Processes operating in the Earth system take place on spatial scales varying from fractions of millimeters to thousands of kilometers, and on time scales that range from milliseconds to billions of years.
<span>Examples of instantaneous - breathing; rotation of the Earth; earthquake<span>Examples of long term - making coal; plate tectonics</span></span>
Catastrophism is the theory that the Earth has largely been shaped by sudden, short-lived, violent events, possibly worldwide in scope.[1] This is in contrast to uniformitarianism (sometimes described as gradualism), in which slow incremental changes, such as erosion, created all the Earth's geological features. The proponents of uniformitarianism held that the present was the key to the past, and that all geological processes (such as erosion) throughout the past were like those that can be observed now. Since the early disputes, a more inclusive and integrated view of geologic events has developed, in which the scientific consensus accepts that there were some catastrophic events in the geologic past, but these were explicable as extreme examples of natural processes which can occur.
The plasma membrane of axon is called axolemma. The potassium and sodium leak channels leak the sodium and potassium ions inside the cell respectively. The leak channels provide the constant movement of ions across the membrane. Potassium and sodium ions are positively charged, thus entry of positively charged ions inside the cell makes the cell more positively charged than the environment outside the cell. The environment outside the cell becomes more negatively charged. This leads in the negative membrane potential of axolemma.
