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Nine Critical Sensations

Outline

Physics and Sensation

A physics student on a pilgrimage to explore the limits of perception, from a 19th century woodcut by an unknown artist.
A physics student crawling under the sky’s edge to reach out into the Empyrean. From Camille Flammarion’s book, L’Atmosphère – Météorologie Populaire. Paris, 1888.

Sensation is the conscious awareness of feeling, hearing, seeing and tasting our surroundings. And at EthnoPhysics, we start with the idea that theoretical physics can be understood as a description of these sensory perceptions. This approach is not radical. A central concept in science is that evidence must be empirical and that theories are linked to observation. So it is certainly reasonable to methodically consider surrounding sensations.

But actually starting a presentation of physics this way may fit awkwardly with some commonly held views. In fact, most presentations of mechanics start with mysteriously received notions of length, time and mass. For example, a textbook that has been well-used for the last 80 years, Goldstein’s Classical Mechanics, begins by saying “they will be assumed as undefined terms whose meanings are familiar to the reader”.1Herbert Goldstein, Classical Mechanics, page 1. Addison-Wesley Publishing Company, second edition, 1980. Traditionally, students are just supposed to understand length, time and mass before they start class. This website aims to present a logically ordered, easy-to-teach account of these fundamental concepts.

There is also another important result that comes from a rigorous analysis of sensation. By putting the scientific horse in front of the cart, we are also able to develop a mathematically simple theory that accurately summarizes decades of hard-won experimental data about nuclear particles. So EthnoPhysics can be further tested in our laboratories. These developments have been strongly influenced by Ernst Mach.

Ernst Mach and the Analysis of Sensation

Empirical evidence establishes the foundation of science.  And according to the Austrian scientist and philosopher Ernst Mach the goal of physical theory is to express the observed facts as simply and economically as possible.

Mach held that scientific laws are summaries of experimental observations, constructed so that humans can accurately describe and understand complicated experiences. He influenced Albert Einstein and the development of relativity. Here is an unusual self-portrait from a good teacher, and a few favourite quotes.2Ernst Mach, The Analysis of Sensations and the Relation of the Physical to the Psychical, pages 2, 6 and 19. Translated by C. M. Williams and Sydney Waterlow.  The Open Court Publishing Company, Chicago and London, 1914.

An icon indicating a quotation.Colors, sounds, temperatures, pressures, spaces, times and so forth, are connected with one another in manifold ways; and with them are associated dispositions of mind, feelings, and volitions. Out of this fabric, that which is relatively more fixed and permanent stands prominently forth, engraves itself on the memory, and expresses itself in language.

An icon indicating a quotation.… I lie upon my sofa. If I close my right eye, the picture represented in the accompanying cut is presented to my left eye. In a frame formed by the ridge of my eyebrow, by my nose, and by my moustache, appears a part of my body, so far as visible, with its environment.

Sensation is analyzed by Ernst Mach to explain the laws of physics.
Figure one from The Analysis of Sensation, by Ernst Mach, 1897.

Thus Mach identifies a pathway to knowledge as an analysis of sensory experience using language. He honestly shows that he himself is part of the question. And then he mentions a confusing issue.

An icon indicating a quotation.The useful habit of designating such relatively permanent compounds by single names, and of apprehending them by single thoughts, without going to the trouble each time of an analysis of their component parts, is apt to come into strange conflict with the tendency to isolate the component parts.

So for clarity, we are going to presume that almost all humans share several well-known experiences that are called reference sensations.  Then, as the theory of EthnoPhysics is presented, ideas are hyperlinked back to these common perceptions. This way we can easily click for semantic refreshment, and hopefully avoid “strange conflict” in subsequent analysis. Next, we take a closer look a these fundamental references.

Reference Sensations

For a methodical discussion we identify several reference experiences drawn from everyday life.  Reference sensations are standards from which all perceptions are judged and recognized.  These familiar perceptions are mathematically represented by numbers called constants . They are visually represented using the icons in the following table.   You can click on these icons for more detail, here and in other articles too.

An icon for visual sensations that are greyish or achromatic. Seeing the Sun
An icon for visual sensations that are reddish or greenish. Seeing Blood
An icon for visual sensations that are yellowish or bluish. Seeing Gold
An icon for warm or burning sensations. Touching Steam
An icon for cool or freezing sensations. Touching Ice
An icon for somatic sensations. Hearing a Heartbeat
An icon for taste sensations that are lemon flavored. Tasting a Lemon
An icon for taste sensations that are like the flavor of the ocean. Tasting the Ocean
An icon for taste sensations that are honey flavored. Tasting Honey
An icon for the sensation of touching the earth. Touching the Earth

The foregoing list of reference sensations includes seeing blood. Does that seem too crude? Well, please consider this little story: Julius von Mayer was a 19th century German physician who did the first calculations linking heat and motion. His scientific thinking was guided by careful observations he made during the medical practice of bloodletting . This happened while he was the doctor for a Dutch three-masted sailing ship on a voyage through the Southeast Asian archipelago.

Reference sensations are exemplified by this photo of a bleeding finger showing the colour red.

