The best video games need not imitate films to be worth a Bafta

Games and films, one award to award them all. Andy Rain/EPA

With the spectacle delivered by increasingly photo-realistic video games with budgets running into tens of millions of pounds on a par with that of the film industry, it seems only right that video games should be offered awards by the same organisation, the Baftas.

On the list of nominees for the British Academy Games Awards this year are many “AAA” titles such as Middle-earth: Shadow of Mordor, Alien: Isolation and Far Cry 4, each demonstrating extraordinarily realistic visual representation involving soundscapes and inspiring technical ambition. These are massive, detailed open worlds to explore, with expansive multi-player options.

Not so novel

Yet there is much that is familiar in these nominations. Franchises such as FIFA football, the Call of Duty first-person shooter and the Forza racer are commercial goldmines that are revisited annually to generate predictable profits. But this discourages risk-taking. Each new iteration of an established title is often little more than a re-skin, a buff-and-polish. This is as much to do with audience expectations of the game they’re getting as it is testament to the development costs required to exploit the technical power of the latest consoles.

Atmosphere? Alien: Isolation has it in spades. The Creative Assembly

Of course such valuable pieces of intellectual property require a safe pair of hands. Game developer studios can’t afford for an instalment to fail, and this commercial need encourages a very conservative approach. This isn’t necessarily a bad thing for the industry, as the profits from established titles can be reinvested in developing new ideas. For example Bungie, the studio behind the hugely successful Halo series, also created Destiny, which expands a typical first-person shooter into a multi-player online game with role-playing elements in an immersive, persistent game universe.

Far Cry 4: good, but more-of-the-same good. Ubisoft

Yet despite the technical accomplishment of next-gen games such as Destiny and the mechwarrior-style Titanfall, many players look for novelty and a different type of challenge. Some games nominated for an award represent very traditional concepts of play. For example, incarnations of classics such as Nintendo’s ever-popular Mario Kart (now up to the eighth instalment), and a simplified version of the retro-themed Minecraft for games consoles illustrate the enduring appeal of old school game mechanics and characters over games that sell themselves on photo-realistic environments.

Still, as in the world of film, it often seems that once again we’ve been seduced by the polish of sequels and derivatives rather than risky new ideas.

Minecraft’s retro appeal has found stella success. AdultsOnlyMinecraft

Indie invasion

So I’m pleased to see much smaller games from indie developers among the shortlist. The explosion of computing power in our pocket via mobile phones and tablets has prompted a new wave of creativity throughout the game industry. With far lower costs to develop games for mobile platforms, the opportunity is there for smaller studios and independent developers (often individuals) to enter the market with interesting, unusual, or downright idiosyncratic games. Big budget games may be technically impressive with their realistic physics engines and lighting, but it’s often the smaller studios with tiny budgets that deliver real innovation.

Some of the nominations this year challenge the orthodoxy in a beautiful way. Lumino City by Camberwell-based State of Play is a great example of a novel approach to graphic style. The painstaking effort to cut and construct a paper-based set provides a truly refreshing environment. It reminds us of the simple pleasures of classroom craft but enhanced in ways we could only dream of as children.

Nominated in four categories, Inkle’s adventure game 80 Days has been lauded for its elegant storytelling and rich interactive narrative. The game isn’t ashamed of its pedestrian pace, using it as a device to enhance the unravelling of the story.

Compelling gameplay doesn’t have to mean breakneck speed and bullet-dodging action; nor, as the regular use of self-deprecating humour in 80 Days demonstrates, do contemporary games need to take themselves so seriously.

Oliver’s journey in 80 Days involves some unlikely characters. Frogwares

The intricacies of the game’s plot – to travel round the world in 80 days, like Phileas Fogg – creates a world that can be explored repeatedly not just to improve on a score, but in order to continue discovering new elements missed on previous run-throughs.

