closest approach to the sun.

The Perseid meteor shower, which reaches its maximum on 12 August, is an annual event in the northern hemisphere which frequently garners media attention, mainly because it occurs in the middle of the summer holiday. A story about cosmic fireworks is a sure winner for a slow news day, especially given that people may be away from city lights, and able to see the night sky more clearly than usual.

Meteors, or shooting stars, are dust particles the size of sand grains that travel through the atmosphere, about 50 miles above the Earth’s surface. They move fast – some 20-30 kilometres per second – and friction between the particle and the atmosphere at that speed causes them to heat up, emitting light. The grains aren’t burning up, they are evaporating into a plasma, which exists for a split second, before extinguishing.

The 1833 Leonids meteor shower depicted for the Adventist book Bible Readings for the Home Circle. wikimedia

Nothing lands from a meteor. And neither do they go bang like a firework – the most they might do is sizzle a little bit – but you would have to be somewhere extremely quiet to hear them. A shooting star is generally white, but they can be coloured, mainly green or orange depending on their composition. Orange is from sodium, the same colour that stains the night sky in cities, with reflected light from street lights.

On most nights of the year, around six meteors per hour can be seen, assuming the skies are clear. These sporadic meteors emanate from random bits of dust from asteroids or comets. At certain times of the year, though, the count goes up to more like 100 meteors per hour. Such meteor showers or storms are connected with specific comets, which is why we are able to predict them.

The Perseids are associated with comet Swift-Tuttle, which takes 133 years to travel around our solar system. It was last at perihelion (its closest approach to the sun) in 1995. Each time the comet comes to the inner solar system, it sheds dust. Over time, this debris has built up, and is smeared out along the entire track of the orbit. Once a year, in August, the Earth’s orbit crosses that of comet Swift-Tuttle, and dust from the comet is captured.

If you record a meteor shower, it seems as if all the tracks come from a single point – the radiant. For the Perseids, the radiant is in the constellation of Perseus, which is in the north-east part of the sky. The shooting stars aren’t coming from Perseus, they just appear to be, in the same way that the parallel tracks of a railway line appear to converge as they disappear into the distance.

Radiant in a meteor shower. Anton, wikimedia., CC BY-SA

All eyes on 67P

At the same time that the Perseids are lighting up the night skies, 67P reaches its perihelion – the point at which its activity is expected to be at its highest. This is a prime focus of the Rosetta mission: the spacecraft has been travelling alongside 67P for a year, observing development of the comet’s tail, how the nucleus has outgassed and where jets have formed.

Over the past few months we have been treated to amazing images of the nucleus, and the spacecraft has had to retreat further and further away from the comet as the amount of dust increased, causing a hazard to the navigation systems. I must make it clear that even though I have linked them in this column, the Perseid meteor shower is not connected with comet 67P or the Rosetta mission.

In the approach to perihelion, Rosetta has recorded growing activity from 67P, including this powerful jet. ESA

Over the coming year, Rosetta will watch as the comet moves away from the sun, causing the tail to die away and the surface to re-freeze. Then, the spacecraft will be able to get closer to the nucleus again. We should hear more from the Philae lander (assuming communications get sorted out), and see additional fantastic pictures of the comet’s rugged surface.

What we probably won’t see is a display of cometary fireworks from the Perseids. In the UK, at least, the prediction of a storm of shooting stars is almost inevitably the cue for a week of unbroken cloud. Still, if you are in the northern hemisphere, look to the north-east after midnight – and if you wish to wish upon a shooting star, I hope you manage to see at least one.

Disclosure

Monica Grady receives funding from the STFC and is a Trustee of Lunar Mission One

Graphene is missing ingredient to help supercharge batteries for life on the move

Graphene could have a radical influence on the future of energy storage. graphene by nobeastsofierce/shutterstock.com

While our gadgets these days are constantly getting smaller and more powerful, the development of commercial batteries both small enough and with sufficient capacity to feed their power-hungry demands has not quite kept pace.

