From the bestselling author of Stuff Matters comes a fascinating tour of the world of these surprising and sometimes sinister liquids - the droplets, heartbeats and ocean waves we encounter day-to-day. Structured around a plane journey that sees encounters with water, wine and oil, among others, Miodownik shows that liquids can be agents of death and destruction as well as substances of wonder and fascination. Read below an exclusive extract from Liquid.
As soon as the aircraft doors closed, and we pushed back from the gate at Heathrow Airport, a voice announced the beginning of the pre-flight safety briefing.
‘Good afternoon, ladies and gentlemen, and welcome to this British Airways flight to San Francisco. Before our departure, may we have your attention while the cabin crew point out the safety features aboard this aeroplane.’
I always find this a disconcerting way to start a flight. I am convinced that it’s a fake: that the safety briefing isn’t really about safety at all. For a start, they fail to mention the tens of thousands of litres of aviation fuel on board. It is the enormous amount of energy contained in this liquid that allows us to fly at all; its fiery nature is what powers the jet engines so that they’re capable of taking, in our case, 400 passengers in a 250-ton aircraft from a standing start on the runway to a cruising speed of 500 mph, and to a height of 40,000 feet, in a matter of minutes. The sheer awesome power of this liquid fuels our wildest dreams. It allows us to soar above the clouds and travel anywhere in the world in a matter of hours. It’s the same stuff that took the first astronaut, Yuri Gagarin, into space in his rocket, and that fuels the latest generation of SpaceX rockets, which fire satellites into the atmosphere. It is called kerosene.
Kerosene is a transparent, colourless fluid that, confusingly, looks exactly like water. So where is all that hidden energy stored, all that hidden power? Why doesn’t the storage of all that raw energy inside the liquid make it appear, well, more syrupy and dangerous? And why is it not mentioned in the pre-flight safety briefing?
If you were to zoom in and have a look at kerosene on the atomic scale, you would see that its structure is like spaghetti. The backbone of each strand is made of carbon atoms, with each one bonded to the next. Every carbon is attached to two hydrogen atoms, except at the ends of the molecule, which have three hydrogen atoms. At this scale you can easily tell the difference between kerosene and water. In water there isn’t a spaghetti structure, but rather a chaotic jumble of small V- shaped molecules (one oxygen atom attached to two hydrogen atoms, H2 O). No, at this scale kerosene more closely resembles olive oil, which is also comprised of carbon-based molecules all jumbled up together. But where the strands in kerosene are more like spaghetti, in olive oil they’re branched and twirled. Because the molecules in olive oil are a more complex shape than the ones in kerosene, it’s harder for them to wiggle past each other, and so the liquid flows less easily – in other words, olive oil is more viscous than kerosene. They’re both oils, and on an atomic level they look relatively similar, but, because of their structural differences, olive oil is gloopy while kerosene pours more like water. This difference doesn’t just determine how viscous these oils are, but also how flammable.
A Financial Times Master of Science and chosen by The Times as one of the 100 most influential scientists in the UK, Mark Miodownik is Professor of Materials and Society at University College London, where he is also Director of the Institute of Making. He is the author of the book Stuff Matters, a New York Times bestseller which won the Royal Society Winton Prize. Mark has also received the Michael Faraday Prize for his expertise in science communication. He presents BBC TV and Radio programmes on science and engineering such as Everyday Miracles, How It Works, Chefs vs Science, Secrets of the Super Elements and recently made a three-part BBC Radio 4 documentary called Plastic Fantastic.