Now I don’t know about you, but the thought of jumping from that height into a pool of water fills me with dread. Fortunately, researchers at Cornell and West Chester universities in the US, led by Sunghwan Jung, have just released some advice in the journal Science Advances for anyone foolish enough to plunge from that height.
By dropping 3D printed models of a near life-sized human torso, connected to a force sensor, into a tank of water, they conclude that – without any training – you’re likely to injure your spine and neck if you dive head-first from a height of more than 8 metres into water. Plunge in hands-first from above 12 metres and you’ll probably knacker your collarbone, while you’re likely to damage your knees if you just jump in feet-first from above 15 metres. You have been warned.
Power when you need it
Now if you’re off on holiday, there’s nothing more annoying than discovering your phone’s battery has died – just when you need to capture that Instagram-perfect sunset or show your online boarding pass to an impatient security guard. I can therefore see an obvious market for a new water-activated disposable battery devised by Gustav Nyström and colleagues at the Swiss Federal Laboratories for Materials Science and Technology (Empa) in Dübendorf.
It consists of a rectangular strip of paper with an ink of graphite flakes on one side acting as the cathode and a zinc powder printed on the other as the anode. As they explain in a paper in Scientific Reports, both sides are covered with another layer of graphite flakes and carbon black, which connects the anode and cathode to two wires at one end of the paper.
What’s clever is that the paper has salt (sodium chloride) dispersed throughout it. So if you add a bit of water, the salts dissolve, releasing ions that activate the battery. The authors combined two of these cells into one battery and used it to power an alarm clock with a liquid-crystal display.
Tests show that just two drops of water can activate the battery within 20 seconds, providing a healthy 1.2 volts. That value falls away sharply as the paper dries but adding two more drops will perk it back up to 0.5 V for an additional hour.
That’s probably not enough for a mobile phone: the authors say their battery is, in fact, more suited for “smart labels” for tracking objects, environmental sensors and medical diagnostic devices. Still, one can dream.
Teangannan na Gàidhlig (Gaelic tongues)
And finally, if you’re on vacation on the Isle of Lewis off the west coast of Scotland and have no idea what people are saying to you, help is at hand.
That’s because researchers at Lancaster University have videoed people’s tongues while they spoke Gaelic and Western-Isles English to investigate what kinds of movements are used to produce different consonants.
Using ultrasound, they then obtained a profile image of the tongue inside the mouth as the speaking took place. You can watch some of the videos on the Seeing Speech website, created by speech and language experts at the University of Glasgow and Queen Margaret University in Edinburgh. If it helps, here’s someone saying “beer”.