Boosting Spiders


Arachnophobia, the fear of spiders, is one of the most common fears, affecting slightly less than 50% of women and 15% men. But regardless of how scary they can be, spiders are fascinating creatures, and you can’t deny their skill. They can spin the second toughest natural material in this planet: spider silk.

Spider silk can be found in spider webs, which are made by quite the process. It is called ballooning, a hilariously weird name that describes the method by which spiders release silk strings into the air so the wind carries them away, until they attach to a surface. Step by step, fibres criss-cross until a web is formed.

You may have already met this creation when cleaning your old, dusty attic or from running face first into them in the woods, but what many people don’t know is that its strength is, in proportion, comparable to that of steel. However, it may not seem as strong because it is much thinner and less dense.

But let’s not get too caught up in spiders and their ways of life. Although their silk can boast of incredible characteristics, we as humans always insist on pushing harder and trying to improve what we see. In this case, this lead to scientists to add a man-made touch into the mix to toughen up silk.

Two groups of spiders, both from the species Pholcidae, were kept in different environments. One group was sprayed with water and graphene molecules dissolved in it whereas the others got water with carbon nanotubes. Then, in a mechanism still unknown to the researchers, the spiders were able to use the carbon compounds in the solutions to make stronger silk. This could’ve happened because they drank the water and the graphene and carbon nanotubes ended up in the silk-producing areas of their bodies or more simply, because the silk ended up covered in the solution and the compounds coated it.

spider web

Let’s hope the toughened up spiders don’t rebel against us

That is what the team of researchers will be investigating further, but for now, they are basking in the glory of being able to produce the strongest fibre ever: an artificial silk between 3.5 and 6 times stronger than the natural version. In perspective, this means the silk produced by these buffed up spiders is just as strong as Kevlar, the material used in bulletproof vests.

Who knows where this coalition between spiders and humans could go next. One idea is to repeat the process with other animals, like silkworms, which also produce their own type of silk. Before though, they need to know how we could actually use this type of silk, whether in sutures and clothes or in the craziest idea yet: creating huge silk nets strong enough to catch and hold falling airplanes.

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Precious Faeces


Treasure hunters spend their lives looking for valuable objects like gold coins and silver ornaments in shipwrecks or archaeological sites, often involving dangerous stunts. But tonnes of precious metals are actually hiding in plain site, right where you wouldn’t expect them: in your faeces.

gold stuff

Who knows where this gold actually came from…

Many products we use in our day-to-day life, like shampoos and detergents, contain precious metals, which gather up in urban pipes. Or they can be found in the food and drink we consume and that, after a while, accumulates in our body until is removed by excretion, which also ends up in the sewage drains. So imagine if this process was carried out by thousands of people, all living together in a city. The amount of valuable elements in the sewage would be outstanding! And so has been confirmed in a study by the US Geological Survey that found out that the concentration of precious metals in a city’s sewage system is comparable to that in an actual working mine.

For example, in a single kilogram of ‘sewage slime’, you can find 0.4mg of gold and 28mg of silver, metals used in jewellery; 638mg of copper, a metal used in electrical wiring and 49mg of vanadium, which has important industrial applications. But in the larger scale of a whole city, it has been calculated that by all these metals being thrown into the sewers, up to £510 million a year are being lost in the UK.

In an attempt to profit from this waste, companies are starting to consider human faeces as a viable source of precious metals. It’d be quite a profitable venture for them, and much greener than traditional mining since instead of using hazardous chemicals in lands where they can contaminate a habitat, they are used in an enclosed factory. And although working with faeces sounds like an outrageous idea and a bad time, it has been done for many years now, as it is used to make plant fertilizers.

As a fortunate side effect, we would actually be making our excrements cleaner and therefore protecting the environment. Faeces not only contain gold and silver, but heavier metals like lead which can be toxic to an ecosystem. By processing our waste, we’d make sure that not only the valuable metals are removed, but the harmful ones too. This idea just gets better and better!

So who knows, maybe someday in the near future you will wear gold bracelets that come from your faeces, or phones with microchips made of components of our waste.

A Chameleon’s Colourful Secret


Chameleons are definitely one of the most fascinating creatures on Earth, and their characteristic colour changes, to camouflage themselves or gain the attention of their mates, can impress both kids and adults alike. As if their ability to change their appearance into anything they’d like wasn’t enough, the mechanism by which they do so could also be unique and worth some credit.

