This has been a very interesting week. The post on Monday, Studying Skin Atrophy With Age, got me thinking about the very concept of ageing. Over the years humanity has become blighted by diseases that our ancestors never had to deal with. Diseases like dementia were unheard of back when we lived in caves for the simple fact that humans live past 40. We could always be relied on to die of injury and infection long before our bodies failed. When we became technologically evolved and begun living past our natural lifespan, our genetics kind of give up and admitted to not know what they’re supposed to be doing at this age. This is of course the natural result of people only needing to live long enough to reproduce according to evolutions view. Resistance to dementia isn’t a trait that will be passed on if you’re not having children at that age.
On some level, this provides a hard limit on how long a human can live (at the moment). The human mind simply won’t survive until age 200 without beginning to break down. This is the inevitable result of technological evolution overtaking actual evolution. We now live in completely artificial environments. When the only grass and trees that remain in an area are those that we permit (and more than likely were planted) then you can see that most modern day humans in the developed world live a life completely separate to the wild. It is of no surprise then that we live long enough for our organs to fail which could be ironically seen as an “unnatural death” in evolutionary terms.
It is an interesting thought, that medical technology will always run into some biological limit and there may be no way to exceed this except by changing our very biology itself. A concept that’s probably worth some thought, until tomorrow, goodnight.
Pistol shrimp. Even if the name isn’t familiar there is a good chance you will have heard of this special shrimp (more technically known as alpheidae family of snapping shrimp). Rather that the regular catching and grappling mechanisms that shrimp can use to defend and attack, the pistol shrimp has been granted a special ability. Their claws are asymmetric and the larger of the two can be slammed shut to create a large snapping sound. Anyone who hasn’t heard of this shrimp will probably be thinking “so what?” This sound makes the shrimp a contender for the loudest creature in the sea. The snap creates a bubble which collapses under the water pressure. Getting hit by this collapsing bubble which can be thrown 4 cm from the shrimp’s claw; travels 60 miles per hour; is under an acoustic pressure 80 kPa; and probably reaches a temperature of 5000K spells the end for any small sea creature caught in the way and a hefty stun for anything bigger.
The image on the left represents what is known as Von Neumann architecture, a layout for the various main component blocks of a computer. There is an input to receive a value; a central processing unit for calculations; a memory unit to store data and instructions; and finally an output so that we can receive the meaningful result of the input. This is one of the most common architectures for a computer to take (with a bit of streamlining and improvement; there was always the risk of data being run as code which is luckily prevented now). As computers have developed we have begun reaching a plateau of power and performance which we may not be able to overcome while still using Von Neumann architecture.
The diagram on the right represents a form of aquatic carbon cycle. It can be seen that dissolving is not the only way carbon dioxide enters the sea and the carbon that does enter this way will not progress to one of the more permanent carbon stores such as the handily suggested calcium carbonate (CaCO3). For carbon dioxide to be converted into such a form the left hand arrows provide the processes being either anorganic or organic. This paper looks at the biological pumping mechanism of carbon into the deep sea and how the rate of this transport is affected by other chemicals and ions nearby.
Although precipitation is often used as a synonym for rain, it is also the antonym of dissolving. As a material dissolves into a solution and appears to disappear it can likewise emerge from a solute when the conditions change to make the solid form more energetically stable. This is precipitation. Deserts suffer from an unfortunate form of precipitation where water is pulled from deep underground by capillary action. As it moves upwards it dissolves salts witch are carried with it to the surface. As the water evaporates the salt ions precipitate back into salt and leave a highly inhospitable layer upon the desert surface.