The 25% industry tax breaks for games with a British “cultural value”, finally awarded last year after a seven year legal battle, should encourage more newcomers to the games industry. And as mobile platforms spread more widely, we will hopefully see fewer blockbuster sequels in the future and more small but perfectly formed sensations like Lumino City and 80 days.

Regardless of whether the games enjoy a large or small budget, the Games Baftas should serve to remind us of the enormous versatility, skills and innovation within Britain’s creative industries. Each year UK talent produces some of the world’s most successful video games, which contributes billions to the economy. The British video games industry is a homegrown success story dating back to the 1980s, but which is continually enriched by the range of excellent design and development courses at UK universities today – long may it contiune.

Saturn's moon Enceladus could be another location for life beyond Earth

With geysers bursting through an icy crust, Enceladus is a tiny moon with a big personality. Hsiang-Wen Hsu et al/Nature, Author provided

The Cassini mission that has investigated Saturn since 2004 has revealed much about the giant planet and its many moons. Perhaps most tantalising is the discovery that the moon Enceladus is the source of strong geysers ejecting plumes of water and ice.

A new study of Cassini data published in Nature by Hsiang-Wen Hsu and colleagues reveals these plumes are laced with grains of sand. This indicates that hydrothermal activity may be at work in Enceladus' sub-surface ocean, and propels this tiny moon into the extremely exclusive club of locations that could harbour life.

The club’s only current member is Earth, of course – although it’s very possible that Europa, one of Jupiter’s moons, is, like Enceladus, also a candidate. What they have in common is that they host liquid oceans of salty water that exists in contact with a rocky, silicate seabed from which the oceans can absorb complex minerals and elements.

A bit of a geyser

With a diameter of just 500km Enceladus is nevertheless the sixth largest of Saturn’s more than 60 moons, orbiting at a distance of just two planet-widths. Cassini has shown that Enceladus is the source of huge geysers of neutral water-rich gas and ice grains erupting at a rate of 100-300kg per second. This makes Enceladus the second most active object, after Jupiter’s moon Io which ejects one tonne per second of sulphur-rich material.

How the plumes are formed, from beneath Enceladus' surface. NASA

Gravity measurements have shown that there is at least a local and possibly a global ocean under Enceladus’ icy crust, and some of the emitted grains are rich in sodium salt, which indicates the presence of a salty ocean. Now we also discover that some are silicate-rich, and analysis shows that these may have been produced close to hydrothermal vents at temperatures above 90°C. This raises the interesting comparison with hydrothermal vents on Earth, which may have played a role in the origin of life on our planet.

The recipe for life

For life as we know it to exist, four key ingredients are important: liquid water; the right chemistry involving the elements carbon, hydrogen, nitrogen, oxygen, phosphorus and sulphur; a source of heat; and enough time for life to develop. While we know these conditions exist on Earth, planetary research throughout the solar system shows that it may exist on other objects too, and the details from this paper pushes Enceladus towards the top of the list.

We know liquid water oceans exist on several objects in our solar system. These include Earth with its surface oceans, and Jupiter’s moons Europa, Ganymede and Callisto, and Saturn’s moons Titan and Enceladus where the oceans are below the surface. Water has also played a vital role in Mars’ history: Geronimo Villanueva and colleagues recently showed that there may have been enough water on Mars to cover the planet in an ocean 137 metres deep around 3.8 billion years ago –- about the time when life was starting on Earth.

The view from Cassini towards the geyser region of Enceladus. NASA

There may also be water on the dwarf planets Ceres and Pluto, Neptune’s moon Triton, and several other objects in the solar system – but only further investigation will tell. Two other objects have lakes and oceans, but not of water. Titan has lakes of methane and ethane, for example – the only extraterrestrial object we know of with liquid on the surface – and volcanic Io has a subsurface ocean of liquid magma.

