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Observation basically means watching something and taking note of anything it does. For instance, you might observe a bird flying by watching it closely. The sciences of biology and astronomy have their historical basis in observations by amateurs. There is pleasure in observation, which explains the participation of hobbyists.

Table of contents
1 The role of Observation in the Scientific Method
2 Hobbies that involve observation

The role of Observation in the Scientific Method

The scientific method includes the following steps:

  1. 'observe' a phenomenon,
  2. 'guess' an explanation for the phenomenon,
  3. 'predict' a logical consequence of the guess,
  4. 'test' for the prediction, and
  5. 'review' for any mistakes.

Observation takes place in the first and fourth steps.

Example: The Big Bang

In cosmology, the original observation was that we seem to live in a firmament. The sun seemed to rise and set, travelling on a huge transparent bowl which was set around our world. Various paradigms which explained our world, came and went, but the universe seemed static. Even Einstein believed this.

Observation: Hubble's redshift

In the 1920s Edwin Hubble of Mount Wilson observatory [1], observed that the galaxies, on the whole, were moving away from each other. Thus we live in an 'expanding universe'. The speed of expansion was apparently constant (Hubble's 'constant'), as evidenced by light from the galaxies, which was doppler-shifted in color toward the red side of the spectrum.

Einstein correspondingly modified his field equation. See Cosmological constant

Hypothesis about the abundance of the elements

If the universe is expanding, then it must have been much smaller and therefore hotter and denser in the past. George Gamow hypothesized that the abundance of the elements in the Periodic Table of the Elements, might be accounted for by nuclear reactions in a hot dense universe. He was disputed by Fred Hoyle, who invented the term 'Big Bang' to disparage it. Fermi and others noted that this process would have stopped after only the light elements were created, and thus did not account for the abundance of heavier elements.

Gamow's prediction: One consequence of this hypothesis was a 5 - 10 Kelvin blackbody radiation temperature for the universe, after it cooled during the expansion.

Observation: the microwave background

In 1965, Arno A. Penzias and Robert W. Wilson announced that microwave radiation was surrounding us in all directions, at a level which was of the order of magnitude predicted by Gamow. Penzias and Wilson got the Nobel Prize for this discovery.

Big Bang Hypothesis now corroborated

After this piece of evidence, Gamow's hypothesis was now more likely. The age of the universe is currently estimated to be 13.7 billion years after the Big Bang.

Current observations

More refined measurements, such as those from the COBE satellite, are best fit by radiation from a pure 2.7 Kelvin blackbody.

Reference: J.A. Peacock, A.F. Heavens, A.T. Davies (eds.), 1989. Physics of the Early Universe. Proceedings of the 36th Scottish Universities Summer School in Physics (SUSSP). ISBN 0905945190.

Hobbies that involve observation

Hobbies that involve observation depend for their interest on items being observed. A knowledge of these items and their habitats will develop over time in the observer, who may draw upon the experiences of others as conveyed in books or websites or by word of mouth. Most such hobbies involve classification of the items seen, with the precision and reliability of such classifications generally increasing over time. Depending on the geographic dispersal of the creatures or things being observed, pursuit of the hobby might well require or entice travel. When spotting natural creatures, an understanding of their migration patterns may be essential. Specific creatures may only be visible in particular places at certain times of the year.

There are parallels in those hobbies relating to man-made items. International political events may sometimes generate a gathering of VIP aircraft, and an international football match may cause a sudden influx of charter airliners to the region where the match is played.

There is likely to be a social aspect to such hobbies, since fellow enthusiasts will normally alert a hobbyist to forthcoming (or even current) opportunities to witness unusual items within the scope of the shared pastime. New technologies such as mobile telephones and the Internet have clearly increased the opportunities for passing such information between fellow enthusiasts when it is timely.

See also: amateur astronomy, birdwatching, and train spotting.