Author Archives: Gilead

About Gilead

A servant of two Masters (in Theoretical Physics and Science Communication), Gilead's a former organiser of TEDxImperialCollege and TEDxAlbertopolis who hawks his wares over at gileadamit.wordpress.com and walks his hares through Regent's Park.

chicago green

There’s something in the water

Tomorrow is March 17th, and as they have done every St Patrick’s Day weekend for 52 years, members of Chicago’s Journeymen Plumbers Union have already set about the herculean task of dying their city’s eponymous river a brilliant shade of emerald.

The transformation pays tribute to all that Irish immigration has done for the city, an act of recognition unique to Chicago, and one that is sure to make expat Paddies the world over turn green with envy.

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But the extraordinary effect is surprisingly easy to achieve. All it takes, say the journeyman plumbers, is 18 kg of vegetable dye to give nearly 3 million cubic metres of water the hue of a leaky fluorescent marker.

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Wellcome Library, London

Modern plagues & ancient diseases

In his 1821 play Almansor, Heinrich Heine wrote that wherever books are burned, eventually they will also burn people. This eerily prophetic quotation is now emblazoned on the site of the infamous Nazi book-burnings at the Bebelplatz in Berlin.

If we have come to accept that those with no respect for human accomplishments will in the end become equally disdainful of human life, it should come as no surprise that the reverse also holds true. Cue this week’s unhinged destruction of a museum at the historic Iraqi site of Nineveh by the ongoing jihadist frat party that calls itself Islamic State.

Among the priceless artefacts that were put to the sledgehammer and electric drill were two statues of human-headed bulls dedicated to the Mesopotamian God Nergal, built around 700 BC.

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Among many other things, Nergal is known today as the Sumerian God of Sickness and Death, and the study of his worship therefore offers fascinating insights into the spread of infectious diseases across the ancient Near East.

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man's foot about to slip on banana peel

Pulp Friction

Tripping on a banana skin can have an audience rolling in the aisles. Assuming, of course, you’re careless enough to leave one lying around.

The now ubiquitous slipping-on-a-banana-peel gag is thought to date at least as far back as 1879, when Harper’s Weekly magazine warned its readers against following in the literal footsteps of inconsiderate fructivores. The great novelist Umberto Eco, for his part, believed that the iconic banana skin evolved as a visual euphemism for far deadlier heaps of dog detritus.

Never having slipped on a banana skin, I’ve often wondered just how dangerous they can be. And for that matter, whether it’s the inside or the outside of the fruit that poses the greater health hazard. Fortunately, these are exactly the sort of slippery questions that scientists have been falling over themselves for decades to peel back and really sink their teeth into.

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In 2012, Kiyoshi Mabuchi and colleagues at Japan’s Kitasato University in Japan decided to formally investigate this phenomenon, by studying the coefficient of friction of banana skins. Their results appeared in the journal of the Japanese Society of Tribologists, a term for scientists who study the way moving surfaces interact.

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Konigsberg3

A bridged history of Königsberg

To mathematicians, they are the most famous bridges in the world. Spanning the river Pregel as it flows into the Baltic Sea, the Seven Bridges of Königsberg are today virtually synonymous with the field of topology, the mathematical study of shapes.

Their immortality was assured in 1735 when Leonhard Euler, the great Swiss mathematician, became intrigued by the city’s unique geometrical configuration. In addition to settlements on the north and south banks of the river Pregel, 18th Century Königsberg also included two large islands known as Kneiphof and Lomse. These islands were connected to the mainland as well as each other by seven bridges that were central to the city’s life.

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Euler wanted to know the answer to a comparatively simple question: would it be possible for a visitor to cross each and every one of Königsberg’s seven bridges once and only once? Being a mathematician and not a tourist, it didn’t matter to him whether the visitor started in the same place as she finished.

Such a path, Euler eventually concluded, would not be possible. The visitor (let’s call her Doris) would either find herself stranded on Kneiphof or else forced to angrily patrol the riverbank waiting for the authorities to build her another bridge. Needless to say, Euler refused to consider either jumping or swimming as valid options.

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Hefele

Duet Yourself – the science of polyphonic overtone singing

When most people praise the quality of a duet, they expect to be congratulating two people. But, as a video that’s gone viral this week has proved, that assumption need not always hold true. In just over eight days German singer Anna-Maria Hefele has racked up 4 million views on YouTube by demonstrating her phenomenal ability to sing two separate melodies at the same time.

Hefele’s performance is an example of polyphonic overtone singing, a technique which allows her to produce two distinct notes in perfect harmony.The lower of the two is generated by the vibrations of vocal folds in the larynx: the same process as occurs in everyday speech. This sound wave is said to have a fundamental frequency, as it has the longest wavelength that will fit inside the resonant cavity formed by the speaker’s mouth and throat.

