Naïve physics
Encyclopedia
Naïve physics or folk physics is the untrained human perception
of basic physical phenomena. In the field of artificial intelligence
the study of naïve physics
is a part of the effort to formalize the common knowledge of human beings.
Many ideas of folk physics are simplifications, misunderstandings, or misperceptions of well understood phenomena, incapable of giving useful predictions of detailed experiments, or simply are contradicted by more thorough observations. They may sometimes be true, be true in certain limited cases, be true as a good first approximation to a more complex effect, or predict the same effect but misunderstand the underlying mechanism.
Usha Goswami, a professor at the University of Cambridge, defines naïve physics as an intuitive understanding all humans have about objects in the physical world. Cognitive psychologists are delving deeper into these phenomena with promising results. Psychological studies indicate that certain notions of the physical world are innate in all of us.
Smith and Cassati (1994) have reviewed the early history of naive physics, and especially the role of the Italian psychologist Paolo Bozzi
.
The idea that the sun orbits the Earth (the geocentric model
), was also, until about 2000 to 500 years ago, part of mankind's commonsense understanding of the world.
These and similar ideas, in some cases too obvious for anyone to think of questioning them, formed the basis for the first work in formulating and systematizing physics by (for example) Aristotle
and the medieval scholastics
. In the modern science of physics, they were gradually contradicted by the work of Galileo
, Newton
and others. The idea of absolute simultaneity survived until 1905, when the special theory of relativity
and its supporting experiments discredited it.
Research in naïve physics relies on technology to measure eye gaze and reaction time in particular. Through observation, researchers know that infants get bored looking at the same stimulus after a certain amount of time. That boredom is called habituation
. When an infant is sufficiently habituated to a stimulus, he or she will typically look away, alerting the experimenter to his or her boredom. At this point, the experimenter will introduce another stimulus. The infant will then dishabituate by attending to the new stimulus. For both cases, the experimenter measures the time it takes for the infant to habituate to each stimulus.
Researchers infer that the longer the infant takes to habituate to a new stimulus, the more it violates his or her expectations of physical phenomena. When an adult observes an optical illusion that seems physically impossible, he or she will attend to it until it makes sense. Until recently, psychologists believed that our understanding of physical laws emerges strictly from experience. But research shows that infants, who do not yet have such expansive knowledge of the world, have the same extended reaction to events that defy what is physically possible. Such studies conclude that all people are born with an innate ability to understand the physical world.
originally called this concept object permanence
. When Piaget formed his developmental theory in the 1950s, he claimed that object permanence is learned, not innate. Peek-a-boo is a classic example of this phenomenon, and one which obscures true grasp infants have on permanence. To disprove this notion, an experimenter designs an impossible occlusion event, such as the one pictured. The infant is shown a block and a transparent screen. The infant habituates, then a solid panel is placed in front of the objects to block them from view. When the panel is removed, the block is gone, but the screen remains. The infant is confused because the block has disappeared indicating that he/she understands that objects maintain location in space and do not simply disappear.
, one of the psychologists who founded the naïve physics movement, identified the continuity principle, which conveys an understanding that objects exist continuously in time and space. Both occlusion and containment experiments hinge on the continuity principle. In the experiment pictured, the infant is shown a tall cylinder and a tall cylindrical container. The experimenter demonstrates that the tall cylinder fits into the tall container, and the infant is bored by the expected physical
outcome. The experimenter then places the tall cylinder completely into a much shorter cylindrical container, and the impossible event confuses the infant. Extended attention demonstrates the infant’s understanding that containers cannot hold objects that exceed them in height.
published brought innate knowledge to the forefront in psychological research. Her research method centered on the visual preference technique. Baillargeon and her followers studied how infants show preference to one stimulus over another. Experimenters judge preference by the length of time an infant will stare at a stimulus before habituating. Researchers believe that preference indicates the infant’s ability to discriminate between the two events.
Perception
Perception is the process of attaining awareness or understanding of the environment by organizing and interpreting sensory information. All perception involves signals in the nervous system, which in turn result from physical stimulation of the sense organs...
of basic physical phenomena. In the field of artificial intelligence
Artificial intelligence
Artificial intelligence is the intelligence of machines and the branch of computer science that aims to create it. AI textbooks define the field as "the study and design of intelligent agents" where an intelligent agent is a system that perceives its environment and takes actions that maximize its...
the study of naïve physics
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
is a part of the effort to formalize the common knowledge of human beings.
Many ideas of folk physics are simplifications, misunderstandings, or misperceptions of well understood phenomena, incapable of giving useful predictions of detailed experiments, or simply are contradicted by more thorough observations. They may sometimes be true, be true in certain limited cases, be true as a good first approximation to a more complex effect, or predict the same effect but misunderstand the underlying mechanism.
