Science

Lab_mouse_mg_3263

Cleaning Out Old Cells Prevents Aging in Mice.

Aging, as a process, still remains a mystery to modern science. We know that it’s not just one thing that causes the symptoms of aging which is what makes it so hard to find a miracle compound that erases everything. Still we’ve made some pretty good progress in combating some parts of the aging process, many of which can be used to make our lives not only longer but also far more healthier throughout. The latest research from scientists at the Mayo clinic shows yet another potential pathway for delaying the onset of age related diseases and conditions, giving mice up to 35% longer lives.

Lab_mouse_mg_3263

The mechanism that the researchers focused on is called cellular senescence. Our cells constantly reproduce themselves through division, a process which repeats for each cell approximately 40 to 60 times before it enters a stage called cellular senescence. In this stage the cell’s telomeres, a kind of nucleotide that protects a cell’s DNA from damage, is shortened to the point where it can no longer provide the protection the cell needs. In this stage the cell will no longer divide but still remains active. Eventually these senescent cells are cleaned out by the body’s immune system but as we age this process starts to slow down and become less efficient.

The Mayo researchers used an existing transgene line, called INK-ATTAC, to induce cell death in these senescent cells. This was triggered by twice weekly injections into two different lines of lab mice who were then compared to a control. The results were incredibly impressive, showing an improvement in overall lifespan of the mice from 17% to 35%. The mice also showed no side effects from the treatment with healthy major organ function retained throughout their extended life. Suffice to say a treatment of this nature would appear to be of incredible benefit to many, especially those who are seeking more healthy years than just an extended lifespan.

Such a treatment is probably many years away from reaching humans however, mostly due to the fact that the use of transgenes in humans is still an open area of bioethical debate. Indeed whilst the consensus for using such treatments for curative purposes appears to be largely agreed upon therapeutic uses such as these are still something of a grey area. Transgenes like this one are still very much an area of active research however and there are likely to be many more such treatments like these developed in the coming years. Hopefully the regulatory and ethical frameworks will be able to keep up with the rapid pace of innovation as treatments like these are invaluable in treating the one condition that affects all humans universally.

Bouncing Ball Bearings Beautifully.

Some of my favourite demonstrations of scientific principles are ones that you expect to behave one way but, in reality, act completely different. To me this demonstrates the value of experimentation and observation as you can never be sure until you do something for yourself. It also usually means that there’s some kind of interesting physical phenomena at play that I’m not yet familiar with, something which usually means an enjoyable trip down a Wikipedia hole. The following video is one such demonstration, showcasing an interesting property of amorphous metals.

In this demonstration (the whole channel is worth watching by the way) we can see the difference between an amorphous metal surface and a traditional one when a ball bearing is dropped on it. The difference in bounce height is quite staggering, enough to make you think initially that there’s some form of spring hidden in the cylinder. The actual reason for the difference, which is briefly touched on in the video, is far more interesting than it being a simple trick.

The material that the atomic trampoline is made of has some rather unique properties. Regular metals are usually of a crystalline structure meaning that their component atoms are highly ordered. Amorphous metals on the other hand (sometimes referred to as metallic glass) have a highly disorganised structure, owing to the fact that they’re usually alloys (made up of several different metals) and their creation process stops the formation of a crystalline structure.

This disorganisation prevents the formation of defects called dislocations which appear in crystalline metals. When a ball bearing strikes the regular metal surface these dislocations glide through the other parts of the metal’s structure, dissipating a lot of the energy. In the amorphous metal however there are no such dislocations and so much less of the energy is lost with each bounce. Of course the lack of dislocations does not negate other losses due to sound and heat which is why the ball bearing doesn’t bounce infinitely.

What I’d love to see is the same experiment redone in a vacuum chamber with both the ball bearing and the surface made from amorphous metals. I’m sure we could get some really absurd bouncing times with that!

Dry Ice Screaming.