Most people will have heard of Lithium-ion (Li-ion) batteries. They’re in almost all mobile electronic devices – from your mobile phone and laptop, through to back-up power supplies on jets and even spacecraft. Surprisingly though, despite this huge demand, the fundamental design of Li-ion batteries has remained broadly similar in recent years.

Battery life is frequently the constraining factor in many existing and experimental applications. It’s key for the future of technologies such as electric cars, and for high-capacity energy storage for renewables such as wind and solar power. In fact the comparatively slow progress with developing new batteries has resulted in many electronics manufacturers turning to trying to reduce or maintain their products’ power requirements to find a balance.

Which is not to say that there’s no research into new energy storage techniques. Far from it in fact. The past few decades have seen an explosion of research in this area. Unsurprisingly, a good deal of this revolves around improving Li-ion batteries. The new “wonder material” graphene has also been suggested as a possible key to the solution. Graphene has number of interesting properties that have led researchers to suggest either modifying components of Li-ion batteries, or using graphene as the energy-storage medium instead as promising solutions.

Just add graphene

Graphene has also been used to develop electronic devices with extremely low power requirements. This is possible (in part) because pure graphene has the lowest resistivity of any known material at room temperature – devices made of pure graphene can conduct electricity more efficiently than any other material (at room temperature). As a consequence, very little energy is wasted.

Devices built with graphene would not experience the same problems of heating faced by current electronics – they could run indefinitely with very little increase in temperature. Heat is bad for electronics; it means energy is being wasted and it often serves to reduce the efficiency of the device further as it heats up. Pure graphene virtually eliminates energy losses of this kind, which makes devices produced from it extremely energy-efficient. For consumer electronics, this could mean significantly more powerful devices with massively improved battery life – a win-win scenario if ever there was one.

What’s more, studies indicate that using graphene to replace or enhance components of Li-ion batteries can significantly improve the energy density and longevity of the battery. One popular technique has been to make the anodes or cathodes in Li-ion batteries out of graphene.

Supercapacitors of various sizes – but none of them small enough, yet. Maxwell, CC BY-SA

Your next battery may be a supercapacitor

Another technique is to use graphene as the energy-storage medium itself. This has been used to construct supercapacitors – perhaps the strongest future competitor to Li-ion batteries in uses that require very rapid charge times, such as in the case of electric cars.

This is arguably their critical feature. A supercapacitor can go from fully discharged to fully charged many orders of magnitude faster than comparable Li-ion batteries. In this context, it is the large surface area of graphene that is important, because the amount of charge that can be stored is related to the surface area of the materials from which it’s made. So again, graphene is ideal.

Despite supercapacitors’ potential to challenge the ubiquitous Li-ion battery, current supercapacitors are invariably too large and too expensive to replace them in the same roles. However, prototypes indicate that superconductors may meet the requirements necessary to replace conventional batteries in the not too distant future.

Ultimately, the challenge with any of these prototypes is the ability to scale production to meet the demands of the consumer electronics industry. Graphene-based solutions have so far been notoriously difficult to manufacture on a large scale, thanks in part to the difficulty of isolating high-quality graphene. Nevertheless, the future for energy storage and energy-efficient technology looks bright. Whether graphene ultimately plays a part in the revolution or not, its clear that the research into these technologies will eventually lead to the introduction of cheaper and more durable products with a higher capacity.

It’s no understatement to say that an energy revolution awaits as a result of next-generation energy-storage devices, which could help usher in the age of fully electric vehicles, large-scale renewable energy generation and the end of our reliance on fossil fuels.

How science lost one of its greatest minds in the trenches of Gallipoli

A young Henry Moseley in the lab. wikimedia

August 10, 1915. The Gallipoli sun beats down on the back of a Turkish sharpshooter. He is patient and used to the discomfort. He wipes the sweat from his eyes and peers back down the sight of his rifle, sweeping back and forth across the enemy lines. He’s hoping to spot a target worth taking a shot at as each muzzle flash risks giving his position away.