Usha Goswami, a professor at the University of Cambridge, defines naïve physics as an intuitive understanding all humans have about objects in the physical world. Cognitive psychologists are delving deeper into these phenomena with promising results. Psychological studies indicate that certain notions of the physical world are innate in all of us.
Smith and Cassati (1994) have reviewed the early history of naive physics, and especially the role of the Italian psychologist Paolo Bozzi
Paolo Bozzi
Paolo Bozzi, Italian psychologist and philosopher, composer and violin player, was born in Gorizia on May 16, 1930 and died in Bolzano in 2003....
.
Examples
Some examples include:- what goes up must come down
- a dropped object falls straight down
- a solid object cannot pass through another solid object
- a vacuumVacuumIn everyday usage, vacuum is a volume of space that is essentially empty of matter, such that its gaseous pressure is much less than atmospheric pressure. The word comes from the Latin term for "empty". A perfect vacuum would be one with no particles in it at all, which is impossible to achieve in...
sucks things towards it - centrifugal forceCentrifugal forceCentrifugal force can generally be any force directed outward relative to some origin. More particularly, in classical mechanics, the centrifugal force is an outward force which arises when describing the motion of objects in a rotating reference frame...
throws rotating things outwards - an object is either at rest or moving, in an absolute sense
- two events are simultaneous or they are not
The idea that the sun orbits the Earth (the geocentric model
Geocentric model
In astronomy, the geocentric model , is the superseded theory that the Earth is the center of the universe, and that all other objects orbit around it. This geocentric model served as the predominant cosmological system in many ancient civilizations such as ancient Greece...
), was also, until about 2000 to 500 years ago, part of mankind's commonsense understanding of the world.
These and similar ideas, in some cases too obvious for anyone to think of questioning them, formed the basis for the first work in formulating and systematizing physics by (for example) Aristotle
Aristotle
Aristotle was a Greek philosopher and polymath, a student of Plato and teacher of Alexander the Great. His writings cover many subjects, including physics, metaphysics, poetry, theater, music, logic, rhetoric, linguistics, politics, government, ethics, biology, and zoology...
and the medieval scholastics
Scholasticism
Scholasticism is a method of critical thought which dominated teaching by the academics of medieval universities in Europe from about 1100–1500, and a program of employing that method in articulating and defending orthodoxy in an increasingly pluralistic context...
. In the modern science of physics, they were gradually contradicted by the work of Galileo
Galileo Galilei
Galileo Galilei , was an Italian physicist, mathematician, astronomer, and philosopher who played a major role in the Scientific Revolution. His achievements include improvements to the telescope and consequent astronomical observations and support for Copernicanism...
, Newton
Isaac Newton
Sir Isaac Newton PRS was an English physicist, mathematician, astronomer, natural philosopher, alchemist, and theologian, who has been "considered by many to be the greatest and most influential scientist who ever lived."...
and others. The idea of absolute simultaneity survived until 1905, when the special theory of relativity
Special relativity
Special relativity is the physical theory of measurement in an inertial frame of reference proposed in 1905 by Albert Einstein in the paper "On the Electrodynamics of Moving Bodies".It generalizes Galileo's...
and its supporting experiments discredited it.
Psychological Research
As technology becomes more sophisticated, more research on knowledge acquisition is possible. Researchers measure physiological responses like heart rate and eye movement to quantify reaction to a particular stimulus. Concrete physiological data is helpful when observing infant behavior, because infants cannot verbally express their reactions.Research in naïve physics relies on technology to measure eye gaze and reaction time in particular. Through observation, researchers know that infants get bored looking at the same stimulus after a certain amount of time. That boredom is called habituation
Habituation
Habituation can be defined as a process or as a procedure. As a process it is defined as a decrease in an elicited behavior resulting from the repeated presentation of an eliciting stimulus...
. When an infant is sufficiently habituated to a stimulus, he or she will typically look away, alerting the experimenter to his or her boredom. At this point, the experimenter will introduce another stimulus. The infant will then dishabituate by attending to the new stimulus. For both cases, the experimenter measures the time it takes for the infant to habituate to each stimulus.
Researchers infer that the longer the infant takes to habituate to a new stimulus, the more it violates his or her expectations of physical phenomena. When an adult observes an optical illusion that seems physically impossible, he or she will attend to it until it makes sense. Until recently, psychologists believed that our understanding of physical laws emerges strictly from experience. But research shows that infants, who do not yet have such expansive knowledge of the world, have the same extended reaction to events that defy what is physically possible. Such studies conclude that all people are born with an innate ability to understand the physical world.