Dry ice is a very interesting substance, both from a scientific and “it’s just plain cool” point of view. Many are familiar with the billowing clouds of smoke it can produce when placed in water, seemingly a staple of anything that needs to be made to look spooky. Others will know it for its culinary applications, able to cool things down far more rapidly than any fridge or freezer. However whats less understood is the mechanisms of how dry ice actually works which is what can produce some rather interesting effects like those shown below.

Dry ice is the solid form of carbon dioxide which, thanks to its useful properties, has found many everyday applications. It’s also quite easy to manufacture as carbon dioxide is a byproduct of many other processes. This gas is then trapped and pressurized, changing it into a liquid form. Then the pressure is released, causing some of the liquid to boil off which rapidly cools down the remaining liquid. This then forms a kind of carbon dioxide snow which can then be compressed into blocks or small pellets. Industrial applications often use the large blocks whilst the pellets are used in more everyday applications.

The video above demonstrates a property of dry ice that’s not completely obvious if you don’t know what to look for. Carbon dioxide doesn’t have a liquid state at atmospheric pressures which means that it transitions directly from a solid to a gas, bypassing the liquid phase. This process is called sublimation and means that the entire surface of dry ice is constantly emitting carbon dioxide gas. When you put something on top of it, like a large metal part shown above, the gas has to squeeze past the surface in order to escape. This is akin to pulling the ends of a balloon apart to make that loud screeching noise which is why this part appears to “scream”.

There are many other videos of people producing similar effects with dry ice and other metal objects like spoons and pennies. One interesting thing I noted from some of the other ones that the screaming effect would often stop after a short period of time. I believe this is due to the metal’s temperature approaching that of the dry ice which means that the dry ice no longer sublimates. The part in the video above is likely carrying quite a bit of heat which is why the screaming continues on for so long.

Quite fascinating, if I do say so myself.

Struggling Against Static Electricity.

Everyone knows the standard static electricity experiment. You grab yourself a perspex rod and a wool cloth and, after some vigorous rubbing (often with a few innuendos thrown in), suddenly your perspex has the ability to attract pieces of paper. Most people will also understand the mechanism of action, the transference of charge that leaves the rod negatively charged and the cloth positively charged. What most people won’t know however is that friction isn’t required to generate a static charge. This is what can lead to hilarious situations like the one in the video below:

So if friction isn’t a requirement for generating a static charge how do these address labels get it? The answer is actually pretty interesting and has to do with the way adhesives work. For these address labels the adhesion comes from a chemical reaction, meaning that the address labels had a form of bond with the backing before they were torn apart. When this bond is broken both materials will gain or lose electrons, depending on where the material sits on the triboelectric series. I’d hazard a guess that the material that the address labels is made up of tends more towards the negative end of the spectrum, meaning that bin holds a strong negative charge.

This is what is responsible for the labels floating around in a seemingly random fashion before ejecting themselves out onto the floor. The effect wouldn’t have been immediate, each label would only carry a small negative charge, however past a certain point the negative field would have become big enough to repulse the small weight of each of the labels. If they were so inclined they could throw a positively charged piece of plastic in there and they’d all be attracted which would also be pretty interesting.

Or, if you wanted some real fun, if they rubbed their head with a balloon and then dunked themselves in there all the labels would gleefully stick to them. Not that that proves much, just that it’d be hilarious to see someone with shipping label backing stuck to them.

Star Wars The Force Awakens

The Physics Faux Pas of The Force Awakens.

Before we get started let me just put this here:

LARGE PLOT SPOILERS BELOW FOR THE NEW STAR WARS MOVIE

There, now that’s out of the way let’s get onto the meat of this post.

Star Wars The Force Awakens

I, like all Star Wars fans, had been very much looking forward to the latest movie. Whilst I have my reservations about some aspects of it (which I’ll reserve for a conversation over a couple beers as to avoid a flamewar on here) I still thoroughly enjoyed it. However like most sci-fi movies The Force Awakens plays fast and loose with science. Following the rules of our universe when it suits the plot and sweeping them under the rug when it doesn’t. There are some grievances that I’m willing to let slide in this respect, this is fiction after all, however there’s at least one egregarious scene in which physics is completely thrown out the window when it really didn’t need to be.

