It can be seen as a miracle that the approximately 35 trillion cells that make up a human’s body have managed to fit themselves into the right place. All the way when we were a foetus and our form was taking shape the cells had to make sure they were getting into the right positions. It is rare for a brain cell to end up dispersed in the muscle cells or vice versa as the cells are very adept at forming their tissue boundaries. The mechanism that causes such precise delimitation is still quite unclear and so this is considered a prime focus of study in biophysics.
I suppose this will be the last chance to talk about Indonesia as this is technically the last week in which anything to do with it took place. The International Physics Olympiad this year was a marvel to be at and despite some classic British cynicism it was a lovely event. This year was the 50th anniversary of the first Olympiad in Warsaw and to properly close it off I wanted to dedicate this week’s roundup to giving the proper respect to the ideals the IPHO holds. Ultimately something as arbitrary as medals and certificates will be forgotten, as they always are. There will be some people who were fortunate enough to get questions they recognised and some people were unfortunate enough to get apparatus that didn’t work. In twenty years’ time both kinds of people will still have memories and anecdotes to tell about their time in Indonesia and the people they met. Although it has been a long time since I read The Name of the Wind, a quote I half remember is “steel rusts, but music lasts forever.” All the people I talked to had a story to tell and something to teach me and dreams for their future. If I was being poetic I could call these the songs they wished to sing. And for anyone still reading there is one real message I have about the Olympiad in case it wasn’t already clear. The event is not a test with some frivolous socialising thrown in; it is socialising from which students are occasionally pulled to do a test.
Until tomorrow, goodnight.
Perovskite is the name of a mineral of calcium titanium oxide (CaTiO3). The structure of the mineral is shown on the right and any material that shares this structure is also called a perovskite (it should be noted that this is just one of the more common structures but others exist with symmetry below that of the cubic).
Perovskites have found a definite purpose in the world of physics. They demonstrate high efficiency energy conversions along with the ability for artificial versions to be manufactured using thin film production methods. The solar cell efficiencies when constructed with perovskites have improved from about 4% in 2009 to 22% (although the average is still 15%) in 2016 making it the fastest developing solar technology at the current time. One of the main problems presented by perovskite cells, however, is their instability and willingness to decay when exposed to moisture or ultraviolet light (that second one is a pretty big concern for a solar cell).
Superconductivity is a topic talked about often and it is no surprise to see why. Being able to create wires that have literally no resistance to the current flowing through them is an absolutely insane idea. The most recent major discoveries made in the superconducting field was that metal hydrides could be made into superconductors when they were placed under high pressure. The current record for the highest critical temperature is in trihydrogen sulphide (H3S) which became superconducting at 203K provided the conditions were at 200 gigaPascal of pressure.
Desertification is the process where a piece of dry but fertile land progresses to become literally a desert. It is almost exclusively caused by the loss of plant life around the desert border. Without plants to bind the soil it is quickly washed away by rain or more likely blown away in the wind. The nutrients contained in the plants are also lost resulting in nothing but arid sand remaining. Normally these plants are either devoured by grazing animals, chopped away for fire wood or perhaps just simply die off in a drought. The encroaching desert normally has adverse effects towards small groups of natives but there are some areas where the results could be more severe. The Ordos desert in Inner Mongolia (which is actually in China) has severe desertification taking place. Considering that northern China is considered the farming and livestock zone, the progression of previously static sand dunes into the roaming variety has been quite unnerving.
Cancer seems to be almost ever present in today’s society. Every day more things are announced that might cause cancer and various chemicals that are potential cures are discovered. But to this day, the most common thing that can cause cancer, that we run into every single day, is ultraviolet light. Ultraviolet light has a direct photochemical effect on the DNA of humans; catalysing the bonding of two thymine bases (pyrimidines) into either a cyclobutane pyrimidine dimer or a 6-4 photoproduct:
These conversions result in the DNA becoming bent out of shape and hampers the correct reproduction and duplication. Now although the smaller wavelengths of ultraviolet light have greater energy, they are actually completely removed by the Earth’s atmosphere. It is the range of 280 to 400 nanometres that offers the most tangible risk.
The Living With a Star (LWS) program is a project by NASA with the goal of understanding why the Sun varies over time and how this affects the Earth; more specifically, how it affects human life on Earth rather than just general geoastrophysics. The scientific portion of the project began on the 11th of February 2010, when the Solar Dynamics Observatory (SDO) was launched into a geosynchronous orbit. This spacecraft was given the task of taking incredibly detailed readings from the Sun in regards to its magnetic field, corona and solar radiance. To perform this task three separate modules were integrated onto the satellite: The Helioseismic and Magnetic Imager (HMI); the Extreme Ultraviolet Variability Experiment (EVE); and the Atmospheric Imaging Assembly (AIA). Luckily it is just the final one that we need to concern ourselves with today. The AIA unit is most similar to traditional photography being able to take pictures containing the whole Sun in eight different ultraviolet wavelengths and with very high resolutions (4096×4096).