The University of Sheffield's Chemistry News Team
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Resonance Issue 7 | Autumn 2017 The University of Sheffield’s Chemistry News Team The Magical World of Chemistry The Golden Age of Poison The Hidden Detective Resonance The University of Sheffield’s Chemistry News Team Resonance is a biannual newsletter produced by chemistry Editor Resonance Beth Crowston students at the University of Sheffield. It aims to provide insights into unheard stories from the Department and to engage you with issues in the wider scientific world. Design Editor Joseph Clarke Social Media Coordinator Editorial Helen Elmes Resonance is now well into its 3rd year of existence and this is its 7th issue. It may have had a Contributing Authors few facelifts over time, as new editors put their own stamp on it, but at its core it still encompasses all of Joseph Clarke its original values. Beth Crowston Jasmine Cotton When they created Resonance, Alex Stockham and Prof. Simon Jones Greg Coppack wanted to use it as a platform to encourage communication between Rachel Mowll people both inside and outside of the department. They wanted to bridge Zoe Smallwood the boundaries between peer groups and to engage people’s curiosity. As Matt Watson editor for the past two issues, I am proud to say that I have contributed to this vision by taking Resonance to Nanjing, allowing our colleagues over t 5,000 miles away to be involved. This new issue hosts a wealth of interesting articles as many new Copy Editors (and seasoned) contributors share their insights into stories from the department and the wider scientific community. Zoe Smallwood Joseph Clarke finally reveals where lecture theatres 2-5 have disappeared to in the Beth Crowston final installment of the history of the department (pages 5-6); Jasmine Dr Grant Hill Cotton assesses whether Harry Potter is a wizard or actually just a Dr Anthony J. H. M. Meijer budding chemist (page 3); and Greg Coppack addresses the question “Is it possible to study and work in science while maintaining one’s faith?” (page 7). This issue is my last as Editor and I just wanted to thank everybody who has been involved. I especially want to thank Joe Clarke for his continued Email enthusiasm and support. He is the real protagonist in this story; [email protected] undertaking the roles of graphic designer, co-editor and photographer! I’ve enjoyed my time at the helm (I would never have had the opportunity to meet a Nobel Prize winner and an astronaut otherwise), but I am now pleased to pass the baton on to the next generation of editors, Josh Nicks and James Shipp, and look forward to seeing their Printers unique input into the legacy of Resonance. Print and Design Solutions Bolsover Street Happy reading. Sheffield S3 7NA Beth Crowston Contents On the Cover In This Issue Editorial 1 3 The Magical World of Chemistry 3 The Golden Age of Poison 4 The History of the Department 5-6 The Magical World of Chemistry Elemental Factfile: Iridium 6 Can chemistry explain some of the magical objects and spells of the Harry Potter universe? Science and Faith 7 An Interview with Charles Stirling 8 News from the Department 9-12 The Hidden Detective: 13-14 4 How Chemistry Catches Criminals Chocolate: Beneath the Wrapper 15-16 Chemistry Funpage 17 The Golden Age of Poison Poison is a common implement of murder in novels. One particular case in “Mysterious Affair at Styles” demonstrates Agatha Christie’s prowess for writing Get in Touch plausible fictional murders. @resonancenews @SheffieldChem @sheffield.chem 13 The University of Sheffield Chemistry Alumni @Resonance_Sheff The Hidden Detective: [email protected] How Chemistry Helps Catch Criminals The chemistry of luminol can assist in the detection of blood. This and other scientific methods are employed to www catch criminals, even performed by Sherlock Holmes. http://bit.ly/2weV7M1 The University of Sheffield || Resonance Issue 7 2 Feature The Magical World of Chemistry By Jasmine Cotton he wizarding world of Harry Potter has inspired a generation to read and appreciate Tliterature. However, personally I believe that the series also inspired a generation of budding chemists. There are three main aspects in the wizarding world that and organic; most white inks contain titanium dioxide as can be explained by chemistry, these are: coloured fires, the pigment, other inorganic materials such as clays are flames and sparks; special inks; transformations. used as fillers or extenders. The closest Muggle example to the Marauder’s Map is invisible ink. Although invisible There are many mentions of coloured fires or flames in the upon writing, the ink can be visualised using chemical Harry Potter series: reactions, or physical