My grievance lies with Starkiller base, the bigger and badder version of the Death Star which now encompasses an entire planet rather than just a small artificial moon. Whether such a device is something that could be built is something I’m willing to gloss over however the fact that it’s powered by drawing off mass from its neighbouring star brings with it a few niggling questions. It’s ultimate destruction, which then brings about the resurrection of its parent star, is also not something that would happen and not something I’d be willing to write off with space magic.

We get to see Starkiller base fire once and then begin preparations for firing again. Assuming that it didn’t travel to a new star in the interim (I don’t remember that being indicated as such) then it would’ve consumed half of its parent star’s mass to fire that single shot. That would’ve caused all sorts of grief for everything in orbit around it, not to mention the fact that that mass is now present on Starkiller base itself. Any asteroid or other debris near by should have rocketed down to the surface with incredible speed, laying waste to the surface. I’m willing to give a pass for a “gravity pump” or something else on the inside parts but being able to negate half the mass of a star over the entire planet is pure fantasy rather than a stretch of fiction.

However the final destruction of Starkiller base is the most egregious flaunt of the laws of physics. Putting aside all the mass contained within the star issue for a moment when it was all released the result would not be a new sun just like the old one. Whilst the mass was likely not compressed past its Schwarzschild radius (I’m assuming it’s a Sun like star) it would still be far too compressed to simply balloon back out. Instead it would likely become a white dwarf, that is if the explosion wasn’t violent enough to simply disperse the star’s material across its solar system. Since the system that Starkiller base resides in was never named I’m hazarding a guess it’s not relevant to the future plot so the returning sun just seems like a little bit of laziness more than anything else.

Of course I’m not advocating for 100% scientific accuracy in all films (indeed I don’t think there’s one good sci-fi epic that does) however a few nods here or there wouldn’t go astray. There are certain times where scientific accuracy would harm the plot and in that case I’m fine to relinquish it to induldge in the fantasy. Other times however it would do no harm and provide an interesting talking point as sometimes the physical reality can be far more interesting than the fantasy.

A River of Ice in the Desert.

Climate change is happening, there’s no doubt about that, and the main factor at play here is us. The last decade has seen an increase in the frequency and severity of weather events all of which can be traced to the amount of carbon we dump into the atmosphere. Thankfully the Paris climate deal is a good first step towards remediating the problem, even if the majority of the provisions in there aren’t legally enforceable. Until we start true action though extreme weather events will lead to things like below, where a river of ice flows through the middle of a desert:

The river, which on first glance appears to be a flow of sand, was caused by extreme weather in Iraq that saw the country blanketed in heavy rain and hail. The ice then overflowed rivers and ended up creating this incredible phenomenon. It’s also the second freak weather event to hit Iraq since its last summer, when the country experienced an extraordinary heat wave where temperatures hit 52°C in Baghdad. Whilst things like this are interesting they’re a symptom of a much larger issue, one that we all need to work together to solve.

D-Wave 2X

D-Wave 2X Finally Demonstrates Quantum Speedup.

The possibilities that emerge from a true quantum computer are to computing what fusion is to energy generation. It’s a field of active research, one in which many scientists have spent their lives, yet the promised land still seems to elude us. Just like fusion though quantum computing has seen several advancements in recent years, enough to show that it is achievable without giving us a concrete idea of when it will become commonplace. The current darling of the quantum computing world is D-Wave, the company that announced they had created functioning qubits many years ago and set about commercializing them. However they were unable to show substantial gains over simulations on classical computers for numerous problems, calling into question whether or not they’d actually created what they claimed to. Today however brings us results that demonstrate quantum speedup, on the order of 108 times faster than regular computers.

D-Wave 2X

For a bit of background the D-Wave 2X (the device pictures above and the one which showed quantum speedup) can’t really be called a quantum computer, even though D-Wave calls it that. Instead it’s what you’d call a quantum annealer, a specific kind of computing device that’s designed to solve very specific kinds of problems. This means that it’s not a Turing complete device, unable to tackle the wide range of computing tasks which we’d typically expect a computer to be capable of. The kinds of problems it can solve however are optimizations, like finding local maximums/minimums for a given equation with lots of variables. This is still quite useful however which is why many large companies, including Google, have purchased one of these devices.

