The basic technology of military and naval artillery has changed little since the introduction of gunpowder in the Middle Ages. Today’s large guns still use explosive chemicals such as gunpowder to fire a projectile down a metal barrel.
But the US Navy is developing a different type of weapon, based on pulses of electrical rather than chemical energy. The “electromagnetic railgun” can blast shells at 5,000mph – seven times the speed of sound – with a potential range of 100 miles.
Last month, the railgun took a big step from research toward production, as the navy started testing the first prototype weapon produced by an industrial contractor. The Office of Naval Research has released a spectacular video of the gun – made by the US subsidiary of Britain’s BAE Systems – firing at its Dahlgren testing centre in Virginia. Evaluation of a second prototype, built by General Atomics of the US, will begin next month.
“Unlike the laboratory launcher, this railgun has the look and design of a gun that could potentially fit onboard a surface ship,” said Amir Chaboki, BAE programme manager for advanced systems. “These tests will complete the first phase of a two-phase programme to essentially invent an entirely new gun that will change the [US] Navy forever.”
The railgun uses the magnetic field generated by strong electrical currents to accelerate a metal conductor, sliding between two rails, to hypersonic speed. This discharges a shell two to three times faster than any gun based on chemical explosives.
The electrical energy used to fire a railgun is huge. The BAE prototype is a 32-megajoule machine – equivalent to the kinetic energy of a 32-tonne lorry driving at 100mph. So its projectile would deliver a devastating blow, even if it was a solid metal shell rather than a device that explodes on impact.
Although designs for something like an electromagnetic railgun date back to the first world war, the materials and power supplies were not strong enough to make a working model. More serious research was carried out during the 1980s and 1990s by defence engineers in the US and UK – and smaller-scale predecessors of the latest prototypes were tested in Scotland at Dundrennan Range near Kirkcudbright.
The US Office of Naval Research has spent $240m over the past five years and expects to spend a similar sum on industrial development between now and 2017. The expenditure required to actually deploy the new weapons on warships after 2020, in place of the navy’s conventional 5in guns, would be vastly greater. Before that decision can be taken, the navy and its contractors will have to address several issues. One is how to generate, store and discharge the huge pulses of energy required to fire the weapon without throwing out the ship’s electrical systems.
To build up the railgun’s firing rate to 10 rounds per minute, as the navy demands, the researchers will have to develop new ways of cooling the weapon between discharges. And the projectiles themselves are likely to include some sort of navigation system to guide them towards their target. This will require electronics that can withstand immense forces of acceleration as the gun fires.
The greater power of the railgun will enable commanders to use it for bombardments beyond the range of today’s naval guns, which cannot reach beyond 15 miles.
But although the railgun may seem novel, there is one old-fashioned thing about the project. The Office of Naval Research has given it a Latin motto: Velocitas Eradico. Or in English: “speed kills”.
The right type of words
If you are choosing a boy’s name for a newborn baby, go for Johnny rather than Freddie. For a girl, Molly is better than Sara. That advice is based on a study showing that words spelled with more letters on the right side of a Qwerty keyboard are associated with more positive emotions than those with letters mainly on the left side.
The authors, Kyle Jasmin of University College London and Daniel Casasanto of The New School for Social Research, New York, claim to find the first link between the meaning of words and the way they are typed – a relationship they call the Qwerty effect. Their study appears in Psychonomic Bulletin & Review.
The researchers discovered that meanings of words in English, Dutch and Spanish were related to the way people would type them on the keyboard. In all three languages, words with more right-side letters were rated more positively in meaning on average than words with more left-side letters.
This effect also applied when people judged the meanings of fictitious words, and was not affected by word length, letter frequency or whether people were left or right handed. It was strongest in words and abbreviations coined after the invention of the Qwerty in the 19th century – and particularly in new words that have come into use since smartphones and personal computers.
Although the study did not test the reasons for the effect, it might reflect a more general sentiment in a predominantly right-handed world that right is better than left.
Eat your way to good looks
Eating more fruit and vegetables can improve your skin colour within a few weeks – and make you look more attractive – according to a study at the University of St Andrews.
Researchers monitored 35 students over six weeks. Increasing fruit and vegetable consumption by three portions per day was enough to change skin colour and tone significantly.
The subjects’ appearance was measured not only by scientific instruments but also by showing their photographs to human observers. The latter rated students who ate more fruit and vegetables as more attractive.
“People who eat more fruit and vegetables have a ‘golden’ skin tone that looks healthy and attractive,” says Ross Whitehead, the study leader. “Even small improvements in diet produce visible benefits to skin colour. We were very surprised by how quick the changes were.”
The St Andrews scientists hope their findings, published in PLoS One and the American Journal of Public Health, will help campaigns to promote healthy eating.
“We hope that highlighting the rapidly achievable benefits of a healthy diet on our attractiveness will be a stronger incentive for people to eat more healthily,” Whitehead adds. “Knowing you are going to look more attractive in a few weeks may be more persuasive than the promise of health benefits later in life.”