In nature, colours are usually produced by pigments: substances that have a specific colour. For example, our skin gets tan because of a pigment called melanin which darkens it. In chameleons, it was originally thought that they showed one colour because a pigment of that same colour covered their skin, and when they wanted to change colour, a pigment of a new colour just substituted the original one. But it has now been discovered that their colour change, contrary to popular belief, had nothing to do with pigments. It’s actually all because of crystals.

A chameleon’s skin has an outer layer full of specialised cells called superficial iridophores, which have tiny guanine crystals embedded that can reflect light at different wavelengths and so produce different colours. Guanine not only plays an important role for this process, but is also one of the four bases in our DNA, which code for all the substances in our body. When the chameleon wants to change colour, it simply twist these cells around so the distance between crystals changes, which causes the reflection pattern, and subsequently the colour it produces, to change.

chameleon coloured

Chameleon’s can express a wide variety of colours thanks to guanine crystals

This is a very smart design which saves the chameleons a lot of energy and resources on producing and transporting the pigments around. If the animal wants a bluish colour, it just needs to push all these crystals together. For a reddish/yellow colour, just spread them out.

The only thing yet to be discovered is how the chameleons actually modify the superficial iridophores’ shape. In the experiment they carried out to test this new theory, they used salt water to expand and contract the cells and see what effect this had on the colour. But the natural process in chameleons is not necessarily chemical, it could be mechanical. Finding out which one it is is the team from the University of Geneva’s new objective.

Either way, discovering the truth behind this ingenious technique is not only an interesting fact to know about, but could also have real-life applications, for example, in developing computer screens.

FrankenBattery


We live in a world where energy is currency. Wars are fought over petrol and other fossil fuels, whilst millions of people work tirelessly to provide alternatives like solar energy to prevent global warming and provide a greener and safer future for our planet.

Since energy is so important, a lot of research is put into it, yielding fascinating results. The most recent one has to do with lithium-sulfur batteries. Their mechanism is not new; in fact, it has been known for decades. But there have always been practical imperfections with their functioning. Scientists seem to have discovered a way to solve them and create one of the most useful batteries to date.

lithium sulfur battery

Lithium-sulfur cells coould soon power your phone, your computer, your car, etc…

Normally, this battery consists of two electrodes, one made of lithium and the other of a carbon-sulfur compound. When the battery works, ions from one electrode move to the other through the electrolyte, creating a current. Unfortunately, lithium can react with the sulfur and form lithium sulphides, which dissolve into the electrolyte and slowly use up the sulfur electrode. Up until now, the solution had been to add some other chemicals, like titanium oxide or manganese dioxide, which would stabilise the sulfur and prevent it from dissolving so easily in the electrolyte. But the method which seems the most promising is actually the most unexpected: adding DNA.

Yes, you read that right. DNA, deoxyribonucleic acid, the organic molecule that codes for all of our characteristics actually improves lithium-sulfur batteries. DNA is made of oxygen, nitrogen and phosphorus, and luckily for material scientists, all these elements easily bond with sulfur. This makes DNA ideal for trapping sulfides, preventing them from dissolving in the electrolyte. In turn, it improves the efficiency of these batteries by almost 3 times. Even better: DNA is cheap and biodegradable, and a very small amount is needed for it to improve the battery’s performance.

The interest in this specific type of batteries is not unjustified. They have a high energy density (can deliver up to 3 times as much energy as lithium ion cells), are cheaper to produce and greener for the environment. It is therefore not strange that scientists are trying to do as much work as possible to help improve this technology. However, the battery world is a slow one, and although an idea may look good in the lab, it is harder to extrapolate that into the industry. But keep your hopes up! Lithium-sulfur batteries could very well substitute the widely used lithium ion cells in only 15 years, with original ideas like the one exposed on this article to push it through.

Light Sprints


light pulse

Small light pulses can now be modified so they slow down

Remember any physics lessons during your high school years? How it was always said the speed of a light was the most unchangeable constant of all? Well… keep reading. In a perfect example of how science changes to perfect itself, scientists at the University of Glasgow have carried out a very interesting set of experiments which ultimately showed that the speed of light can in fact change.

Now, we all know that when light enters a medium, such as water or glass, it slows down. Whereas the speed in a vacuum is said to be 299 792 458 m/s, it can go down to 225 056 264 m/s in water and even 124 018 189 m/s in diamond. This is due to the increased density through which the light has to pass through, so the light particles suffer more collisions which slow it down. But the news come from the idea that speed can also change in a vacuum, even if there is no change in medium and therefore in density.

