How to out-swim an Olympic champion: what makes great white sharks such speedy swimmers?

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Milly Gigg

During July’s annual “Shark Week”, Olympic champion swimmer Michael Phelps went head to head with a Great White shark in a 100 meter race. Fortunately for Phelps the shark was not real, but instead a computer simulated fish created using data on the swimming speed of sharks. Despite being equipped with a wetsuit and a monofin that mimicked a shark’s powerful tail, Phelps swam the race two seconds slower than the shark. Just what exactly makes great white sharks such speedy swimmers?

Whilst Phelps can reach impressive speeds of 6 mph, great white sharks can swim up to 25 mph, potentially 35 mph in small bursts. This makes them the third fastest swimming shark in the world – beaten only by Salmon sharks and Mako sharks, which can swim up to 50mph and 60mph respectively. Explanations for this speed include warm blood temperature, enormous size and a high metabolism, as we will discover.

Firstly, great whites are thought to have a slightly warmer blood temperature than other shark species. Whilst most sharks are cold-blooded, great whites and other species of sharks belonging in the family Lamnidae, for example Mako sharks, are partially warm-blooded. They can be characterized as endotherms, meaning they are capable of generating heat internally. Their ability to do this stems from their special blood vessel alignment, specifically known as rete mirabile. This is a network of capillaries where the heat produced from muscle activity is recycled into colder blood through counter-current exchange.

More specifically, the vessels are arranged in such way that the warm blood coming from the swimming muscles is aligned to the cold blood coming from the gills, meaning heat can be easily transferred. The arteries in the rete mirabile carry oxygenated blood from the gills that have been in close contact with the outside water, decreasing the blood’s temperature. These meet a bundle of veins that are carrying heated de-oxygenated from the organs, and the heat is passed from these veins to the colder arteries. Great whites have these systems in their swimming muscles, brain and stomach, allowing them to increase the temperature of organs in these areas to around 14 degrees above the surrounding water. Therefore, they can inhabit waters that are too cold for other sharks. As blood on the way to be delivered to the swimming muscles is pre-warmed, this keeps their muscles readily powered. As we all know, a warm muscle is better than a cold one when it comes to activity, meaning sharks can swim at high speeds for long periods of time.

Another adaptation for speed held by great whites is their enormous size, which gives them great power. Great whites exhibit significant differences between genders, and the females are significantly larger than the males. On average, males weigh around 522 to 771 kg, with females being around 1950 kg. In fact, the largest individual weighed was an impressive 3,324 kg! Their gigantic size means they have extremely strong tail muscles which they use to power them through water at great speeds. Complementing their size is an extremely streamlined body. The torpedo like shape minimizes drag, whilst their pectoral and dorsal fins mean they can glide seamlessly through the water.

Finally, the great white shark has a high metabolism. Their blood has high levels of hemoglobin, meaning at any given time there is a high amount of oxygen being pumped around the shark. This allows plenty of aerobic metabolism to take place. On top of this, the ventricle of the great white – which is where oxygenated blood is pumped out of the heart to the rest of the body – is well muscled. This allows for lots of oxygenated blood to be pumped around the body at a fast rate. Together, these adaptations mean that oxygen is readily accessible at all times in a great white, allowing for plenty of aerobic respiration and thus a constant, immediate supply of energy. It is this energy that enables great whites to become such speedy swimmers.

Who is Koko the Gorilla?

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Emma Hazzlewood

You may have heard of Koko – the west lowland gorilla who has been taught to “speak” to humans, using American Sign Language (ASL). Koko started learning sign language in 1972, at the age of one. Now 44 years old, Koko knows around 2000 words, ranging from basic objects to emotions. Project Koko, led by Dr Penny Patterson, is the longest uninterrupted study on ape language abilities.  It was started to find out not only about gorillas and their cognitive abilities, but also to investigate what makes language human.