In order to judge whether or not the D-Wave 2X was actually doing computations using qubits (and not just some fancy tricks with regular processors) it was pitted against a classical computer doing the same function, called simulated annealing. Essentially this means that the D-Wave was running against a simulated version of itself, a relatively easy challenge for a quantum annealer to beat. However identifying the problem space in which the D-Wave 2X showed quantum speedup proved tricky, sometimes running at about the same speed or showing only a mild (comparative to expectations) speedup. This brought into question whether or not the qubits that D-Wave had created were actually functioning like they said they were. The research continued however and has just recently born fruit.

The research, published on ArXiv (not yet peer reviewed), shows that the D-Wave 2X is about 100 million times faster than its simulated counterpart. Additionally for another algorithm, quantum monte carlo, a similar amount of speedup was observed. This is the kind of speedup that the researchers have been looking for and it demonstrates that D-Wave is indeed a quantum device. This research points towards simulated annealing being the best measure with which to judge quantum systems like the D-Wave 2X against, something which will help immensely with future research.

There’s still a long way to go until we have a general purpose quantum computer however research like this is incredibly promising. The team at Google which has been testing this device has come up with numerous improvements they want to make to it and developed systems to make it easier for others to exploit such quantum systems. It’s this kind of fundamental research which will be key to the generalization of this technology and, hopefully, it’s inevitable commercialization. I’m very much looking forward to seeing what the next generation of these systems bring and hope their results are just as encouraging.

electronic-rose

Researchers Create Electric Circuits in Roses.

The blending of organic life and electronics is still very much in its nascent stages. Most of the progress made in this area is thanks to the adaptability of the biological systems we’re integrating with, not so much the technology. However even small progress in this field can have wide reaching ramifications, sometimes enough to dramatically reframe the problem spaces we work in. One such small step has been made recently by a team from the Linköping University in Sweden as they have managed to create working electronic circuits within roses.

electronic-rose

The research, born out of the Laboratory of Organic Electronics division of the university, experimented with ways of integrating electronics into rose plants so they could monitor, and potentially influence, the growth and development of the plant. To do this they looked at infusing the rose with a polymer that, once ingested into the plant, would form a conductive wire. Attempts with many polymers simply resulted in the death of the plant as they either poisoned it or blocked the channels the plant used to carry nutrients. However one polymer, called PEDOT-S:H, was readily taken up by the roses and didn’t cause any damage to the plant. Instead it formed a thin layer within the xylem (one of the nutrient transport mechanisms within plants) that produced a conductive hydrogel wire up to 10cm long.

The researchers then used this wire to create some rudimentary circuits within the plant’s xylem structure. The wire itself, whilst not being an ideal conductor, was surprisingly conducive to current with a contact resistance of 10KΩ. To put that in perspective the resistance of human skin can be up to 10 times more than that. Using this wire as a basis the researchers then went on to create a transistor by connecting source, drain and gate probes. This transistor worked as expected and they went one step further to create logic gates, demonstrating that a NOR gate could be created using the hydrogel wire as the semiconducting medium.

This kind of technology has potential to revolutionize the way that we monitor and influence plant growth and development. Essentially what this allows us to do is create circuitry within living plants, using their own cellular structures as a basis, that can act as sensors or regulators for the various chemical processes that happen within them. Of course there’s still a lot of work to be done in this area, namely modelling the behaviour of this organic circuitry in more depth to ascertain what kind of data we can get and processes we can influence. Suffice to say it should become a very healthy area of research as there are numerous potential applications.

VaccineInfographics11

33% of USA’s 2 Year Olds Not Properly Vaccinated.

Widespread vaccination programs have been the key to driving many crippling diseases to extinction. This boils down to one, simple, irrefutable fact: they work and are incredibly safe. However the anti-vaccination movement, which asserts all sorts of non-scientific dribble, has caused vaccine rates to drop to levels where herd immunity starts to become compromised. This presents a number of challenges as unvaccinated children and adults are not only a threat to themselves but to others who have contact with them. Indeed the problem may be worse than first thought as it appears that even among those who do vaccinate the completion rate is low, with 1 in 3 two year olds in the USA not having completed the recommended vaccination course.