A shortlist for extraterrestrial life

So where are the best places to look for life in our solar system? The short list now seems to be Mars, Europa and Enceladus. At Mars the most likely time for life to have existed is 3.8 billion years ago when water was present, so the ESA-Russia ExoMars rover due for launch in 2018 will focus on drilling 2m below the present surface’s harsh oxidising and radiation-rich environment to search for buried evidence from the past. It carries our PanCam instrument which will provide context for the mission.

As for right now, Mars may be a less good candidate for life. Following a catastrophic collision about 3.8 billion years ago the planet underwent massive climate change, volcanic activity stopped, and the planet’s magnetic field disappeared. But the recent confirmation by Curiosity of the presence of methane is tantalising. At Europa, ESA’s JUICE mission and the proposed NASA Europa Clipper may bring more clues in the 2030s, but further missions to Enceladus have yet to make it past the proposal stage.

Nevertheless, this leaves Europa and Enceladus as prime sites where conditions may be suitable for life to exist now – but who knows which other solar system objects could be the next to join the club.

What will we find next inside the Large Hadron Collider?

What lies within? Maximilien Brice/CERN, CC BY-NC

The Large Hadron Collider, the world’s largest scientific experiment, is due to restart this month after two years of downtime for maintenance and upgrading. There’s no doubt that having played its role in the discovery of the Higgs boson in 2012, what the media christened the “God particle”, expectations for what the 27km particle accelerator at CERN could achieve this time have certainly been set high.

The Higgs boson is a possible explanation for the origin of mass, something predicted in 1964 by Peter Higgs and several other physicists, and the discovery of which led to the award of a Nobel Prize for physics for Higgs and François Englert in 2013.

So why did it take so long to discover it? As Einstein showed in his mass-energy equivalence (E=MC²), the mass of a particle is a measure of its energy content. If a particle is more massive, it has a greater energy content, and conversely to create a massive particle requires a great deal of energy. So simply put, it wasn’t until the Large Hadron Collider (LHC) was capable of colliding beams of protons with sufficient energy that the Higgs Boson could be created with its mass of 126 billion electron volts (gigaelectronvolts, or GeV). In particle physics it is usual to give masses in terms of energy, and while 126GeV is equivalent to only 2.24x1025kg, this mass is about 127 times larger than a single proton.

So the intention is that following a two-year upgrade the LHC’s new, more powerful electromagnets will be sufficient to accelerate two beams of protons to 6.5 trillion electron volts (teraelectronvolts, or TeV), increasing the potential collision energy from 8TeV in 2012 to 13TeV. And with greater collision energy comes the possibility of creating and detecting new particles of even greater mass. The expectation is that the LHC’s experiments could uncover new particles known as Z particles, new Higgs bosons, and even particles of dark matter.

A map of subatomic particles, known and hypothesised. MissMJ, CC BY-SA

From Higgs to Z

Discovered at CERN in 1983, the Z particle 0 removed for clarity, sure it doesnt matter is a force carrier – a particle that carries one of the four fundamental forces of nature: the gravitational, electromagnetic, strong and weak forces strong/weak forces are fundamental forces? arent' they just a measure? - no one works at the atomic level, one subatomic. everything has silly names these days (quarks are top bottom charm fast slow, etc). The Z particle carries the weak force, which is implicated in subatomic reactions. A related, theorised particle that could be next to be discovered is the Z prime particle, or Z'. This would help our understanding of gravitons, the carriers of the gravitational force that are theorised but have not yet been detected.

Taking the constituents of the universe as a whole, we have a good understanding of about 5% of it. The remaining 95% is made up of about 68% dark energy and 27% dark matter. With a little over 84% of the universe’s mass being dark – not detectable by any known means – if the LHC can in some way shed some light on the nature of this matter it will move our understanding of the universe forward.

With an upgraded LHC able to provide higher collision energies and the possibility of creating new particles – whether those currently theorised or not – it will have a significant impact on our fundamental understanding of the laws of nature and the accepted model that is used to try and explain them.