However, there is a trick. This change in speed won’t happen spontaneously, it has to be slightly triggered. Although it is usually simplified as ‘straight’ or plane waves, where every point travels parallel to each other, light is a bit more complex than that. Two points in a ray of light can actually converge and join, bending their shape. When this effect happens, light speed is affected.

The experiment consisted of a source emitting only two photons. One of them was directed to flow through an optical fibre, so its journey was not interrupted and was as smooth as possible. The other one was passed through a series of apparatus which changed its structure for a short period of time and then restored it back to normal. The time it took each of the photons to arrive to the finish line was measured very precisely. No matter how many repeats the team conducted, the modified photons were always slightly slower and arrived after the untouched one.

The change is speed is not immense, and will have no effect on day-to-day calculations, but it could be have some importance on experiments which use short pulses of light. The fact this effect exists is already worth noting, as it is theoretically obvious but no one had proved it before.

Nobel Prizes 2014: Part 1


Probably the most prestigious scientific award, the Nobel Prize is, for many, the intellectual event of the year, where the world’s greatest scientists are rewarded for their hard work and brilliance. As of yet, only two results have been announced, those for physics and physiology, and the rest will be unveiled as the week progresses.

The 2014 Nobel Prize for Physiology or Medicine went to… John O’Keefe, May-Britt Moser and Edvard Moser for discovering the ‘GPS’ system in brains.  

human gps

Not a literal GPS in our head, but a group of cells that enable us to travel

It all started 40 years ago, when O’Keefe was investigating rats’ brains and their response to certain stimuli to understand their behaviour. In one experiment, he found that in a group of nerve cells in the brain, some became active when the rat physically moved to one area of the room, whilst other cells became active in other areas of the room. The conclusion he reached was that this group of cells was making a mental map of the rat’s environment to help it locate itself and move around. The ‘place cells’, as he called them, were a revolution in the field, but it took O’Keene 40 years and two collaborators to win the famous Prize.

The other recipients of the award are the Mosers, a married couple who, working in O’Keene’s lab, examined in more depth the mechanism and using modern technology, discovered that a close group of cells in the entorhinal cortex also helped in movement. What they found was that these new cells could be active in many positions of the room, not just one specific location. ‘Grid cells’ is their name and they do exactly what their name would suggest: they create a grid of their surroundings.

Both the place cells and the grid cells are used in human brains too, and their work is essential for us to be able to travel, even from one room to another, without getting lost.

The Nobel Prize for Physics went to… Shuji Nakamura, Isamu Akasaki and Hiroshi Amano for the invention of blue LEDs.

At first sight, it looks like they gave these men a Nobel Prize for inventing a bulb, but it is much more complex than that. First of all, let’s explain what an LED is and how it works. An LED stands for Light-Emitting Diode and it is used to produce light. It works by having thin sheets of material over each other, some of which contain a lot of electrons whereas other don’t and so have positive ‘holes’. When an electron collides with this hole, it emits a photon; a particle of light.

blue led

Making blue light is much harder than it may seem!

Red and green LEDs have been around for a long time, but only blue light could be transform into white light. The problem is that blue light has a higher energy and therefore very few materials can emit this wavelength. So when Akasaki, Amano and Nakamura discovered gallium nitride, it was a real miracle. This material is special because apart from having electron-rich areas, it can also produce a layer of itself which lacks electrons, so that together, they can react and produce blue light.

This apparently simple mechanism has had unimaginable consequences, which is the main reason why the Royal Swedish Academy of Sciences has decided to award them the prize. Blue LEDs gave us the opportunity to make white light by coating the bulb with a substance called phosphor. Thanks to this combination, we now use blue LEDs everywhere, from our TV screens to the lightning in the streets. The advantage it has over the normal, incandescent bulbs is that it can last 100 times longer, and is extremely more efficient. In fact, it is said that if all light bulbs were switched to these energy saving ones we could half the electricity usage by lightning in the whole world.

Shedding Light on Light


Messing around with the very essence of matter, scientists at Princeton University in New Jersey have managed to change the nature of light into unprecedented characteristics.

To do so, all you need is a superconducting wire with photons flowing through it and a machine containing 100 billion atoms made of superconducting material. Easy, right?

