Friday, January 30, 2009
GEOG LESSON! 30.1.09
This is basically a miniature version of the mindmap Mr Heah wrote on the board (:
So this lesson, we were taught how to answer questions like the one above "How is the atmosphere essential to life", topics which are very broad and require lots of compressing. So it goes like this:1. Remember only relevant and important knowledge from the provided readings and text. Most of the stuff above is general knowledge, so no need to get into technical details.
2. Organise relevant information into a mindmap, like the one above. Keep the points simple and direct. Placard mugging is highly discouraged.
3. Length of answers should be directly proportionate to the number of points of the question. Therefore, no essays for 5 mark questions.
We watched a documentary later on, and I shall try my best to summarise its main points.
1. The atmosphere is made up of the four main layers, each with its own properties that makes it a protective and life-giving shield. A general summary can be found in the mindmap.
2. The atmosphere is a fluid, not a layer of random gases. This was illustrated by the cool 'wind'surfing guy, and the rock formations caused by wind and sand. (Apparantly, the weight of the atmosphere is pushing down on us, 13 pounds per square inch)
3. The gases in the troposphere enables us to carry out life processes, mainly referring to Oxygen and Carbon dioxide, which we need for respiration and heat retention respectively. And the lack of oxygen leads to miscarriages O.o
4. The history of the atmosphere was also explained, tracing back to 4.4 billion years ago, when the gases escaped from the volcanic material on earth. The earth was rich in carbon dioxide and other greenhouse gases, causing bacterial organisms to thrive. Later on, the oxygen they produced in large quantites enabled us to evolve.
5. As the Global Warming issue was raised at the end, and they revealed a shocking revelation that the Carbon dioxide problem was not as serious as the methane problem! Many tonnes of methane (which is a lethal greenhouse gas) are trapped in permafrost in the freezing regions of the earth, and global warming is causing the release of this gas!
We will most probably end up like the bacterium anyways (:
Just as a note (to fulfil the conditions of the blog assignment), I feel that the mindmap part of the lesson was the most important part, although the Stewart person was beneficial too.
Well, that's it! Cindy (:
Monday, January 19, 2009
Reflection
During today's lesson. We learnt about structure and composition of atmosphere. Generally it is made up of 78% of nitrogen , 21% of oxygen and 1% of other gases like carbon dioxide and water vapor, etc. And the reason why atmosphere is essential to life is because it exerts a suitable pressure, provide oxygen which is essential for life and shielding us from sheer heat from the sun, enable sunlight to go through it and thus plants will undergo photosynthesis and provide food for us.Chen Xingru