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.

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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.

2014 Science Highlights: Part 1


Another year passes, so it’s time for another round up of the most interesting scientific events that have happened in the last 12 months. 2014 has been a year full of fascinating discoveries, both in this planet and outside of it, but with some disappointing realisations too.

 1. The Ebola Crisis Continues

ebola

The Ebola virus keeps taking lives and will continue to do so until we find a treatment

The Ebola virus gained a lot of attention this autumn when it grew to an unprecedented size: it became the larges Ebola outbreak in history. In fact, the WHO declared it a global public health emergency and many countries and organisations rushed to contribute some help. At first contained in West Africa, there were a couple of isolated cases in Europe and the USA which caused even more panic, but it has died down. As with many catastrophes, after the initial spotlight, the Ebola pandemic has lost a lot of attention from the public, even though it has not stopped growing. However, it is slightly more controlled, and due to all the press it received, plenty of research is going into treating it, which should hopefully yield some treatments or a vaccine.

2. Stem Cells Stump

Mouse embryo with beating heart

The original STAP cells, which held so much potential, but turned out to be too good to be true

There was a great flurry of excitement at the beginning of this year when researchers in Japan claimed to have created stem cells by simply dipping blood cells into acid. The STAP (Stimulus-Triggered Acquisition of Pluripotency) cells were great for medical research since they got rid of the ethical issues of using embryonic stem cells. The potential of this easy and cheap method were immense, so as soon as the results were published, many scientists from around the world tried to carry out the experiment themselves. But they couldn’t. The results couldn’t be replicated. A more in depth investigation showed that the results of the original experiment were not accurate, and now the theory has, unfortunately, been disproved.

3. Rosetta and Philae

rosetta philae

A representation showing Rosetta (left) and Philae (right) on the surface of 67P

You can’t summarise 2014 without mentioning either the Rosetta spacecraft or the Philae lander. They have both accomplished feats in science which could have only been dreamed of. Rosetta has been in space for 10 years in pursuit of the 67PN comet which is travelling through our Solar System. This year it finally reached it and is now moving relative to it, becoming the first object to rendezvous with a comet. But Rosetta is not the only one who’s kept busy. After rendezvousing with the comet, Rosetta released Philae, a small robot whose objective was to land on 67P. And so it did, although it was a bumpy ride. Unfortunately, it ran out of battery soon after the landing, making it impossible for it to analyse the comet and take samples; its original purpose. But 67P is supposed to pass close to the Sun at some point, which might reactivate Philae and help it complete its mission

4. Dusty Waves

primordial waves

The graph showing what scientists thought were primordial waves, the proof of inflation theory, but is actualy dust

There was another fascinating discovery this year, in which a special type of wave was detected coming from space, with massive implications. Called primordial waves, they are theorised to have been produced during the Big Bang, and if their existence was confirmed, the theory of inflation, which states that the universes started expanding just after it was created would be proved. What were supposed to be these waves were then detected, and scientists were ecstatic. The Big Bang is one of the most confusing aspects of science, and this discovery could help clarify it greatly. But again, after further investigation, the results did not look too good. The alleged ‘primordial waves’ were most likely just dust in the Universe, interfering with the results and creating false hopes.

5. Young Calls Young

blood

Blood could hold secrets for eternal youth

In a truly zombie-like procedure, scientists sewed young and old rats together so they created blood vessels between each other and shared blood. After some time, they investigated how tissues had grown and developed in the two rats and the results were utterly fascinating. The old rats had created more neural connections in their brains, their muscles had healed faster, and their heart muscles had been rejuvenated. However, the young mice suffered the opposite effects.

But scientists concentrated on the positive side, on what chemicals in the young rats caused these changes in the old ones and detected a specific protein, GDF11, which seemed to activate stem cells and cause all these beneficial effects. They also discovered chemicals in older mice which did the opposite: they made stem cells react slower, which in turn deteriorated the health of the younger rats. The next step is finding the equivalent proteins in humans, so that older people can be healed from diseases such as Alzheimer’s or arthritis.

 

Stay tuned for the more of the most interesting scientific events of 2014 in the epic conclusion: 2014 Science Highlights: Part 2.

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.

On Z(4430) the Tetraquark


Scientists are always finding new particles or new phenomena that enlarge our existing pool of knowledge. And said pool has just become larger thanks, once again, to the LHC, which now says they have found a new type of matter.

Matter can be found in many forms, from solids in a macroscopic level, to protons, and even further down, to quarks. These last ones are the most primary building blocks in our universe. They make up protons and neutrons, which then form atoms, which then form elements and then everything we see nowadays.
But quarks don’t exist just by themselves. The come together in groups of two, called mesons, or in groups of three, which form protons and neutrons. But now, the LHC has supposedly found a new particle that consists of 4 quarks, forming a tetraquark. This mythical particle is being called Z(4430), due to the current naming system which says all ‘tetraquarks’ need to have names starting with a Z, for organisational purposes.

Z(4430)

Graph of results proving the existence of Z(4430)

Up until now, they had only been theorised, never actually proved, since the necessary calculations were far too complicated for even our most modern computers to attempt. But even then, this is not the first time a tetraquark has been presumably found. It has happened only once before, in the Belle Detector in Japan, where they also thought they had detected a tetraquark. In that case, other labs tried to find the particle, but since they were unable to do so, the particle’s existence was severely questioned.
The difference this time is that the LHC has detected Z(4430) for over 4000 times, in over 10 times the amount of data the Belle Detector had, undoubtedly proving this particle something worth studying.

