A phenomenon (from Greek φαινόμενoν, pl. φαινόμενα - phenomena) is any observable occurrence.^[1] In popular usage, a phenomenon often refers to an extraordinary event. In physics, a phenomenon may be a feature of matter, energy, or spacetime. For example, Isaac Newton made observations of the phenomenon of the moon's orbit. Additionally, Galileo Galilei made observations of pendulum related phenomena.^[2]

Contents [hide] 1 Use in gemmology 2 Use in philosophy 3 See also 4 References

[edit] Use in gemmology

In gemmology a phenomenon is an unusual optical effect displayed by a gem. Play-of-color, labradorescence, iridescence, adularescence, chatoyancy, asterism, aventurescence, schiller and color change are all phenomena of this type.

[edit] Use in philosophy

In philosophy, the use of the word phenomenon differs from other uses in that it refers to perceived events. Phenomena may be perceived through a person's senses or with their mind.

The term came into its modern philosophical usage through Immanuel Kant, where it is contrasted with noumenon (for which Kant used the term "Ding an sich", or "thing-in-itself") or Absolute. Kant was heavily influenced by Leibniz in this part of his philosophy. Phenomenon and noumenon serve as interrelated technical terms in Kant's philosophy. Noumena, in contrast to phenomena, are not directly accessible to observation. Nowadays, "phenomena" are often, but not always, understood as 'appearances'. These are themselves sometimes understood as involving qualia.

[edit] See also

• Epiphenomenon
• Noema
• Observation
• Phenomenology
• Physical system
• Physicalism

[edit] References

1. ^ New Oxford American Dictionary (2nd ed.)
2. ^ Jeremy Bernstein,