Meteorites, being literally not of this world, show intrinsic differences to rocks found on Earth. Very specifically the ratio of isotopes present in meteors tells us what the isotope ratios were in the places the meteors were likely to form. The difficulty comes in assigning which environment and specifically which star type was likely to have a created the particular proportions of isotopes. A puzzle is created due to the fact that although stars with masses between four and eight times our own sun should have produced a good number of meteorites none have ever been found with confirmed isotope ratios matching these stars. These are the kinds of inconsistencies what plague a physicists mind because it shows that somewhere in the theory a mistake has been made.
Ostwald ripening is a process where particles is a solution (and occasionally a solid) group together over time. This can be the literal particles themselves such as the water droplets in breath or pseudo particles such as bubbles in a liquid. The large particles that exist will always tend to consume their smaller neighbours even if we don’t want them to. To be able to prevent Ostwald ripening from occurring would give us more control over the evolution of a particle system and give us the ability to manipulate the physics metallurgy, biology, topological morphology and the important one for today: foams. As this subject has been studied for over fifty years there have been multiple advancements and some very impressive mathematical models that describe foam’s development such as Lemlich’s model and the von Neumann’s law. Using these models suggestions have been given for how Ostwald ripening could be limited using everything from nanoparticles to external temperature fields but these would only act to slow the collation of the foam and so a new idea was required.
This week there has been some controversy but of two different kinds. Over a year ago I wrote a post about metallic hydrogen which now based on more recent papers seems to be under some scrutiny. Although the research has been peer reviewed some of the experts in the condensed matter have suggested that the observations could have been produced by other factors than the metal hydrogen explanation. It is reasonable to be sceptical as phase V hydrogen has been hunted for for over eighty years although there has yet to be any counter evidence showing the observations were indeed wrong. This puts the whole matter into a semi-true and semi-false zone where the best course is to not think about the situation until more evidence for one side materialises. The other point of contention is based more on ethics than on evidence based science. This is because researchers in California have used the CRISPR gene editing technique (that I have talked about but not by name here) in order to grow animal foetuses that are in fact a combination of the DNA from the base animal and human. The team reports that both a human-pig and human-cow embryos have been developed along with the slightly less eerie mouse-rat. This is done (simplified here) by injecting the undifferentiated cells of a human into the animal embryo and then inserting it into a host mother’s uterus. To add to the concerns the creatures after being created in the embryo form must be, so tastefully put as, “destroyed” after 4 weeks. These animals could be used to grow replacement human organs and could fix the current organ donor hole but I can’t deny I feel mildly disturbed by the concept of growing an animal that contains a large proportion of human cells even if there only purpose is to trick the human immune system.
Until tomorrow, goodnight.
From June to September of every year India come under heavy rainfall often talked about as the Indian summer monsoon. During this time about 90% of the yearly precipitation falls on central India with over 250mm of rain on average falling per month. It is no surprise that this rain is accompanied by the scientifically named “severe thunderstorms.” In the pre-monsoon months these thunderstorms act as a herald bringing thunder, lightening and devastating tornadoes which spread havoc and are rarely predicted with accuracy. Weather of this type is caused by convection currents which are in turn caused by the heating of the land. The swift urbanisation changing farmland to concrete can have acute effects on rainfall and related features.
The autonomic nervous system is a periphery to the standard nervous system that is responsible for controlling the internal organs of the body. It works automatically without instruction (as it would be quite strange to have to will our stomach to digest or our heart to beat) and can be split into two distinct categories, the sympathetic and the parasympathetic nervous systems. It is believed that the parasympathetic nerves are responsible for atrial fibrillation, where the heart begins to beat erratically and at a faster pace with over 10% of people over 80 suffering from it.
When materials receive energy either by incident light or heat some of this energy is given to the electrons and can cause them to be promoted into higher energy levels. These excited electrons are destined to de-excite and return to their original energy level in time. The problem is that in hot metals that have been excited by electromagnetic radiation, the electrons only remain excited for a couple of femtoseconds before relaxing back into a de-excited state. In semiconductors where the bands are much more separated it can be a hundred milliseconds before the electrons revert to their original energy. Ideally we want to be able to control the relaxing mechanism so that the metals are forced to remain excited for a similar length of time as semiconductors. If this could be achieved it would improve our ability to capture solar energy.
Plants and animals are really amazing things considering how intricate they really are. Consider the alveoli in the lungs or microvilli in the intestines, these are both specially designed microstructures perfectly honed to do their job. Hair, skin, and leaves are all serving a purpose ranging from hardy protection from parasites to controlling temperature and reacting to light. It is common for natural materials that evolution has produced to always outclass human made devices, the most famous example being spider web compared to steel. This recent paper has aimed to try and convert some of these surfaces that nature has provided and integrate them into technological devices.