changes. One of the most common invisible inks is lemon juice. This is not initially visible to “... dragons comprised entirely of green and gold sparks the naked eye, due to its composition of sugar, water, and were soaring up and down the corridors […] shocking- citric acid. However, once the paper with the lemon juice pink Catherine wheels five feet in diameter were whizzing applied to it is heated, the writing can become visible. This lethally through the air” is due to the citric acid. In paper, the cellulose fibres can be On the other hand, the fireworks created by mere Muggles degraded by citric acid – the glucose units in the cellulose can easily be explained. In fireworks, the colours are chains are broken down by hydrogen ions, leaving one side produced by heating metal salts that emit characteristic of the unit stable and the other able to bind with a water colours. For example, an orange coloured firework could molecule. This is a cycle that repeatedly weakens the fibres be due to the presence of the metal salt calcium chloride. in the paper, allowing the paper to burn faster and with more ease. Thus, the section of paper with the lemon juice The metal salts emit their characteristic colours because applied will burn faster than the rest of the paper, and show the atoms of each element absorb energy and release it as the invisible ink message. light of specific colours. The amount of energy each atom absorbs is specific to each element, hence the light emitted The last example of the chemical links in Harry Potter are is specific to each element. Using the two equations: transformations: E=hν and c= νλ, (E is the energy, h is Plancks constant, ν is “Goyle’s potion exploded, showering the whole class. the frequency, c is the speed of light and λ is the wavelength) People shrieked as splashes of the Swelling Solution hit it is possible to work out the wavelength of light, and then them. Malfoy got a faceful and his nose began to swell like thus determine the colour of light that will be emitted. a balloon.” Ink chemistry appears many times during the Harry One of the most famous chemistry experiments is Potter series. One of the most famous appearances is the elephant’s toothpaste. The basic idea behind this is that Marauder’s Map, which only allows the user to see the concentrated hydrogen peroxide will break down rapidly, writing once it is activated with the correct words: due to the addition of a catalyst (potassium iodide, etc), into oxygen and water. The addition of soap to the reaction “He took out his wand, touched the parchment lightly, and will cause the creation of foam, as the soap reacts with the said, “I solemnly swear that I am up to no good”. At once, water. As the peroxide decomposition occurs, this creates thin ink lines began to spread like a spider’s web from the a high volume of oxygen that gushes out of the container. point that George’s wand had touched. [...] then words This oxygen pushes the foam out of the container, resulting began to blossom” in a large quantity of foam being released. Sadly, in the Muggle world ink doesn’t appear at the touch of a wand, however, it is still rather interesting. In a chemist’s These are just three examples of the many in the Hogwarts view, ink is a colloidal system of fine pigment particles world which show that Harry Potter is really just a chemist dispersed in a solvent. Ink pigments are both inorganic in training, using simple chemistry reactions or principles. 3 Resonance Issue 7 || Autumn 2017 Feature The Golden Age of Poison By Jasmine Cotton oison has long been a murder weapon of choice, both fictionally and in real life. There seems to be a morbid fascination surrounding the use of poison, one which has led to several murder mystery Pbooks adopting it as the murder weapon. But do they depict it accurately? One of the great murder mystery authors was Agatha effect; the reduction in the solubility of an ionic precipitate Christie. Across more than 80 detective novels, she when a soluble compound containing one of the ions of the has killed off over 300 people, and at least 100 of those precipitate is added to the solution. This effect can be seen: were murdered using poison. Christie uses a vast range a solution of strychnine sulphate in water is completely of poisons in her detective novels, the chemistry behind clear, but after addition of potassium bromide, crystals of which is more often than not accurate in its description. strychnine bromide precipitate, see Figure 1. The accuracy behind Christie’s chemistry can be traced back to her volunteer efforts during the First World War. At first, she volunteered as a nurse in Torquay, but later she was offered the chance to work in a pharmacy as a dispenser.