An important mistake that members of the public seem to make is thinking that what the majority of scientists think, is the truth. An example often given is that most scholars thought the Earth was flat and they were wrong. Despite the fact that no culture past the ancient Greeks has actually thought the Earth was anything other than round (the “fact” that people thought the Earth was flat is itself a myth), the point still remains. What is considered truth today can in fact be proven wrong tomorrow. I think the misconception stems from a mix up between science and philosophy. Most people would probably say that science is what we know and philosophy is what we believe but actually I see it as more sensible to look on these subjects the other way round. In science we a take a hypothesis, a belief (whether we believe it or not), and test to see if it’s right. If evidence supports the hypothesis we hold that idea until solid evidence comes along to disprove it. Philosophy is about logic and reason, the inherent concepts and what we can know to be true based on assumed lemmas. Scientific thought is something that does keep on changing and some of the greatest mistakes in scientific history have been assuming that some previous theories are just too big to question.
On a similar track as yesterday’s post today’s news is about research carried out on liquid crystals. The concept of liquid crystals is that they share properties associated with standard liquids but also solid crystals. For instance they may retain the order and structure similar to a crystal but flow as if they were a fluid. When viewed under a microscope in a polarised light source liquid crystals form some of the most interesting, at least aesthetically, images produced by nature (this is in fact one of the more monochromatic examples and often the images are a lot more vibrant than this):
The metallic structure is quite simple. It can be seen as rows and rows of metal ions in perfect layers being held together by a delocalised electron horde. These layers are what gives metals their particular properties, the malleability for instance is the ability for these layers to slide over each-other and then restrengthen wherever they may end up. Turning pure metals into alloys makes them harder as the different sized metal ions breaks up the easily sliding rows. This is all common knowledge but there is a stage up from a simple metal alloy, that being an amorphous metal (also called a glassy metal). These alloys are so well distributed in particle size their structure is the disorganised layout of glass or concrete, but of course has improved toughness and can conduct electricity unlike both of these materials. However they have gained the unfortunate brittle characteristics especially when under expansive stress which is a considerable problem in modern engineering.
Quite a while ago I wrote a post on materials that are called auxetic. This is where the Poisson ratio, the ratio of how much thinner a material gets when stretched a certain amount, is negative. This means that if you had a rod of auxetic material and you tried stretching it at the ends, it would get thicker in the middle. To the same degree compressing actually makes it get thinner, the opposite of most materials we encounter in every day life. The actual production of auxetic materials, a type of mechanical metamaterial, is actually quite easy with multiple methods being suggested such as moulding, 3D printing and the use of precise incisions into certain regular materials.
The papillary dermis is the uppermost layer of the dermis that lies just below the epidermis of the skin. Of course the outer layers of the skin require constant supplies of blood and other chemicals in order to function properly. The papillary dermis is essential for this role as it is is filled with feeding capillaries and also gives skin its physical properties such as both being stretchy and resilient of damage. The name papillary dermis comes from the Latin for “protrusion” of “nipple” papilla as the papillary dermis has many small finger like protrusions towards and into the epidermal layer. Its these papillae that increase the surface area in contact between the dermis and epidermis and so also assist the transport of soluble molecules in between skin layers.
Some elements are incredibly common and have been studied for hundred of years in one form or another. Abundant elements like oxygen, nitrogen and hydrogen are easy to find as they are literally all around us. Other elements like gold, lead and copper are unreactive and so are easily found lying around most of the time in their elements form or in an easily extractable ore. Elements near the bottom of the periodic table, in the radioactive set, are not only rare as they are constantly decaying but also are quite reactive. The example under examination today is one that most people will have heard of as it is that of plutonium. Samples of plutonium have over recent years been subject to a series of experiments and associated theoretical treatment from X-ray spectroscopy to neutron scattering.
When high temperatures are reached electrons, that are normally held by electromagnetism, are liberated and the gas turns into a plasma. In a similar way, although quarks cannot exist independently (they have to be at least paired with one other quark) when the temperature is raised to 1000 MeV per particle, which is about a hundred trillion (short scale) kelvin, quarks and gluons can be liberated and so exist not confined, but still as a unified mass. This state is normally created through the collision of very heavy nuclei travelling very fast.