Koko has caught the eye and, in some cases, heart of many celebrities. Her friends include Betty White, Leo Di Caprio, Sting, Peter Gabriel, William Shatner, Mister Rogers and more. She established an especially close bond with late comedian Robin Williams. By the end of their first meeting, Robin and Koko were tickling each other and playing chase.

Many parallels have been found in the way Koko learns sign language with the way a small child learns sign language. However, Koko learns significantly slower and asks fewer questions. As Koko has an IQ which would not suggest she would learn slower, it is believed this may not be because gorillas are less capable of learning sign language, but rather because Koko is obviously not immersed in the same social situations as a human child.

As Dr Patterson teaches Koko the sign language, she also speaks the words aloud. This has allowed Koko to comprehend a lot of spoken English, which often shocks people the first time they meet her. They expect to be able to make comments about Koko to her trainers and are surprised to find that she follows the conversation.

Although Koko’s trainers are convinced she truly understands the words she is using, there are critics who argue that she is just mimicking, as Koko receives a reward when she signs certain words. Many claim that a lot of the data collected from Koko may be due to the Clever Hans effect – when asked a question, Koko may not be understanding and responding to the question, but rather can tell from her trainer that she is supposed to sign “yes”.

In response to these criticisms, Koko’s trainers argue that she is capable of sophisticated sign language, with consistent grammatical structure. Furthermore, Koko has been known to invent new signs for words she has not yet learned by stringing together words she knows, such as “scratch comb” instead of brush.

One aspect of Koko’s personality which has captured many people’s hearts is her love of kittens. For years, Koko tried telling her trainers that she wanted a baby, and used to cuddle toy dolls. Obviously baby gorillas are not easy to come by, so instead the researchers got her kittens. Koko can be seen cuddling her kittens, and consistently asks for them to be put on her head.

It appears that Koko is capable of expressing complex emotions. When Koko’s first kitten, All Ball, was tragically killed by a car, Dr Patterson told Koko. Koko responded by saying she was sad, and her trainers report that she grieved for days afterwards.

Koko communicates feelings in a way that suggests extraordinary emotional depth. She has shown empathy, not only for other gorillas but also for humans. This has philosophical implications, as many would have once said that what makes humans human is that we have complex language and a sense of empathy, but it appears we actually share both of these traits with other primates.

There was a hope that Koko would show the world that gorillas are worth protecting – if they are capable of showing empathy towards us, shouldn’t we in return stop poaching them, and destroying their habitat? However, in the last 20 to 25 years (over 20 years into Project Koko), West lowland gorilla populations have fallen by 60%, largely due to poaching for bush meat.

Koko currently lives at The Gorilla Foundation in California, and was recently given a box of kittens to chose from as a 44th birthday present. She continues to use sign language every day, and has recently started to learn to read. In the future, Dr Patterson hopes that, some day, Koko may have a baby. If she does, the world will be watching to see if Koko can teach her infant sign language.

Black Holes and Gravitational Waves

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Alexander Marks

On the 14th August 2017, the fourth set of gravitational waves were detected. Although the first waves were recorded in early 2016 by LIGO (Laser Interferometer Gravitational-Wave Observation), this time three different observatories detected the gravitational waves. A pair of black holes caused these waves by violently merging together.

Three Scientists at LIGO, Rainer Weiss, Kip Thorne, and Dr Barry Barish have just been awarded the Noble Prize in Physics, for the first detection of gravitational waves and it was these three scientists who designed and ran the two LIGO observatories, situated in Washington and in Louisiana. In the most recent detections a new observatory in Italy called Virgo also measured the same waves.

Why are three detection’s better than two? Three detection’s allow scientists to better pin point the origins of the signals, 20 times more precisely than just two. This is key for follow up observations. It also provides more information about the object that made them, such as the angle they are tilted at compared to Earth.

