Why is the sky blue? Why are sumo wrestlers so fat? How does the chicken cross the road with so much traffic?
The answers of many questions that trouble us can be found by doing first hand investigations. In science, first hand investigations allow scientists to discover new things and explain old things. Through these, they are able to form hypothesises, models, experiments, theories and even laws.
First, when observations are made, hypothesises are formed. To test these hypothesises scientists conduct experiments. If their hypothesis is right, it is confirmed by further experiments and validated by other scientists. After many experiments and confirmations, a theory is formed. A scientific theory is a broad and general idea or explanation provided by scientists and is related to observations and is supported by a large amount of evidence. A theory is not a fact however it is just a possible explanation. An example of a theory is the Big Bang Theory.
A theory can lead to the development of a model which provides a visual representation and explanation of the scientists’ understanding. A model can assist in predicting what could happen if a particular incident occurs. An example of a model is the Niels Bohr model of the atom.
Further research is conducted to test the theory and the model. As advances in technology occur, more information can be obtained and so the theories and models can then be altered. If the model or theory seems to hold true in numerous areas of science, a scientific law is formed. These laws provide a greater level of understanding and explain why many things happen. An example of a law is Sir Isaac Newton’s law of Inertia.
In Biology, first hand investigations in the form of field studies are conducted to estimate the abundance and distribution of animals in an ecosystem. Different techniques are used for animals and plants because of their rate of movement. For plants, the percentage cover method is used to estimate their population. Quadrats (1m x 1m squares) are used to cover randomly selected areas in a region. The number of organisms per quadrat is then averaged. The total area of the region is divided by the size of the quadrat and then multiplied by the number of organisms per quadrat. This method does not work for animals because of their constant seasonal movement. Rather, for animals, the capture-recapture method is used. In this, animals are captured, tagged, released and recaptured after a given time; the number of tagged individuals in the recaptured sample is then counted and the abundance of the animals is thus calculated.
To calculate the distribution of an organism, biologists use transects. A transect is a narrow strip that crosses the area being studied from one side to the other. They are used mainly in large areas but can also be used in small ponds to estimate the distribution of smaller plants and slow animals. It is difficult to observe the distribution of most animals due to their seasonal...