His sight settles on the shoulder pip of a second lieutenant. The target bends down out of sight, then reappears, now with a phone at his ear. He stands still as he sends his dispatch. It’s an easy shot for the sniper. He squeezes the trigger and yet another young man dies.

Infantry from the British Royal Naval Division in training during the Battle of Gallipoli. wikimedia

The Turkish soldier settles down in his hole, pleased with his marksmanship. He wonders if he’s made a significant difference to the war effort (probably not).

However, he may well have caused the single most costly death of the entire war. His victim, now lying in a trench on a peninsula in Turkey, is 27-year-old Henry Moseley. The loss to science is incalculable.

Hidden patterns

Despite his young age, Moseley had already made a stunning contribution to chemistry and physics. It is thanks to him that that the periodic table looks the way it does today.

He had graduated from Oxford just five years before his death. Immediately after graduating he was employed as a teaching assistant by the great physicist Ernest Rutherford in Manchester. Moseley hated it, describing his duties as “teaching elements to idiots” and his students as “mostly stupid”. His real passion was research, so in his spare time he used his energies to set up his experiments.

Moseley was working in an era of physics that was concerned with the power of X-rays. The Braggs, a father-son team working in Leeds, were developing X-ray crystallography. This allowed science to probe the atomic structure of molecules.

But instead of jumping on that bandwagon – shining X-rays at crystals to work out chemical structures – Moseley turned his attention to the elements themselves. He studied the X-rays the elements gave off when bombarded with electrons. His results had major implications for the famous periodic table in which elements are presented.

Back in 1869, Dimitri Mendeleev arranged the elements in a logical fashion. He ordered them by weight and then laid them out in a table. Next he shuffled the dimensions of his table to take similarities of elements into account. For example, lithium, sodium and potassium have similar chemical properties and were arranged in one group on a line of the table (modern tables have been flipped so that these groups are now in columns).

Mendeleev’s periodic system. wikimedia

Likewise for fluorine, chlorine, bromine and iodine. And so the periodic table was born. The elements were now arranged in a clear sequence – and each was given an atomic number denoting its position in that sequence. But there were a few problems, some elements didn’t quite fit the order. Their behaviour suggested one position in the table, but their atomic weight put them somewhere else. So the atomic weight and atomic number of the elements didn’t quite correlate.

In Manchester, and later in Oxford, Moseley took samples of all known elements, from aluminium to gold, and measured the X-rays they gave off after bombarding them with electrons. He discovered that each element emitted a distinct frequency of X-rays, and that this frequency correlated with the atomic numbers. When he plotted the square root of the frequency, against the atomic number everything fell into straight lines on his graph.

For the first time it became clear that an element’s atomic number, corresponding to its position on the table, had a basis in physics and was not merely a convenient label. And that these numbers (confirmed by Moseley’s measurements) resolved the previous issues with the periodic table. He also noted points missing from his graph and surmised that these gaps must be due to yet-to-be discovered elements. It was wasn’t until 30 years after his death that that the last of Moseley’s missing elements were discovered.

Nobel effort

Moseley’s achieved all this in a research career lasting just 40 months. At the outbreak of war in 1914 he signed up, becoming a signalling officer in the Royal Engineers. Had he survived, it is likely he would have been awarded the 1916 Nobel Prize in Physics (as it was no Nobel Prize in Physics was awarded that year). There is no telling what other breakthroughs might have been achieved in the alternative history in which he survived the war.

There is one more legacy that Moseley left. His death raised the question of whether great minds such as his should really be risked on the battle field. Despite the war, the international scientific community was outraged at the loss of such a renowned scientist, who still had so much to offer.

From then on scientists were used in a very different way in wars. For better or worse scientists in the next great war developed penicillin, radar, programmable computers and, of course, the Manhattan project. All these inventions had much greater impacts on World War II than any of the individuals involved could have made at the front line.