The Hadean eon is the earliest geographic eon to exist (unless you count the unofficial Chaotian). It is the time from 4600 million years ago, when the Earth formed, to 4000 million years ago. The name is taken from Hades, god of the underworld in Greek mythology, and probably a fitting choice considering the hellish conditions that existed on Earth at the time. Although we are generally sure that will have been hot, perhaps up to 250°C, and that the atmospheric pressure may have been up to 30 times its current level, the exact atmospheric conditions are still mostly unknown. This mostly because there are very few rocks that even date back this far and so our avenues of study are limited.
Electrons are the most common way for a current to be carried through a solid material. But since flow of charge is synonymous with flow of electrons there are other ways for charge to be transported. Superionic conductors are materials in which the ions are free to move and are also known as solid electrolytes. Being used to transfer ions between electrodes without the need for a liquid to be present is just one of superionic conductors uses. These properties are achieved through the slight cheat that the ion conductors are only partly solid, having some crystalline properties but actually being an intermediate between this and a liquid stage in which the ions can move without hindrance. One of the hopes is that a completely solid lithium battery could be created in which a solid ionic transporter would be a key component.
Most readers will probably be aware of how important stem cells are when it comes to medical research. As they have yet to differentiate they have the possibility of becoming any cell in the body if required, but this great variability comes with an inherent instability. The hematopoietic stem cells in the bone marrow, the cells from which the blood cells can be formed, have the potential to produce leukaemia and other blood cancers. There is also the risk of local tumours spreading their cells into the bone marrow which can result in cancer stem cells and rapid bone metastasis as the skeleton is invaded by the cancer. It is important to understand how the standard and malevolent stem cells interact with each other in the bone marrow so that these conditions can be counteracted and prevented.
A few months ago I wrote this post about using two photon fluorescence to study the capillary system. The basic idea being to use infrared light, which passes through flesh easily, to excite the fluorescent dye but to use the process of two photon absorption so that the remitted photon can be of greater frequency than infrared. Now although this can be done with a chemical dye, there is another option.
This week I was talking to some friends and one of them suggested a very interesting idea which I’ll try my best to convey: In the opening song of the popular Lion King, one of the lines is “more to see than can ever be seen, more to do than can ever be done,” and this is strictly true. There are more things in this world than can ever be understood by one person and of course this is just one world in the colossal black sea of the universe. But to extend the idea a bit further, in the past, when the complete sum of human physics knowledge was relatively small, it may only take a few years of study to be at the cutting edge of research. Now, if you count proper physics education to start in about year 11, it takes nine or ten years to complete a PhD starting there. Is it implausible that at some point in the future it will take a persons full lifetime to reach the edge of human knowledge and they will die just before discovering anything new. Is the technological process of elongating life working faster than we are pushing scientific boundaries (not to mention there are various theoretical caps on life such as brain breakdown into Alzheimer’s, heart failure as it wears out, the probability of cancer from background sources, et cetera).
In a way, its quite a relaxing though to remember that we’ll probably never have to deal with these problems and it’s a bunch of future human’s problems to deal with. Until tomorrow, goodnight.
Of all the molecular ions that exist, by far the least complicated is the dihydrogen cation (H2+) which is just the hydrogen molecule with an electron removed. The H2 only has two electrons in it normally leaving only one when it is turned into an ion. This means that solving the Schrödinger equation can be solved with quite a bit more ease than in most cases with only the quantum mechanics of one electron to consider. Another feature is that the covalent bond that holds the hydrogens together is only composed of one electron.
Over the last couple of decades the possibilities of what additive manufacture, more commonly known as 3D printing, can achieve has spread into the medical, aerospace and military industries. The most effective way of performing these processes for metals would be power bed fusion. This is where a layer of the metal powder, less than a fifth of a millimetre thick, is distributed in the correct shape. A laser fuses this powder together and second layer is applied. This continues until the design is realised. For more detail I strongly recommend looking here at this page made by Loughborough University which goes into a lot more of the details.