A human observer is a person who engages in observation or watches something.

The act of observation

Human subjects observe themselves, each other and the world around them.

  • The act of observation enables us to develop our understanding and engage with the world.
  • When an observer sees something they are engaging in visual perception.
  • An observer can take many forms:
    • A person watching an ocean sunset or the sky at night.
    • A person studying their baby’s face.
    •  A person studying something they can’t see by collecting data from an instrument or machine.
    • A person conducting an experiment in a laboratory.
  • In everyday life, an observer feels themselves to be involved in the things they observe.
  • A scientific observer is someone who causes no unnecessary changes to the object of their observations.
Observing light and colour
  • Our eyes are sensitive to light as a result of the stimulation of photoreceptors embedded within the retinas of our eyes.
  • In the presence of light, an observer perceives colour.
  • The visual experience of colour by an observer is associated with words such as red, blue, yellow, etc.
  • Things appear coloured to an observer because colour corresponds with a property of light that is visible to the human eye.
The subjective experience of colour
  • The perception of colour is a very subjective experience.
  • Factors that determine the particular colour an observer sees include:
    • The environment in which colours are observed, the type of object and colour associations.
    • The colour of nearby objects.
    • The well-being of an observer. Health, medications, mood, emotions or fatigue can all affect the eye, vision and perception.
  • Different observers may see colour differently because of life experience including educational, social and cultural factors.
  • The term observer has distinct and different meanings within the fields of special relativity, general relativity, quantum mechanics, thermodynamics and information theory.