These atoms can then be modified to act as one single atom, thanks to the unusual properties of superconduction and so once this is done, you just need to push these two objects closer to end up with a group of photons acting like crystals.

light

Light as we know it has drastically changed

This is so bizarre because usually, photons of light are free from interacting with each other. But in this experiment, they were able to ‘bond’ together to form a crystal structure. This happens because of a quantum process called entanglement, where two photons can become connected over large distances. When the giant atom was brought closer to the photons, these linked to it and exhibited similar properties to it, effectively making light solid. The mechanism could be varied so that light behaved like a liquid or a gas, and with further refinements, like even more exotic materials such as superfluids; fluids with zero viscosity which flow defying gravity.

Although this discovery sounds like just interesting information, it actually has applications. Obviously, it is important to understand matter and how it works (a science named condensed matter physics), since it brings us closer to discovering new materials or characteristics of objects which we can use in our favour. For example, it could help devise the very sought-after room-temperature superconductor, with which electricity could be transmitted in our day-to-day lives with an incredible efficiency, since it offers no resistance.

As if the nature of light wasn’t hard enough to comprehend already, with wave-particle duality, here’s a new behaviour to complicate things even more. Sorry, students, sounds like you’ve got something else to make sense of.

Welcome Ununseptium


The periodic table is like a big family, where every now and then a new member appears and joins the fun. Well it looks like we may have found this new character which could possibly become the largest element ever created.

ununseptium

Ununseptium has 7 shells, and belongs to the halogen group

This is Element 117, which was confirmed in an experiment who wasn’t even searching for it. It happened in Germany, where a group of scientists lead by Mr. Düllmann were actually looking to create element 119, an even heavier element. But it takes time to analyse the data produced by that experiment, so meanwhile they decided to try and make some Element 117, as a check to see if their detectors were working correctly. They certainly were, and in the process they created this interesting element for about a tenth of a second, until it decayed. It was made by bombarding atoms of calcium (atomic number 20) with atoms of berkelium (atomic number 97), which would then fuse together to form a heavy 117 atom.
However, this is not the first time this element has been synthesised. It has occurred twice before, in Russia, where scientists made the element in 2010 and once again in 2012.

The confirmation of this element’s creation means the organisations responsible for new elements (both The International Union of Pure and Applied Chemistry and that of Physics) will have to revise the data collected, to ultimately add this element to the Periodic Table. But don’t get too excited about this; it took 3 years of revision for them to accept elements 114 and 116. So we still have time to carry out new experiments and find out more about it.

Unfortunately, research in this element can be quite slow. As I said before, you need berkelium, an extremely rare element which only occurs in nuclear reactions, but has a short half life so it can take a lot of time to gather the necessary amounts.

A major surprise of this experiment is the discovery of a new Lawrencium isotope. Symbol Lr, Lawrencium has an atomic number of 103, and while element 117 was decaying, they discovered a new form of this element, which although doesn’t have many applications, can be used to expand our knowledge on the magnificent elements of the Periodic Table.

Blender Potion for Graphene


Graphene is quickly rising to become one of the most useful substances on Earth. It is an extremely hard substance, an excellent conductor of heat and electricity, and only 1 atom layer thick. Even better, it is as abundant as graphite, the black substance found in pencil leads, as graphene stuck together in many layers is in fact graphite.

But up until now, there had been a problem with this amazing material: its production. Obtaining some graphene is relatively easy: you get a piece a graphite from any pencil, and using some tape, stick and unstick it to the surface of the graphite continuously. This way, you will end up with a very small of graphene. This surprising method was discovered by two students at the University of Manchester: Andre Geim and Konstantin Novoselov, who won the Nobel Prize for Chemistry precisely for this technique.

graphene

This is graphene, a layer of atoms made of hexagonal carbon rings

The problem is that although this tape method works perfectly fine to produce some graphene, it’s not an efficient way to manufacture amounts large enough to meet the demand for this product. So scientists have been working non-stop to find a solution to their problem, and indeed they have found a very curious one.

Just as the original technique, its fairly straightforward. You just need some graphite, some water, soap and a blender. Now just add it all into the blender and turn it on. After a few seconds of work, you have produced a decent amount of graphene. The blades manage to cut between the layers of graphene in graphite and produce individual graphene.
The bright side of this process is that it produces 5 grams of graphene an hour, whilst previous methods produced only half a gram an hour. On the downside, however, is the fact that its not really as easy as this, and to get the best results you need to use more sophisticated substances and to get a decent amount the experiment would have to be scaled up.

It is still an enormous improvement compared to the previous methods that will for sure make this outstanding material more approachable, and all the technological revolutions it will bring closer to our reach.