Gravitational waves where first predicted by Einstein’s theory of relativity back in 1916. This theory was ground breaking and combines space and time to form the space-time continuum. His theory states that any object with mass warps the space-time continuum, the more massive the object the bigger the warp. It is these warps in space-time that cause gravity.

The famous equation of general relativity is incredibly hard to solve, and requires super computers to find solutions. One of the solutions predicts gravitational waves.

Gravitational waves are caused by all objects as they move through the space-time continuum.  Every object makes gravitational waves, meaning that even a tiny snail moving in the grass produces them. They ripple through space-time much like ripples caused by throwing stone in a still pond.  Gravitational waves were the last part of Einstein’s theory to be proven.

The equation predicts that gravitational waves would travel at the speed of light and carry information of the objects causing them. But most of the gravitational waves are too weak to be measured. It requires a massive object to create the large enough ripples in space time to be measured.

Enter black holes and neutron stars. Black holes are the most massive objects in the known universe. Their mass is so large that light cannot escape their gravity. When two black holes orbit very quickly around each other and eventually merge, they create immense distortions in the space-time that can be measured on Earth.

By measuring the gravitational waves and using Einstein’s theory of relativity, scientist can learn a lot about the darkest parts of our universe. Scientists can predict the mass, rotation and how powerful the event was.

Neutron stars are the remains of stars that have collapsed in on themselves, and are also very massive and could theoretically be detected as well. Yet, there has been no detection of gravitational waves caused by them but, there is promise that these will soon be detected as well.

Even the largest ripples in space time are very difficult to measure. LIGO and Virgo are carefully designed to detect these ripples. Each of the observatories is shaped like an L. Each arm of the L is a long tunnel that are vacuum sealed. At the end of each tunnel there is a mirror, and a split mirror where the two meet. (A split mirror can split laser light in two, and send it in different directions).

Lasers are sent down the tunnels at the same time, without the presence of gravitational waves both lasers would return at the same time. When gravitational waves are present the space-time is warped in such a way that one mirror gets closer and the other gets further away. This results in the laser beams returning at different times, allowing scientists to measure the amount the mirrors were warped. This measurement is very small, about 1000 times smaller than a proton.

This means the bigger the gravitational waves the larger the time gap between the lasers returning. As the time gaps are so small, only very massive object can produce waves big enough to be detected.

 

The black holes that created the most recently detected gravitational waves had masses of 25 and 31 times the mass of our sun. They were orbiting each other 1.8 billion light years away and merged into a black hole of 53 times the mass of our sun. This is a supermassive black hole, and is bigger than ever expect to be found.

 

This is the third black hole to be bigger than expected. Black holes of this size appear be more common than originally thought and the rate at which they occur will soon be figured out.

 

The observatories are currently being upgraded and will become even more sensitive. Scientist hope that when they are turned back on in Autumn 2018 they will detect up to ten of these events each year. There is also hope of detecting gravitational waves from neutron stars as well.

 

With observatories planned in Japan and India, it can be expected to find new phenomena occurring in the universe that may have been thought impossible.

Aliens! Hoaxes and conspiracy theories.

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Sophia Akiva

“10 unbelievable real alien encounters!” is not an uncommonly used click-bait topic, attracting the curious and the gullible to questionable advertising sites. Our fascination with the possibility of mysterious extra-terrestrial beings has made us vulnerable to con artists, made us question our governments and worst of all, has even lead Ancient Aliens to take over a formally reputable TV channel. But is there any truth to these stories or are broadcasting stations merely exploiting footage (of conveniently poor quality) in the name of profit?