He reported, “In the summer of 1840, in the course of the bloodlettings I undertook in Java on recently arrived Europeans, I made the observation that the blood taken from the vein in the arm showed almost without exception a startlingly bright red coloration.”3Kenneth Caneva, Robert Mayer and the Conservation of Energy, page 236. Princeton University Press, 1993.

This surprising visual experience was combined with his analysis of climate, body heat and respiration to deduce a law for the conservation of energy. By 1842, Mayer had described the vital chemical process now referred to as oxidation as the primary source of energy for any living creature. Thus Mayer became a founder of modern thermodynamics. And today his story sparks our use of reference sensations – like seeing blood – to parse human experience into several classes of sensation.

Classes of Sensation

EthnoPhysics begins by sorting experience into various classes.  The full gamut of human perception is wildly varied, some phenomena forever dancing beyond the grasp of language and mathematics. But even a rudimenary account can be very valuable. So let’s start crudely dividing perceptions into a handful of categories. Definitions are fuzzy. There may be gaps and overlaps. But starting from this oversimplification we progressively add more detail and refinement until we can ultimately communicate with precision and accuracy about our perceptions.

Classes of SensationExamples
Visual Sensations
Any vision, sight or ocular experience that could loosely be described as grayish is called an achromatic visual sensation. Any sight that could be roughly described as reddish or greenish is called an organic chromatic sensation. And any image that could be described as yellowish or bluish is called an inorganic chromatic visual sensation.
An icon for visual sensations that are greyish or achromatic.
An icon for visual sensations that are reddish or greenish.
An icon for visual sensations that are yellowish or bluish.
Achromatic


Organic


Inorganic
Thermal Sensations
Strong feelings that are so hot or cold that they are hazardous are called dangerous thermal sensations. Warm or cool feelings that happen during routine human activity are called safe thermal sensations.
An icon for warm or cool sensations.
An icon for burning or freezing sensations.
Safe


Dangerous
Somatic Sensations
Any tactile or auditory perception associated with a sense of touch, pressure, hearing or sound is called a somatic sensation.
An icon for somatic sensations.Somatic
Taste Sensations
Flavors or gustatory perceptions that are produced when a substance in the mouth reacts with nerves of the tongue and palate are called taste sensations. We specifically consider sweet, sour and salty flavors. But bitter, pungent and metallic tastes are other well-known examples from among hundreds of distinctly recognizable flavors.
An icon for taste sensations that are lemon flavored.
An icon for taste sensations that are like the flavor of the ocean.
An icon for taste sensations that are honey flavored.
Sour


Salty


Sweet
Other Sensations
Smells, odors and olfactory perceptions. Balance and related kinesthetic senses. Animalistic perceptions like echo-location or sensitivity to the Earth's magnetic field. Telepathy, clairvoyance and paranormal abilities. A sense of humor. An eye for beauty. Feeling the weight of injustice. Miracles, memories, hallucinations and dreams. The look of love …

Next we make some assumptions.  The first hypothesis is that physics and chemistry are based on describing just nine distinct classes of sensation, i.e. the ones with icons in the table above.  Other genres of description are certainly possible, and any system is discretionary.  For example, different cultures may use different color terms to describe the same visual stimulus.  Moreover, any categorical system also introduces a bias by oversimplifying and truncating the number of primary distinctions. For example, the sensation of orangeness cannot be fundamentally grasped by a system that only recognizes yellow and red as elementary sensations.

Nonetheless, it is possible to understand a lot of physics and chemistry using just nine categories. Less than nine leads to oversimplification, loss of detail and ultimately a loss of usefulness. More than nine allows for more descriptive subtlety, with the cost of more messy complexity. So for simple accounting and practical reporting we use nine classes of sensation along with binary descriptions.

Binary Descriptions of Sensation

If a survey of some class of sensation is made more exact by subdivision into two mutually exclusive parts, then we are making a binary description of the experience. All detail and subtlety are reduced to just two possibilities. This simplifies accounting and reporting. The notion that theoretical physics can be understood using this binary style of analysis was suggested by Anaxagoras of Clazomenae about 2,500 years ago. Accordingly, we use the following specialized vocabulary to make binary descriptions.

Black or White

Binary descriptions of grayish sensations are illustrated by this icon for screen brightness.

Any vision, sight or ocular experience that could loosely be described as greyish is called an achromatic visual sensation. Words like grey, black, white, dark, bright, silvery, taupe, leaden, ecru, ashen, beige, pale etc. are used to convey greyish impressions. The reference experience for this class is seeing the Sun. So to make a binary description of a greyish visual sensation compare it to seeing the Sun. Report the result as either black or white.

Red or Green

Redness is illustrated by this image of a drop of blood.

Any sight that could be roughly described as reddish or greenish is called an organic chromatic sensation. We use words like red, green, pink, chartreuse, crimson, turquoise, orange, purple, olive, scarlet, khaki, magenta etc. to identify particular visual sensations within the organic category. Ewald Hering reports that, “No colour is clearly reddish as well as greenish … redness and greenness … are mutually exclusive.”4Ewald Hering, Outlines of a Theory of the Light Sense, page 49. Translated by Leo M. Hurvich and Dorothea Jameson.   Harvard University Press, 1964. Therefore organic visual sensations are capable of binary description. 

