A sad fact about physics is that we are still not really sure about what happens inside the earths crust and mantle and absolutely uncertain about what occurs in the core. We actually know for certain more about the structure of the sun then we do about that of our own planet. This is because we have many ways of analysing the sun from spectroscopy to observation and nuclear modelling. For the earth we have to use mediocre mining depth (the equivalent of putting a scratch on a bowling ball) and the analysis of seismic waves travelling through the planet. A relatively recent discovery in this field was that of low frequency waves that result in “slow earthquakes,” which we still know next to nothing about. A few days ago these waves were observed and we have started to put together a theoretical model of how these earthquakes form. It uses the idea of the borderline between static and kinetic friction in the rock that can cause an elastic movement in the material over a long period so long frequency. More evidence still needs to be collected before the details of this theory can be formed and added to the larger model of the earth and its internal movement.
Black phosphorous is an allotrope of phosphorous that is stable at room temperature unlike it’s brothers. It resembles graphite in many ways as each phosphorous forms three bonds and the overall shape of the allotrope is distorted layer. A key difference is that while graphite is a conductor black phosphorous is only a semiconductor. This similarity to graphite made scientists consider whether a graphene like structure of phosphorous could be formed; in other words just a couple of layers of black phosphorous. Normally this is done by bulk exfoliation, quite literally peeling layers off a lump of black phosphorous. But now a new method has been developed using liquid exfoliation also known as intercalation. This means the liquid is introduced in a way that means it gathers between the layers of black phosphorous and separates them with much greater finesse than simply ripping the layer off. This means that mono-layer black phosphorous formed this way has an almost perfect crystal structure that is extremely useful in the realm of voltaics and microelectronics. The fact that this substance is a semiconductor gives it much greater applicability in circuitry than graphene (which is better for wires) and a new and improved method of producing it is surely a great advancement.
Titanium has been used for quite a long time for implants on the human body, whether this is fillings for someone’s teeth or prosthetic joints. The fact that titanium is light, non-corrosive, durable and non-toxic means that it can be safely and comfortably used without much risk to the patient. But nothing is truly non-corrosive and over a long period of time the titanium can chemically wear into titanium dioxide which can inflame the area around where the implant was placed. Combined with whatever the previous medical condition was this can be very serious yet there has not been many studies into how exactly titanium oxide causes this effect. It turns out that the titanium dioxide forms into anatase, a mineral like form of itself which the bone cells confuse for calcium or phosphorous. This means that the bone cells willingly accept this ion in a mixture of proteins and ions called bio complex leading to a change in behavior of this cell and eventually titanium dioxide poisoning. It is not all negative however as in small doses the titanium oxide changes the function of the cell in a way that could be useful and in fact makes the bone cell return to more juvenile state. This could be used in the future to help human regenerative abilities through the reabsorption of key ions to the bones.
Heisenberg’s uncertainty principle says that ΔxΔp≥ħ/2. In other words the uncertainty in position (x) times the uncertainty in momentum (p) has to be bigger than a really small number, the reduced Planck’s constant over two. Squeezed light is when a set of photons are taken to the limit where ΔxΔp=ħ/2 and can then be used for very precise measurements on the quantum scale; especially mechanical displacement sensing (detecting very small movements). Recently this squeezed light was used measure the pressure that radiation was giving to a mechanical oscillator. Photons of radiation have a momentum and when they are absorbed by a surface that momentum corresponds to a force that causes atomic movement in the oscillator which can then be detected by the squeezed photon probing method. An interesting result of this experiment was that by upping the radiation intensity the pressure exerted completely controlled the the thermal energy in the system and then working backwards the momentum of the squeezed light could be measured. This means that the oscillator can be measured by the non-Huygens light and also measure it in return.
Recently advancements appear to be focused primarily on the realm of astrophysics, primarily space exploration. This week along with the stories I wrote about, another super-luminous galaxy was observed, the brightest ever seen and the discovery of the most distant galaxy ever noticed by the Hubble telescope. Also in a couple of months the William Herschel telescope is going to be upgraded and a piece of equipment will be added that will give it the widest and most detailed spectroscopy range of any of the Issac Newton telescopes (and I think of any land based telescope). I am especially proud as I did some of the mathematics behind this new technology (the health and safety of it) and this upgrade will help bolster the field of observational astronomy. On the topic of observation Richard Feynman famously compared physics to a game of chess between the Gods. We are just spectators and perhaps we can learn a rule or two. We watch pieces in the corners with limited options, we make predictions such as bishops always remaining on their coloured square and see if this holds true. Even when we think we understand the rules of every piece someone can always castle and throw us back into disorder. And even if we did learn every move of the game; we wouldn’t even begin to understand why any particular move was made just as we can’t hope to comprehend a move of Magnus Carlson. Perhaps quantum, electromagnetic, astro, particle, theoretical and nuclear physics are all working together for some massive design like chess pieces aiming for the checkmate but a concept beyond our understanding. Or perhaps they are just patterns our brains are pulling out of the void. Either way, science continues.
The data from the Venus Express mission is just being analysed and reported and an interesting fact has emerged. Just at the end of the mission on the spacecrafts last flyby, the closest to the planet it made, it detected a more linear and less noisy magnetic field. Many planets have magnetic fields but Venus is unique as its atmosphere is weakly conducting causing its magnetic poles to be very chaotic and disorganised. It appears however that this all stops below the ionsophere and the magnetic field becomes very earth-like although quite a bit weaker. Using magnetic fields to understand a planets interior can be very useful although for Venus it is likely that only a lander would be able to use the magnetic fields for scientific research as they deteriorate quickly in the upper atmosphere. The challenge then is to create a lander which can carry the necessary equipment and be able to function on Venus’s perilous surface for long enough. This will be high on the priority list for the next mission to Venus.
Magnetars are neutron stars with extremely powerful magnetic fields surrounding them with strengths of up to 1011 tesla, powerful enough to kill a human from 1000km just by distorting all the electron orbits in every atom in your body. Stars of this kind are now believed to be responsible for super-luminous supernovae a relatively new category of supernovae with a luminosity of between 10 and 150 times a normal blast. The two examples studied were SN 2011kl and ASASSN-15lh supernovae that were observed in 2011 and 2015 respectively. The clue that gave scientists an idea that magnetars might be involved was the fact that both supernovae were accompanied by large gamma ray bursts the first supernovae observed with this feature. Magnetars often give out X-ray and gamma ray bursts and a theory has been developed involving the possibility that if in the formation of a blitazar star (a small star accompanied by a massive gamma ray burst) which often comes from magnetars the neutron star is too big then the super-luminous supernovae occurs. More observations are required however before evidence of this theory can be found to solidify our knowledge of stellar explosions.