Some may point to the cost of the LHC upgrade, estimated at around £70m, as a cost beyond the public purse in these cash-strapped times of austerity. But the possibilities for what it can add to our understanding of the world cannot be ignored either, nor the benefits they might have in other areas, for example medical imaging. Considering how regularly sums far larger than £70m of taxpayers' money are squandered, CERN’s role as a global educational tool for physicists, mathematicians and engineers must be considered excellent value for money.

Why are cacti so juicy? The secret strategy of succulents

Blooming marvellous: cacti are among the few plant species that can thrive in the desert Alan Levine/Flickr, CC BY-SA

Sunlight, harnessed by plants in the process of photosynthesis, powers almost all life on earth. Special adaptations allow certain plants to store up a battery of carbon dioxide overnight for use in photosynthesis during the day, giving them a juicy advantage in dry desert conditions.

The processes that constitute life – such as growth, repair, movement and reproduction – all require an energy source. The immediate source of this energy for many living things is chemical energy.

High-energy carbon-based molecules, such as sugars and fats, are broken down to power the processes of life. These high-energy molecules don’t naturally occur in the environment. Work-shy and dishonest organisms, such as humans, rely on stealing high energy molecules from other organisms by eating them. Ultimately, however, more high energy molecules are required to replace those broken down.

While sugars and fats sadly don’t rain down from space, energy-rich photons (the next best thing) do, in the form of sunlight. More responsible organisms than us, such as plants and algae, perform photosynthesis. This process uses energy from sunlight to regenerate high energy molecules from their breakdown waste product, carbon dioxide (CO₂), which is constantly released into the atmosphere by all living things.

In the most common form of photosynthesis, CO₂ is taken up into leaves during the day via tiny pores in the plant surface. It is then attached, or “fixed”, straight onto a sugar molecule using energy from sunlight, to be used as a source of chemical energy – either by the plant, or by the animal that eats it.

Tiny pores let carbon dioxide into the leaf – but also allow oxygen in and water out Photohound

But acquiring CO₂ from the atmosphere can be problematic in some situations. Opening the pores on the plant surface lets CO₂ in, but also lets oxygen in and water out. Water loss is a problem in dry environments – particularly during the day, which is when CO₂ is required for photosynthesis.

Additionally, in hot environments, the plant is less able to discriminate between oxygen and CO₂ and can actually end up attaching oxygen to the sugar molecule. Once an oxygen molecule is fixed to a sugar, it must be prised off again at significant energetic cost, reducing the net energy that plants can acquire from photosynthesis.

Carbon dioxide batteries for efficiency

Several groups of plants have evolved that do not directly fix atmospheric CO₂ to make sugars, but attach CO₂ onto other molecules which can be stored, transported and broken down to release CO₂ again, like a battery. This avoids the problems of water loss and accidental oxygen fixation.

Two alternative strategies have evolved to make use of this ability: C4 photosynthesis, which manipulates the concentration of CO₂ in space, and CAM photosynthesis, which manipulates the concentration in time.

C4 photosynthesis is performed by 7,600 species, most of them grasses, including maize and sorghum. It has evolved independently at least 60 times, yet is present in less than 0.5% of plant species. Although highly competitive in hot environments, the energetic costs associated with carbon storage mean that plants carrying out conventional photosynthesis have the edge at lower temperatures.

C4 photosynthesis uses a special enzyme to fix atmospheric CO₂ onto an acid. This enzyme is much better at discriminating between CO₂ and oxygen than the classic enzyme used in traditional photosynthesis. The acid is transported deep inside the plant, where concentrations of oxygen are much lower, and the CO₂ is re-released. In this low-oxygen environment, the plant makes fewer oxygen-fixing mistakes, increasing the efficiency of photosynthesis. There is an energetic cost to this roundabout way of doing photosynthesis, but this is more than offset by the decrease in costly oxygen fixation in hot environments.