The reference experience for describing this class is seeing blood.   So to make a binary description of an organic chromatic sensation, compare it to seeing blood. Report the result as either red or green.

Yellow or Blue

Yellowness is illustrated by this image of golden coins.

Any sight that could be described as yellowish or bluish is called an inorganic chromatic visual sensation. We use words like yellow, blue, gold, cyan, indigo, brown, orange, violet, turquoise, chartreuse, azure, ocher, cerulean, sepia etc. to identify particular colors within the inorganic category. Ewald Hering reports that, “no color is both yellowish and bluish … yellowness and blueness are mutually exclusive.”5Ewald Hering, Outlines of a Theory of the Light Sense, page 49. Translated by Leo M. Hurvich and Dorothea Jameson.   Harvard University Press, 1964. Therefore inorganic visual sensations are susceptible of binary description.

The reference experience for this class is seeing gold. So to make a binary description of an inorganic chromatic sensation, compare it to seeing gold. Report the result as either yellow or blue.

Warm or Cool

Warmness is illustrated by this icon for a steaming pot of food.

Any mild perception of heat that happens in routine human activity is called a safe thermal sensation. Safe thermal sensations are described using words like warm, cool, balmy, chilly and lukewarm. They are similar to the temperature of a living person. The reference experience for this class is touching steam . So to make a binary description of a safe thermal sensation, compare it to touching steam. Report the result as either warm or cool.

Freezing or Burning

Coldness is illustrated by this icon for a snowflake.

Any hazardous perceptions of heat or cold are called dangerous thermal sensations. We use words like icy, boiling, freezing, scorching, frosty and blistering to describe these sensations. They are not like touching a living person, temperatures are significantly higher or lower. The reference experience for this class is touching ice . So to make a binary description of a dangerous thermal sensation, compare it to touching ice. Report the result as either freezing or burning.

Left or Right

Hearing a heartbeat is suggested by this icon of a vibrating heart.

Any corporeal perception associated with a sense of pressure, hearing or touch is called a somatic sensation. Somatic sensations are described using words like hard, soft, loud, quiet, slap, tickle, push, pull, scream, whisper, port, starboard, bass, treble and so on. The reference experience for describing this class is hearing a heartbeat. So to make a binary description of a somatic sensation, compare it to hearing a human heartbeat. Report the result as felt on either the left side or the right side.

Tart or Soapy

Sourness is illustrated by this yucky icon for taste sensations that are lemon flavoured.

Any flavor or gustatory perception that could be roughly described as acidic or caustic is called a sour taste sensation. We use words like soapy, tart, corrosive, sharp, astringent, tangy, acerbic, rancid, vitriolic, biting, vinegary etc. to identify these flavors. The reference experience for describing this class is tasting a lemon. So to make a binary description of a sour sensation compare it to tasting a lemon. Report the result as either tart or soapy.

Brackish or Potable

Saltiness is illustrated by this waves icon for taste sensations that are like the flavour of the ocean.

Any flavor or gustatory perception that could be loosely described as something like drinking water is called a moist sensation. We use words like briny, fresh, pickled, pure, fishy, drinkable, alkaline, clean, saline, etc. to describe specific tastes in this category. The reference experience for this class is tasting the ocean. So to make a binary description of a moist taste sensation, compare it with a sip of seawater. Report the result as either brackish or potable.

Sugary or Savory

Binary descriptions of sweet sensations are illustrated by this happy-face icon.

Any flavour or gustatory perception that could be vaguely described as something like tasting honey is called a sweet sensation. We use words like yummy, sugary, umami, caramelly, savory, candied, spicy, brothy, glazed, meaty, syrupy etc. to describe these flavours. We make binary descriptions of sweet sensations by comparing them with other sensations, and historically the great pioneers of chemistry almost killed themselves by direct contact with their discoveries. Now testing supersedes tasting, so instead we often perform laboratory experiments to decide if a flavor is sugary or savory. But this distinction may be perceived directly in the flavour difference between, for example, spearmint leaves and caraway seeds.

Next

EthnoPhysics faviconMemorable Events

Simple events are defined from eighteen common, but distinct sensations. Chains of events are easy to remember if they are repeated.
References
1Herbert Goldstein, Classical Mechanics, page 1. Addison-Wesley Publishing Company, second edition, 1980.
2Ernst Mach, The Analysis of Sensations and the Relation of the Physical to the Psychical, pages 2, 6 and 19. Translated by C. M. Williams and Sydney Waterlow.  The Open Court Publishing Company, Chicago and London, 1914.
3Kenneth Caneva, Robert Mayer and the Conservation of Energy, page 236. Princeton University Press, 1993.
4, 5Ewald Hering, Outlines of a Theory of the Light Sense, page 49. Translated by Leo M. Hurvich and Dorothea Jameson.   Harvard University Press, 1964.