To begin with, let me honour one the greatest alien conspiracy theories to date, one that kept the world on the edge of its seat long after the initial event. Even now, the Roswell incident continues to serve as inspiration to the media, referenced heavily by believers and critics alike. On many occasions it had been named the most iconic instance of extra-terrestrial encounters yet equally frequently called the most thoroughly debunked hoax. The supposed weather balloon crash occurred in 1947 and was addressed by the Roswell Army Air Field personnel during a press conference, leaving no room for doubts or excitement so the story quickly and quietly faded away. It remained dormant for three decades, when it was awoken by the popularised hobby of spreading conspiracy theories. The believers so adamantly pursued circumstantial evidence and foggy memories from thirty years before that stories began to evolve and grow, fuelling the public’s interest with their concocted details and flexible accounts. Several books were published on the topic of Roswell, some exploring these fabricated tales through an imitation of the scientific method and some who concluded that the evidence presented was simply insufficient and often gathered from unreliable sources. The pressure on the Air Force to declassify the information from 1947 continued to mount until in 1994 they revealed the truth; that a weather balloon was a high-altitude military surveillance balloon used to monitor for evidence of nuclear testing as part of Project Mogul[1].

There have been multiple alien autopsy videos released to the public with evidently varying production budgets despite the increasing availability of special effects software. These videos, that have once entranced nations, have now taken the place of viral jokes, shared between school children and bored office workers. So, what has made us lose our faith? Have we become desensitised to the excitement of possibility or have we at last learned to question what we see before us? It is true that alien autopsies have never been supported by physical evidence and in many instances the creators themselves have stepped forward with confessions of their deceit. Perhaps this crucial data is being withheld by global intelligence agents, hidden away in coded X-files that take such extensive funding to maintain as to leave the less valuable military and economic information vulnerable to hackers and leaks.

Another famous, but very short lived, alien hoax was the accidental country-wide panic caused by the broadcast of The War of The Worlds on Halloween of 1938. Orson Welles and the Mercury Theatre team created a sensational contemporary adaptation of H.G. Wells’ novel that was done a little too well. Initially, the team had little hope of success with this project and had it not been for some major last-minute rewriting, the show would have been nothing more than a pleasant hour for some few dedicated fans. However, due to problems with scheduling, the show was unintentionally timed more as a genuine news broadcast. This, combined with the brilliant efforts of the actors and sound technicians quickly caused widespread fear among the listeners who tuned in too late to hear the introduction explaining the adaptation of the 19th century novel. It is generally believed that the chaos caused by the realistic reports of Martians rapidly invading the Earth was unintended but as with many alien hoaxes, it sure worked in favour of the creators’ careers.

To say that all current evidence for visitations from extra-terrestrial beings is comprised of hoaxes and conspiracy theories does mean that there is no hope of intelligent civilisations sharing this universe with us. We have reached out with the Voyager golden record that contains images and sounds from Earth as well as diagrams and equations expressing our current understanding of mathematics and laws of physics. Unfortunately, it will be far in the distant future that an alien race may receive this little guide to life on Earth. For decades now, we have been listening out for a message from beyond. One promising sign came in 1977, when a researcher at Ohio State observatory was so amazed by a strong radio transmission that he wrote “Wow!” in the margin, coining the instance as the Wow! Signal. The possibility of this being evidence of alien communication has lingered on the minds of astronomers for decades, but in all this time we have not heard from them again. The frequency of this transmission corresponds to hydrogen, so although it was highly unusual, it can possibly be explained by continued development of our astronomical understanding. Be it intelligent aliens or physics that we have not yet discovered, the truth is, and will always be, out there.

[1] http://muller.lbl.gov/teaching/physics10/Roswell/USMogulReport.html

One ticket for the Enterprise please! Has China successfully created an sustainable EM Drive?

 

320x240Shannon Greaves

Space is awesome. So awesome that it has had the global powers stuck in a space race even before America took that one giant leap for mankind. Everyone is eager to explore new planets, solar systems and travel faster than light (FTL) with their very own warp drive Enterprise. Well to all us astronauts at heart, that day may be coming sooner than later, now that China has released a video claiming not only to have a working EM drive, but also are claiming to have one already in space on their space laboratory ‘Tiangong-2’! Prior to this news of success from China, China was reported to have only been studying the EM drive, with no reports of successful functionality. Furthermore, both the UK and NASA have also been working on creating an EM drive, with a mixture of breakthroughs and problems. But before we get into the thick of things, let us have a quick review on some important information about the EM Drive.