VaccineInfographics11

The study, published RTI International (a non-profit research institute based in North Carolina), showed that up until a child was 2 years old the state of their vaccinations was quite fluid. Indeed the vast majority of children weren’t compliant with the required vaccination schedule with most of them receiving a dose outside the recommended window. Upon reaching approximately 24 months of age however most had caught up with the required schedule although a staggering 33% of them were still non-compliant at this age. This might not seem like much of an issue since the majority do eventually get their vaccinations however there are sound scientific reasons for the scheduling of vaccines. Ignoring them has the potential to limit, or completely negate, their efficacy.

The standard vaccine schedule has been developed to maximise the efficacy of vaccines and also to reduce the risk that, should a child contract that disease, potentially life threatening complications are reduced or eliminated. The pertussis (whooping cough) vaccine is estimated to have an extremely high efficacy rate in young children, up to 95%, but that begins to drop off rapidly if the vaccine is administered later in life. Similar efficacy slopes are seen in other childhood disease vaccines such as the combined MMR vaccine. At the same time these vaccines are administered around the time when the potential impacts of the disease are at their greatest. Missing a vaccine at that point runs the risk of severe complications should the disease be contracted at that point.

It’s unsurprising that the study found that the western states had the lowest rates of vaccination as that’s where the anti-vaccination movement has been most active. Just this year there was an outbreak of measles there and the year before that there was a whooping cough epidemic. Interestingly the southern states had the highest rates of vaccination as shown by the snippet of this infographic above. Whilst the anti-vaccination movement is undeniably an influence in the hodge-podge vaccination approach that seems prevalent the blame here lies solely on the parents who aren’t adhering to the vaccination schedule better.

It’s understandable that some of these things can slip as the challenges of being a parent are unending but when it comes to their health there’s really no other competing priority. For parents this means that they’ll need to pay better attention to their doctor’s advice and ensure that the vaccine schedule is adhered to more closely. Additionally the government could readily help in alleviating this issue by developing better reminder systems, ones that are more in tune with the modern parent’s lives. Hopefully these statistics alone will be enough to jar most into action.

Linear Friction Welding of…Wood?

Friction welding is a fascinating process, able to join dissimilar metals and plastics together with bonds that are far stronger than their welded counterparts. As far as I was aware though it was limited to inorganic materials, mostly because other materials would simply catch fire and not fuse together. As it turns out that’s not the case and recent research has shown that it’s possible to friction weld pieces of wood together in the much the same way as you would metal.

What’s particularly interesting about the process is how similar it is to friction welding of metals or plastics. Essentially the rubbing of the two surfaces together causes the interfaces to form a viscous film that mixes together and, when the friction is stopped, fuse together. For the above video you can see some of the film produced escaping through the sides due to the large amount of pressure that’s applied to ensure the weld is secured. Like all other kinds of friction welding the strength of the joint is dependant on a number of factors such as pressure, period of the friction motion and duration of the weld. As it turns out friction welding of wood is actually an active area of research with lots of investigation into how to create the strongest joints.

Even cooler is the fact that some researchers have developed a technique that allows the welds to be done with no fibres being expelled out the sides. This means that there was no charring of the interface medium, enabling the resulting weld to be even stronger and much more resistant to intrusion by moisture. Whilst you’re not going to see a sub built of friction welded wood any time soon it does mean that, potentially, your house could be built without the use of fasteners or joiners and the first rain that came through wouldn’t make it all come unstuck.

Don’t think you can just go off and rub two pieces of wood together though, the frequency required to fuse the wood was on the order of 150Hz and a pressure of 1.9MPa, far beyond the capabilities of any human to produce. Still it’s not unthinkable that a power tool could be made to do it, although I lack the mechanical engineering experience to figure out how that would be done. I’m sure someone will figure that out though and I can’t wait to see what kind of structures can be made using friction welding techniques.