Cacti and pineapple plants use CAM photosynthesis to stay juicy. hiyori13/Flickr, CC BY-SA

The other alternative kind of photosynthesis is CAM, or Crassulacean Acid Metabolism, which predates C4 photosynthesis by at least 150 million years. This was first discovered in the Crassula family of plants but has evolved independently in many lineages of plants, totalling over 9,000 species.

Like C4 plants, CAM also stores CO₂ in an acid, but it performs this reaction at night, and rather than transporting the acid molecules to a different part of the plant, it simply stores them in the vacuole – the storage area at the heart of each plant cell. During the day, when the light required for photosynthesis is available, the plant doesn’t need to open its pores: it has a packed lunch already stored in its cells. This allows the plant to perform photosynthesis without opening its pores during the day, massively reducing the amount of water lost.

This is how CAM plants such as cacti and pineapples can remain succulent and watery despite the hot environments they grow in. In wetter or cooler environments, however, the problems solved by CAM and C4 photosynthesis aren’t as severe – and the energetic cost of storing and re-releasing CO₂ means the plants are only competitive with their traditionally photosynthesising cousins in hot or dry environments.

Perhaps the very last place, therefore, that one might expect to find CAM plants is underwater, a pretty wet environment by all accounts. It was with some surprise therefore that CAM was first reported in the lake plant Isoetes followed by discoveries in four other genera of aquatic plants.

Tiny aquatic plants of the genus Isoetes carry out CAM to concentrate carbon dioxide in the underwater world US Fish & Wildlife Service

Despite their very different environments, plants in lakes and deserts ultimately share the same problem –- the difficulty of acquiring CO₂. While a lot of CO₂ can be dissolved in water, it diffuses far more slowly than in air, so the water around a plant can become depleted of CO₂. Aquatic plants have evolved CAM photosynthesis so that they can continue taking up CO₂ at night, using it to supplement that which they can acquire during the day.

In addition to research aiming to introduce C4 photosynthesis into rice, there has been significant interest in modifying crop plants to perform CAM photosynthesis so they can better survive droughts caused by climate change.

Goodbye P value: is it time to let go of one of science's most fundamental measures?

Clinical trials rely on statistics to show whether drugs are more effective than placebo pills. But how can we be certain? Semmick Photo/Shutterstock

How should scientists interpret their data? Emerging from their labs after days, weeks, months, even years spent measuring and recording, how do researchers draw conclusions about the results of their experiments? Statistical methods are widely used but our recent research in Nature Methods reveals that one of the classic science statistics, the P value, may not be as reliable as we like to think.

Scientists like numbers, because they can be compared with other numbers. And often these comparisons are made with statistical analyses, to formalise the process. The broad idea behind all statistical analyses is that they allow the researcher to make somewhat objective assessments of the results of their experiments.

Which drug is more effective?

Scientists often conduct experiments to investigate whether there is a difference between two conditions: do people get better more quickly after taking the blue pill (condition one) or the red pill (condition two)? The most common method for assessing if the pills differ in their effectiveness is to undertake statistical analysis of where some patients were given the blue pill and some the red, and from this determine whether there is strong evidence that one colour is more effective than the other.

To assess experimental results, scientists very often use a “P value” (P is for probability). This is used to show how convincing these results are: if the P value is small, they think that the findings are real and not just a fluke. In our pill example, if P is small this is considered good evidence that there is a difference in effectiveness of the two colours of pill.

Although P is never proof that there is a difference – scientific studies never prove things, they only provide a degree of evidence for them – studies with low P values are thought to be convincing, and so are not often repeated to be sure the results are correct. This might seem reasonable because there is limited money and time in science – results from a study that seem very clear perhaps do not warrant double-checking when there are new discoveries out there to be made.

P values are fickle friends

However, we have used simple models to show that the P value often varies dramatically if a study is replicated. Our models depict a simple scenario. Samples have been measured from two conditions. A statistical test called a t-test is conducted to investigate whether there is good evidence that the conditions are different, and the test result is interpreted by the generation of a P value.