The Electromagnetic drive (EM Drive), scientifically known as a radio frequency resonant cavity thruster, makes use of microwaves and particles that are bounced around inside an asymmetrical-shaped cavity, which produces thrust with an increasing momentum. Much like to if you were in a box, pushed on the side, and started to move with acceleration. What this means simply is that an EM drive creates thrust without the need for a propellant. Sadly, what an EM Drive isn’t is a warp drive as seen in Star Trek. Unlike how the EM Drive creates thrust, a warp drive appears to enable FTL travel through warping the fabric of space and time around a ship, allowing it to travel less distance.

Still, a working EM Drive would mean a whole bunch of good things for us, including a much faster way of travelling through space (just maybe not FTL Level). A fully functional EM drive would mean there would be no need for heavy propellants such as rocket fuel on board, and would result in a trip to mars only taking between 70-72 days, compared to the average of 270 days it takes us today. What’s even more impressive, is that according to NASA, with an EM drive it would only take us 92 years to travel to our nearest solar system! In addition to faster space travel, the EM drive would result in: cheaper space travel, solar power stations with cheap solar-harvesting satellites that could beam power back to earth, and generally provide us with a greener and convenient energy source for travel.

So, what are we waiting for!? Well before you go buy your space suits and tickets to China, there is a lot of discussion on whether China’s claims and experiments with the EM Drive are true. So far, all China has given us is a press conference announcement and a government sponsored Chinese newspaper (and China doesn’t have the best record of accomplishment for trustworthy research). Within the press conference they also claimed to need to do further experiments to try to increase the amount of thrust being produced. What we need is a peer-reviewed paper, which would not only provide conclusive evidence for their results with the EM Drive, but also confirm the reliability of their claims to testing it in space. China does have some stability to their claims however, with China claiming to have produced similar results to that of the work of NASA’s EM Drive experiments. NASA’s has been working equally as hard on the EM Drive, and have produced several models of EM Drives producing Thrust. They even finally managed to publish a peer review paper, with an EM Drive producing small amounts of Thrust within a vacuum. This gives a little backup to China’s claim of an EM Drive in space.

The biggest problem the EM Drive faces is that arguably its biggest contribution to science today is also its biggest problem and why many experts contest against it. The very physics of the EM Drive not requiring a propellant violates Newton’s third Law of Motion, “for every action there is an equal and opposite re-action”. So, on the one hand, where this would mean that the EM Drive would change the basis of how we understand physics, it also means that no one can explain how it works. Without this explanation, the consensus is that we can’t possibly use and sustain the EM Drive.

So, what happens now? Well we are going to have to wait to see if China releases that peer review paper, but even without that we have made a lot of development in our goal to space travel. The combined effort of China, NASA and other national institutions have brought the EM drive closer out of the theoretical, and into the possible. There has even been some theories created to explain how the EM Drive works, “quantised inertia” being responsible for creating this thrust. If true, this would mean that the EM Drive would not completely violate the conservation of motion, but adapt it. If you’re interested in the applications of “quantised inertia” to the EM Drive, then consider the works of Dr Mike McCullock. Furthermore, for those of you wanting that FTL warp drive, then there is some hope! NASA engineers have been reporting on forums that when they fired lasers into the EM Drive’s resonance chamber. The result was that some of the beams traveled faster than the speed of light. This suggests that the EM Drive may have the capacity to produce the needed “warp bubbles” for a warp drive! Nasa has even been designing a warp drive ship if you want to check that out to! Now, I’m off to watch some Star Trek, but keep an out for the announcement of a reality tv version!

Regaining signs of consciousness after 15 years in a vegetative state!

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Emma Hazelwood.