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The Kilogram turns 125

We all know what a kilogram is, right? It’s the mass of a bag of sugar. Thank goodness for the bag of sugar. Without it we’d be forced to imagine 1/7000th of an African bull elephant or 1/14560th of a double decker bus or God only knows what fraction of the weight of Wales.

Having a clear visualisation of the kilogram is important for all sorts of reasons, not least because it’s one of the seven SI units, the fundamental alphabet of symbols which can be combined in a variety of ways to express any physical quantity. Speed, for instance, is measured in metres per second, whereas force can be expressed in terms of kilogram metres per second squared.

The kilogram was accepted into this metrological pantheon alongside the metre 125 years ago today, when the value of both units was defined at the first General Conference on Weights and Measures organised by the BIPM. As a consequence of that meeting, three identical kilograms were cast by the firm Johnson Matthey out of a mass of platinum-iridium alloy. This alloy was chosen because of its density and chemical stability, meaning that the kilograms would be both small and resistant to rust. One of the kilograms was kept at the BIPM offices in Sevres, and two were sent for safekeeping in America. Rumours that a further three were subsequently distributed to the elven-kings under the sky have no foundation in truth.

One kilo to rule them all

One kilo to rule them all

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NYTblue

Nobody ever said dyeing was easy

As anyone who has ever attempted to buy wallpaper with a loved one will know, colours are notoriously difficult to define. One man’s Burgundy is close enough to another woman’s Maroon for Red to be a dangerously ambiguous catch-all term.

But what if more were at stake when choosing colours than marital happiness. What if the choice of one particular shade of blue over another constituted a religious sin. And – as if that weren’t bad enough – what if nobody had actually set eyes on the colour in question since the days of Ancient Rome.

This chromatic grey area is not a hypothetical situation. The disappearance of the colour t’khelet (pronounced with a properly phlegm-filled ‘kh’, if you please) was a pressing question in Jewish theology for well over a millennium. It took generations of rabbis, dye-makers and chemists to bring the dye back from the dead, and in the process explain just how it was that the Jews first got the blues.

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In the Old Testament’s Book of Numbers (chapter 15, verse 38), the Lord tells Moses to instruct the Children of Israel to “make for themselves fringes on the corners of their garments, throughout their generations, and affix a thread of t’khelet on the fringe of each corner.”

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Edward Drinker Cope

The largest dinosaur ever found – and subsequently lost again

What’s the largest animal ever to live on planet Earth? Whether you’re measuring in double decker buses, swimming pools or African elephants, any budding naturalist will be able to tell you that the answer is the blue whale. At 31 metres long and weighing 146 tonnes, this enormous cetacean easily exceeds the paltry dimensions of such pretenders as diplodocus and Tyrannosaurus rex. In London’s Natural History Museum, one of the rare institutions where life-sized models of both animals exist side-by-side, the blue whale has a good three metres on Dippy the beloved Diplodocus.

The blue whale has had to fend off another challenger this week, in the form of Dreadnaughtus schrani, a behemoth from 77 million years ago thought to measure 26m from tip to tip. Dreadnaughtus has made headlines as the most complete sauropod skeleton ever discovered, a body of evidence which provides ample confirmation of its titanic size.

But the absence of such complete remains has never stood in the way of scientists looking to predict an animal’s length and height. The dimensions of the largest dinosaurs have often been extrapolated from just a few fragments of their enormous skeletons. In one notable case, the discovery of a single vertebra led to the prediction of an entirely new species of dinosaur, larger than any that had come before or since. A dinosaur that would make the blue whale look like small fry: Amphicoelias fragillimus.

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Hex Codes featured image

What the hex?

Chances are, the screen you’re currently looking at is capable of displaying over 16 million different and uniquely identifiable colours. As those of you who’ve done digital design work will probably know, each of these colours can be represented by a Hex code – a six-character string of letters and numbers.

But where do these odd symbols come from? And what do they mean? And – most interestingly of all – is it possible to work backwards from the Hex code to correctly identify the colour?

Following on from Matt’s phenomenally successful liquid nitrogen bucket challenge, I’ve decided to undertake a challenge of my own – the paint bucket challenge. Don’t worry though – none of you has been nominated!

Gilead Amit is a big consumer of colour, and particularly enjoys a nice glass of red. He tweets at @gileadamit

DocWho

The science at the end of the Whoniverse

Yes that’s right, Doctor Who is back on our screens, spitting himself out of dinosaurs’ mouths and into our hearts where he belongs. On this week’s episode, the first of Series 8, a homicidal android is stalking the streets of Victorian London, mutilating golden-hearted cockneys for their fleshier organs and turning the remains into donor kebabs in order to conceal the evidence of his crimes.

Slap bang into the middle of this mess lands the Tardis, lodged inside the throat of an exceptionally irritable tyrannosaur. Trapped on board are the wide-eyed Clara Oswald and the new and improved Time Lord Peter Capaldi – whose saurian features make the aforementioned reptile look positively cuddly.

The Doctor’s arrival is greeted with a clash of symbols.

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