The two conditions in our scenario are indeed somewhat different and so we might expect a reasonable sample size to uncover this difference. That is, a reasonable sample size will return a low P value associated with the t-test. However, when we repeat the model experiment many times over, we find that the P value varies dramatically each time.

If your friend has invited you round for dinner next week but in the preceding days keeps contacting you and giving dramatically differing arrival times, you will soon conclude you have very little idea of what time dinner will actually be. Similarly, if P varies considerably each time an experiment is conducted, this makes the P value unreliable, and a poor measure of how strong the evidence is from a single run of that experiment.

The implication is huge for data analysis –- a low P value returned from a study is likely to have as much to do with luck as it has to do with the presence of an important pattern in the data, and in turn a re-run of the experiment might well result in a very different P value. Therefore, a low P value for a single experiment cannot be taken as good evidence that there is a difference between the conditions.

This weakness could well explain why famous scientific findings from the past, central to the foundations of many disciplines, are not being confirmed now that the original studies are finally being re-examined.

These include a lack of reproducibility in cancer research, as well as the apparent loss of the phenomenon called “verbal over-shadowing” whereby people shown a face and asked to describe it are less likely to recognise the face later on than if they had simply looked at it.

Late again! Like an unreliable friend, the P value doesn’t deliver the goods every time. Sfio Cracho/Shutterstock

So why is the P value so variable, so fickle? Unfortunately it seems that some degree of variability between the samples for each occurrence of an experiment creates an unstable P value.

Moving on

So if not the P value, what should we use to analyse and interpret our data? We argue for a fundamental shift in thinking away from asking the question “is there a difference?” and towards asking “how big is the difference?”. After all, scientists rarely want to know simply whether there is a difference between conditions.

There is always a difference, even if extremely small. It is more pertinent to ask whether the difference is big enough to be of interest, to be of importance. If the effectiveness of the red pill is just 0.01% greater than that of the blue pill, there is a difference between them but it isn’t noteworthy – in practice one pill colour is as good as the other.

The P value can be ditched and scientists can focus instead on how big the difference is between the conditions according to their experiment. They can also provide simple-to-calculate values on how precise that difference is likely to be when generalised beyond the laboratory.

Thus once data collection has finished, scientists should focus on estimating how big the difference is in the effectiveness of the blue and red pills, and how precise this estimate is likely to be. Researchers already know about these simple concepts – effect sizes and confidence intervals – they just need to start emphasising them, and let the P value become a thing of the past.

Unfortunately, while a smattering of journals have now started to outlaw the P value in recognition of some of its failings, recently at least one journal has also banned the use of the confidence interval, apparently because its precise statistical definition risks it being over-interpreted and misunderstood.

A reasonable counter to this point of view is that confidence intervals are a valuable tool for estimating the margin of error around our findings – they are a crucial measure when translating our sample of data collected in the laboratory into an understanding of real world scenarios, where results really matter.

Apple may have arrived late to the party, but with Watch it's brought a gun to a swordfight

It's arrived: Tim Cook's watch of many colours. Kay Nietfeld/EPA

While all eyes and ears were trained on news of its smartwatch, Apple also used its spring Keynote to introduce changes to Apple TV, revisions to its laptop lineup, and a new service that builds on the health monitoring aspects of smartwatches to perform data collection for medical research.

As one digital TV service after another launches many have been left wondering when HBO, whose television dramas are highly sought and widely watched properties, would play its hand. And here it is: a partnership with Apple that makes the entire HBO back catalogue available through the new HBO Go digital streaming service, available exclusively through Apple TV. So while the Apple TV hardware hasn’t been updated for years, the partnership with HBO (and a price drop to £59) is a nice reminder for those who may have overlooked it.