A man in France has regained some signs of consciousness after being in a vegetative state for fifteen years.

A vegetative state is defined as the absence of responsiveness and awareness due to brain damage, although some motor reflexes are maintained as normal. The issue of consciousness has baffled humans for centuries – there is no one test to determine whether someone is conscious. Instead, there is a scale known as the Coma Recovery Scale, which looks at various aspects of consciousness (including communication and auditory and visual functions).

The 35-year-old went into a coma after being involved in a car accident in 2001, and had shown no signs of improvement since. That is, until scientists tried a new treatment, involving using electricity to stimulate a nerve in the man’s body, known as the vagus nerve. This nerve runs from the brain to several areas of the body, including areas involved in emotion, alertness and memories. It was thought that after this treatment the patient may be able to regain some consciousness, without the risk of side effects from medication.

Improvements in the subject’s condition could be seen within a month of treatment. At first, this just meant being able to open his eyes more often. His brain showed activity in areas which had previously been quiet, and eventually he was able to follow an object around the room with his eyes, and even respond to requests to turn his head from one side to the other. He reacted with surprise when the examiner’s head suddenly approached his face. Amazingly, he shed tears and could smile with the left side of his face when he was played his favourite music.

According to medical professionals, this is known as a “minimally conscious state” – the man has not fully regained consciousness to the extent he had before the accident, but he is able to show some self and environmental awareness.

Although the test needs to be repeated in other patients, the results have neurologists very excited for future potential treatments involving this technique.

However, this experiment further demonstrates how little we know about consciousness, and brings into question the ethics surrounding treatment of people in vegetative states. Recently, the Court of Protection in England and Wales ruled that if doctors agree it is in the patient’s best interests, families of people in vegetative states no longer need the court’s permission to let their loved one die.

We do not have a perfect way of deciding whether someone is conscious or not. A 2010 study by the New England Journal of Medicine found that 40% of patients who had been assumed to be completely vegetative were actually able to communicate, even if it was just through yes or no questions.

If someone can “wake up” after fifteen years of no environmental awareness, this may complicate the already complex issue of whether it is right to decide to stop artificially feeding people in vegetative states. This could add to the guilt and emotional distress of families trying to decide whether or not to keep their loved one alive through machines, not knowing whether or not they are in pain or will ever wake up; or letting them die, never knowing whether they would have recovered.

The process may also be emotionally distressing for the patient. In this example, doctors have not yet asked the man whether he is in pain. Furthermore, doctors agree that he has such severe brain damage that it is unlikely he will ever be able to walk or talk again – even if he is eventually able to fully regain consciousness. This brings into light concerns around whether it is right to bring back someone who has been unconscious for so long (so many things have changed since he went into a coma in 2001), and to a lower quality of life than before, especially when we do not fully understand the process.

This treatment has been a breakthrough discovery for neurologists, and opens up a new world of possible treatments. However, it is essential that as we discover more about consciousness and how it is regained, we continue to consider the ethical consequences of our actions.

 

Poison or Peaches?

cyanide-apple-featureChlo McCole

Murder mysteries often feature cyanide as a poison, but did you know you can be exposed to this toxin in everyday life too? Have you ever wondered how cyanide poisons and kills people, how much it takes before its toxic, and whether there is a cure? Here’s what you need to know.

Cyanide is the CN ion (one carbon atom bonded to a nitrogen atom) and as a poison it is commonly administered as one of three compounds: hydrogen cyanide, a volatile, colourless liquid, and potassium and sodium cyanide, both white powders. Both potassium and sodium cyanide react with stomach acid to produce hydrogen cyanide, which can then go on to cause toxic effects.

Though cyanide has been used as a poison for centuries, it was first isolated in Sweden in 1782, by Swedish chemist Carl Scheele. Whilst different sources tell different stories, some claim that his exposure to cyanide was a contributing cause to Scheele’s death at the age of 43. He was also the first person to note the bitter almond smell of hydrogen cyanide – a smell which, it turns out, can only be detected by 40% of people for genetic reasons.

