A human observer is a person who engages in observation or watches something.
- Humans observe themselves, each other and the world around them.
- The act of observation allows us to develop our understanding of ourselves and interact 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 a 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 setting.
- In everyday life, an observer feels involved in the things they observe.
- Observers can have biases and subjective interpretations, which may affect their observations.
- A scientific observer is someone who avoids making unnecessary changes to the object of their observations.
About the observation of colour
- The human eye is sensitive to the visible spectrum, which consists of spectral colours ranging from approximately 400 to 700 nanometers.
- The eye’s sensitivity to the visible spectrum allows us to perceive colours when light interacts with objects.
- The visual experience of colour by an observer is associated with words such as red, blue, yellow, etc., which are typically used to describe hue or dominant wavelength.
- The colour an observer sees depends on:
- The wavelengths of visible light present in the environment.
- The wavelengths absorbed, transmitted, or reflected by an object or medium.
- The perception of colour can be affected by factors such as brightness, contrast, and saturation, which are related to the amount of light present in a stimulus and its interaction with the eye and brain.
- The observed colour of light is determined by its wavelength, not its frequency. But as light travels from one medium to another, such as from air to glass, the colour seen by an observer may change because refraction disperses colours in different directions.
About the subjective experience of colour
- The perception of colour is a very subjective experience.
- Factors that determine the particular colour an observer sees include:
- 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.
About the perception of colour
- The perception of colour is a very subjective experience.
- The colour of nearby objects can influence the perception of colour.
- The environment in which colours are observed and the type of object can influence colour perception.
- The physical properties of light, including wavelength and intensity, can affect how colours are perceived.
- An observer’s physical and mental state can affect their perception of colour. Health, medications, mood, emotions or fatigue can all affect an observer’s eyes, vision and perception.
- Different observers may perceive colours differently based on their life experiences, linguistic backgrounds and educational, social, and cultural factors.
- The term observer has distinct meanings in various scientific fields such as special relativity, general relativity, quantum mechanics, thermodynamics, and information theory.
Related diagrams
Each diagram below can be viewed on its own page with a full explanation.
References
A human observer is a person who engages in observation by watching things.
- In the presence of visible light, an observer perceives colour because the retina at the back of the human eye is sensitive to wavelengths of light that fall within the visible part of the electromagnetic spectrum.
- The visual experience of colour is associated with words such as red, blue, yellow, etc.
- The retina’s response to visible light can be fully described in terms of wavelength, frequency and brightness.
- Other properties of the world around us must be inferred from patterns of light.