Apple has extended its reach into car dashboards with CarPlay, into home automation with HomeKit, and into health monitoring with HealthKit. Apple hopes that ResearchKit, a new open-source API and service, will form the foundation for apps that can collect health data from larger numbers of volunteers, increasing sample sizes and frequency of data collection, making the data more useful for researchers. Five apps have been developed so far, to investigate Parkinson’s Disease, asthma, diabetes and cardiovascular disease with research groups in leading hospitals. There is an emphasis on privacy, with the user controlling the degree of information that is being shared.

The Macbook Air finally gets updated to a retina display, a faster, more energy efficient processor, and a trackpad that can supply tactile feedback. It is lighter, thinner, has a re-engineered keyboard and somewhat controversially rolls many ports into just one: the USB-C standard port, which will handle HDMI video, external hard drives and other USB peripherals. Inevitably this is going to mean buying another set of cables.

The new Macbook Air with shiny retina screen. Kay Nietfeld/EPA

Watch my watch

In any other keynote this reveal would have been the main news item. But of course the main event was the watch. Seven months since Tim Cook first revealed the device, it’s been a long wait for more technical details. Opinion is still split on whether it will be a hard sell. With fewer people wearing watches anyway, the market is split between those who want a fitness tracker and those that want a beautiful luxury object. Is there a need for a device which essentially duplicates the functionality of a smartphone? Apple has to convince us that the watch offers more, in clear terms of where glancing at a watch is preferred to pulling out a phone.

Usually reserved to only one or two colours, this time Apple offers 20 different combinations of ways to customise the watch in size, colour, watch and strap material – probably a necessity in order to sell a device that by nature of being frequently visible is more fashion than function.

One watch to rule them (but in many colours). Martyn Landi/PA

The styling of the watch itself is reminiscent of the first iPhone, with three versions in two different sizes, 38mm or 42mm high: the cheapest Apple Sport at £299 with an aluminium body and plastic straps, the middle tier Apple Watch from £479 in stainless steel and wrist bands in leather, steel or plastic, and the gold Apple Watch Edition, which starts at £8,000 – perhaps more expensive even than the Apple Lisa from 1983, which sold at US$15,000 at the time. All the information, but smaller and nearer. Apple

Most of the functionality of the watch requires an iPhone within a few metres – maps, messages, Siri and other apps are relayed from the phone using WiFi or mobile data. Apple suggests that the battery will last 18 hours in a typical day.

Not first to market, but best?

Apple invests heavily in research and development to create new devices and interfaces that differentiate its products, at least, until competitors release their responses. Apple’s watch uses an Ion-X glass or Sapphire crystal screen which is pressure-sensitive to varying degrees. The side-mounted dial, which Apple terms a digital crown, enables scrolling and clicking, and a button below it jumps to frequent contacts. It has a “Taptic” engine which provides vibration feedback for certain apps, for example suggesting directions in Maps. The sensors on watch’s underside detect heartbeat and combine with the accelerometer to measure physical activity, something Apple is pitching as a major selling point.

Developers are already creating software that will extend their iPhone apps to interact with and be accessible from the watch, as Apple has with its Apple Pay contactless payment system. Miniature messages appear on the device in what Apple calls Glances, giving the impression of dealing with such messages quickly without the hassle of pulling out a phone.

From watches to smartwatches, with only a little relief. XKCD, CC BY-NC

Will it sell? In the past 18 months customers have bought 5m smartwatches or fitness bands, with Samsung flooding the market with many smartwatch devices, but with fitness bands accounting for the majority of sales. Current estimates suggest that Apple could sell more than 8m watches, eight times as many as its largest competitor.

While many of its features will appear in competitor’s smartwatches in the subsequent years, for the moment the eponymous watch is best in class. To sound a note of caution: like the first generation iPhone, the second generation device will probably be half as deep and run twice as long. You may be unfazed about the risks of being an early adopter, but if the idea of paying another few hundred pounds for the latest model next year isn’t appealing, it may be sensible to wait.