So, what happens when a person is poisoned with cyanide? Upon ingestion, cyanide binds to haemoglobin, the molecule in red blood cells responsible for carrying oxygen to the cells in our body. Haemoglobin then ferries it to the body’s tissues, where it can bind to an enzyme called cytochrome oxidase. This enzyme is a vital tool which cells require to make energy and with cyanide bound to it, they are unable to do so. It’s a bit like using treacle instead of petrol in your car; both fit in the tank but treacle will just clog the system.

The symptoms of cyanide exposure include headaches, nausea, vomiting, and elevated breathing and heart rates. With a high enough dose, these symptoms quickly progress to loss of consciousness, respiratory failure, and death.

How much cyanide is fatal depends on the route of exposure, the dose, and duration of exposure. Inhaled cyanide presents the greatest risk, followed by ingestion. Skin contact is not as much of a concern (unless it has been mixed with DMSO). A fatal dose for humans can be as low as 1.5 mg/kg body weight.

Cyanide is actually a relatively common toxin in the environment, and because of this the body can detoxify a small amount of cyanide. For example, you can eat the seeds of an apple, bite into a peach stone or smoke a cigarette without dying.

Perhaps the most well-known use of cyanide as a poison was in the Nazi concentration camps of World War II. There, the Nazis used Zyklon B, a cyanide-based pesticide to kill millions. Cyanide was also involved later in the war; though it’s commonly thought that Hitler committed suicide by shooting himself in the head, evidence has suggested that he in fact killed himself using a pill containing potassium cyanide, along with his wife of just 2 days, Eva Braun.

Cyanide poisoning is still a not-uncommon occurrence, though the exposure is often accidental. In particular, plastics such as nylon and polyurethanes release cyanide when burnt, so during fires cyanide poisoning can often occur. In the Grenfell Tower Fire of 2017 a number of the deaths were thought to be as a result of the inhalation of cyanide and other toxic gases produced by burning plastics.

As cyanide is such a fast-acting poison, it can be hard to administer any antidote in time. Thiosulfates are commonly administered in combination with nitrites, as they help convert the cyanide to thiocyanate, which can then be eliminated in urine. Vitamin B12a has also been used, which can bind the cyanide to form another harmless form of vitamin B12.

Cyanide poisoning can be detected in a number of ways; the most common is a simple, lab-based test. A tissue sample is added to 5% sodium hydroxide solution, which is in turn added to a solution containing 5% iron (II) sulfate and 1% iron (III) chloride. This is heated to 60˚C for 10 minutes, and then transferred to a solution of hydrochloric acid. The appearance of a blue colouration, caused by the formation of the iron-cyanide complex known as Prussian blue, indicates the presence of cyanide ions in the original sample.

Despite the ease of detection intentional cyanide poisonings still occur. This year the serial killer, Mohan Kumar – nicknamed “Cyanide Mohan” by the news media in India – was convicted of the murders of three young women and is suspected in another 17 deaths. Mohan, a 50-year-old former teacher, allegedly killed strictly for profit – he stripped the gold jewelry off the dead women and sold it. Let us not forget the Zimbabwe poachers who killed more than 300 elephants by poisoning their water hole with cyanide (not to mention the other animals that visited there) in order to sell their ivory tusks on the Asian market.

Makers of thriller movies and writers of murder mysteries tend to like cyanide for its dramatic tendencies – the quick gasping finish, the shocking immediacy of the way it kills. I had thought that an old, easily identified, messily visible poison like cyanide would fade away into our homicidal history. I say thought because if 2017 is anything to go by, that’s not particularly apparent. As the continuation of cyanide murder reminds us, we don’t easily set aside our past and we obviously – if unfortunately – hate to give up on a weapon with a history of working so well.