There is, however, a slight problem with this particle. The basic theoretical models, (those that can be carried out without the use of complex computers), predict that tetraquarks should have a decay time of 10 times the decay time of Z(4430). This nagging little obstacle will have to be passed with more research into this particle, to finally unravel the mystery of whether this particle is just another mistake in the history of science, or if it is in fact one of the basic fragments of nature.

Detecting Baby Waves


In Einstein’s theory of general relativity, he said that massive objects moving at incredible speeds, or giant objects’ gravity interacting could cause ripples in the space-time fabric, known as gravitational waves. They had been searched by scientists for years, and they had successfully hidden, but not anymore.

A series of experiments taking place in the South Pole have finally provided the scientific community with a solid detection of these elusive waves. The project, called BICEP2, has released its findings today, and are awaiting further revision for official publication.

gravitational echo

The graph showing the primoridal gravitational waves when first detected.

There has been a lot of excitement over these waves, because they are able to prove one of the most popular theories regarding the birth of our universe: inflation. The theory, suggested by physicist Alan Guth, says that a few moments after the universe was created, it suffered a dramatic increase in size (by a factor of 1078). After this, its expansion rate slowed down considerably.

What’s important is that if this theory was correct, the sudden growth would have caused ripples in the space-time, hopefully strong enough for us to detect.

And this is what this amazing team has done. They have detected the gravitational waves that were given off during the expansion, given the fancy name of primordial gravitational waves.

The results are impressive just by themselves. The fact they have caught these waves is already world-changing, but there are even more interesting details that deserve our attention.

The waves they found were stronger than they thought they could be, which leads to a rethinking of the current inflation theory. There are some ‘sub-theories’ that can explain this fact, so many eyes are turning towards these and reconsidering them for answers.

But if there’s something we’ve learnt after all these years is to remain cautious after big discoveries (incredible stem cell method not that incredible after all?). The findings have yet to be backed up by other experiments from other teams, but overall there is a positive feeling towards this data.

If they were to be true, they would prove inflation to be true once and for all, but they could also prove useful in completing quantum mechanics. This field is very effective when working with subatomic particles, but when you add gravity, it all goes to rubbish. An understanding of gravitational waves could be useful and could help scientists find that key they need to wrap it all up.

 

Check out BICEP2’s official website:

http://www.cfa.harvard.edu/CMB/bicep2/science.html

Quantum Droplet


Quasichemistry is a branch of chemistry that studies a special type of particles called quasiparticles.

These are different from normal particles because they cannot exist individually, but only inside of solids. They act as if they were floating freely in space, with weak interactions with other particles.

For example, it is believed an electron, although a fundamental particle (the simplest substance which doesn’t have any substructure), is made of 3 quasiparticles, a holon, a spinon and an orbiton. Each of these quasiparticles has a different characteristic that codes for the electron. The holon carries the electron’s charge, the spinon its spin and the orbiton its location in the orbit.

dropleton

Named dropleton because it’s like a liquid drop

However, they are not real particles, just a mathematical tool used to simplify the way electrons and nuclei move in a specific way.

There have been many quasiparticles discovered, and they are used to explore the quantum world in more depth. So every time a new quasiparticle is discovered it’s a celebration that we are closer to understanding physics at it’s smallest level.

Recently, a new quasiparticle was created, the “dropleton” (named because it’s a quantum droplet).

The way it is created is when a short laser pulse was directed at a semiconductor made of gallium arsenide. The energy given to the material causes electrons to move, creating excitons (pairs of holes in a material because of the absence of an electron). Once there are many excitons, they start joining to electrons, and moving around the solid.

But what’s interesting is the way they travel. Normal quasiparticles move like normal particles, but the dropletons flowed, rather than moved. In fact, they behaved like a group of particles in a liquid. It’s the first quasiparticles to act in a liquid fashion.

They are also special because of their longevity. They last for 25 picoseconds, which although is extremely short period of time for us humans it is quite a long time in the quantum world. This and their size (200 nanometres) allows scientists to test them and discover more about them. Not only that, but they also form stable structures. The smallest dropleton is 4 electron-hole pairs; the biggest is 14.

Higgs’ Roar


Celebrating the Big Bang Theory’s 50th birthday, scientists in Finland have run the first 3-dimensional simulation of the first seconds of the famous explosion, to investigate the effect the newly born Higgs field would have had, and have discovered it has loud repercussions.

The Higgs field is what gives most particles their mass, and is generated by the Higgs Boson, the last particle to be discovered in our current physics model which we use to explain the universe.

However, when the universe had just appeared, and new particles were being created with it, they didn’t have mass at first. It was only 100 picoseconds later that the Higgs field was turned on and mass appeared.

Of course, this sudden change in the composition of the universe (from having no mass at all to being filled with it), would have had a noticeable effect. It could be thought that the field started acting evenly around the universe, but a theory suggests that Higgs fields were generated in bubbles that started spreading in random areas (like bubbles in boiling water), growing and giving mass to any particles they happened to engulf.

But what happened when two bubbles collided? This is question (and the consequent answer) that has real implications.

When interacting with each other, the bubbles would have caused a disturbance in the space-time

bubbles

Higgs Fields could’ve spread around the space time tissue like bubbles

fabric, causing a series of ripples of gravitational waves, which are unfortunately too weak for us to detect. But they would’ve also released large amounts of energy to the particles, therefore creating shock waves or sonic booms. These would then be translated into low rumbles that would have subsequentially caused more gravitational waves. These two sets of waves, when joined together, could gain enough force for us to eventually detect them, although not with our current technology. We will have to wait until we develop more sensitive detectors that are capable of detecting these waves until we can finally approve this theory.