Impulse racing: take the pilots out and solar-powered aircraft get really exciting

From Abu Dhabi, Solar Impulse 2 will travel east to India, China, and across the Pacific. Solar Impulse

An aircraft with a 72-metre wing-span – larger than a Boeing 747 – yet weighing only 2.3 tonnes, the Solar Impulse 2 has set off from Abu Dhabi on an attempt to circumnavigate the globe powered only by the sun.

If the Swiss pilot-entrepreneurs Bertrand Piccard and André Borschberg, who take turns to fly the single-seat aircraft, achieve their objective it will be a remarkable achievement and demonstration of the possibilities of solar power.

A solar-powered aircraft is a huge challenge for which the aircraft’s design must be finely honed by the two key requirements of efficiency and mass. The aircraft is powered by 17,000 solar panels fitted to the wing’s upper surface which charge lithium-ion batteries in order to provide power to the four electric motors driving four-metre propellers.

Set a course for maximum efficiency

While the aircraft’s batteries will be fully charged at take-off, it’s essential that the solar panels can continuously provide the energy required to keep the aircraft airborne. This is complicated as the amount of energy that the panels can convert is dependent on the weather conditions, the angle of the sun in the sky, and of course whether it’s day or night. So with ideal conditions the solar panels must generate an energy surplus in order power the aircraft and keep the batteries charged in order to keep the aircraft airborne during less ideal conditions or nighttime hours. Simply put, Without direct sunlight to provide energy, the system has to be tuned for maximum energy conservation in order not to fall out of the sky.

Efficiency is therefore critical in ensuring that the aircraft can eke out every joule of stored energy: components such as the electric motors, at the heart of the system, must be extremely efficient, so that no watt of power is wasted. This can be achieved by selecting an optimum motor design built with the best materials. Key materials include very powerful permanent magnets, which enable the motor to produce the torque it needs to turn. Also the specialist electrical steels that form the core of the motor which are extremely thin and offer very low electrical losses.

Weight loss for aircraft

It also tends to be the case that a heavy electric motor is the most efficient – so weight management is a real problem for a project such as this. Every kilogramme of mass added to a motor must be carried into the air by the airframe. To carry a larger mass the airframe must be heavier and more sturdy which in turn means that the greater overall weight requires more energy to get airborne, demanding larger batteries which add additional weight – an unsustainable increasing spiral.

However, this can be made to work. Perhaps the most impressive example of this technology to date is the Zephyr solar-powered aircraft, developed by UK firm QinetiQ. Powered by motors developed at Newcastle University, in 2010 the pilotless Zephyr broke the record for the longest ever sustained flight of any aircraft, spending two weeks in the air.

Aircraft not just for travel

Zephyr was never designed to carry a pilot, but instead act as a replacement for satellites. Fleets of aircraft such as these could stay aloft indefinitely at altitudes of 50,000-70,000ft, beyond the reach of commercial airliners. They could offer all the communications and relay services currently provided by satellites but at a fraction of the cost required to build a space-worthy vehicle and carry it into orbit.

Being closer to Earth – flying at altitudes of 25km compared to 36,000km for a geostationary satellite – generates lower losses in communication signals. This offers the possibility of low-cost, extremely high-speed communications, with no need for satellite dishes and large transmitters, and without the need for expensive infrastructure such as mobile phone towers and fibre-optic cables.

Looking at it from this perspective, perhaps the biggest weakness of Solar Impulse 2 is the project’s goal of carrying two people around the world. The human crew are heavy and they need to sleep, eat and drink. They are the limiting factors, not the aircraft’s technology.

While the conversion efficiency of solar panels is steadily improving, and their cost has plunged in recent years, the idea of solar-powered replacements for our fleets of airliners is perhaps fantasy. But the prospect of autonomous, pilotless aircraft with limitless range presents all sorts of opportunities and possibilities for the future.