Types of Experiments
The basic experimental procedure of a study on naïve physics involves three steps: prediction of the infant’s expectation, violation of that expectation, and measurement of the results. As mentioned above, the physically impossible event holds the infant’s attention longer, indicating surprise when expectations are violated.Solidity
An experiment that tests an infant’s knowledge of solidity involves the impossible event of one solid object passing through another. First, the infant is shown a flat, solid square moving from 0˚ to 180˚ in an arch formation. Next, a solid block is placed in the path of the screen, preventing it from completing its full range of motion. The infant habituates to this event, as it is what anyone would expect. Then, the experimenter creates the impossible event, and the solid screen passes through the solid block. The infant is confused by the event and attends longer than in probable event trial.Occlusion
An occlusion event tests the knowledge that an object exists even if it is not immediately visible. Jean PiagetJean Piaget
Jean Piaget was a French-speaking Swiss developmental psychologist and philosopher known for his epistemological studies with children. His theory of cognitive development and epistemological view are together called "genetic epistemology"....
originally called this concept object permanence
Object permanence
Object permanence is the understanding that objects continue to exist even when they cannot be seen, heard, or touched. It is acquired by human infants between 8 and 12 months of age via the process of logical induction to help them develop secondary schemes in their sensori-motor coordination...
. When Piaget formed his developmental theory in the 1950s, he claimed that object permanence is learned, not innate. Peek-a-boo is a classic example of this phenomenon, and one which obscures true grasp infants have on permanence. To disprove this notion, an experimenter designs an impossible occlusion event, such as the one pictured. The infant is shown a block and a transparent screen. The infant habituates, then a solid panel is placed in front of the objects to block them from view. When the panel is removed, the block is gone, but the screen remains. The infant is confused because the block has disappeared indicating that he/she understands that objects maintain location in space and do not simply disappear.
Containment
A containment event tests the infant’s recognition that an object that is bigger than a container cannot fit completely into that container. Elizabeth SpelkeElizabeth Spelke
Elizabeth Shilin Spelke is an American cognitive psychologist at the Department of Psychology of Harvard University and director of the Laboratory for Developmental Studies....
, one of the psychologists who founded the naïve physics movement, identified the continuity principle, which conveys an understanding that objects exist continuously in time and space. Both occlusion and containment experiments hinge on the continuity principle. In the experiment pictured, the infant is shown a tall cylinder and a tall cylindrical container. The experimenter demonstrates that the tall cylinder fits into the tall container, and the infant is bored by the expected physical
outcome. The experimenter then places the tall cylinder completely into a much shorter cylindrical container, and the impossible event confuses the infant. Extended attention demonstrates the infant’s understanding that containers cannot hold objects that exceed them in height.
Baillargeon’s Research
The pivotal findings Renee BaillargeonRenee Baillargeon
Renee Baillargeon is Alumni Distinguished Professor of Psychology at the University of Illinois Urbana-Champaign.-Life:She specializes in the development of cognition in infancy. Baillargeon is perhaps best known for her research that has shown that infants have an intuitive awareness of physical...
published brought innate knowledge to the forefront in psychological research. Her research method centered on the visual preference technique. Baillargeon and her followers studied how infants show preference to one stimulus over another. Experimenters judge preference by the length of time an infant will stare at a stimulus before habituating. Researchers believe that preference indicates the infant’s ability to discriminate between the two events.
See also
- Renee BaillargeonRenee BaillargeonRenee Baillargeon is Alumni Distinguished Professor of Psychology at the University of Illinois Urbana-Champaign.-Life:She specializes in the development of cognition in infancy. Baillargeon is perhaps best known for her research that has shown that infants have an intuitive awareness of physical...
- Elizabeth SpelkeElizabeth SpelkeElizabeth Shilin Spelke is an American cognitive psychologist at the Department of Psychology of Harvard University and director of the Laboratory for Developmental Studies....
- Folk psychologyFolk psychologyFolk psychology is the set of assumptions, constructs, and convictions that makes up the everyday language in which people discuss human psychology...
- Occam's razorOccam's razorOccam's razor, also known as Ockham's razor, and sometimes expressed in Latin as lex parsimoniae , is a principle that generally recommends from among competing hypotheses selecting the one that makes the fewest new assumptions.-Overview:The principle is often summarized as "simpler explanations...
- Weak ontologyWeak ontologyThe term weak ontology has unrelated meanings in computer science and political theory.-Computer science: In computer science, a weak ontology is one that is not sufficiently rigorous to allow software to infer new facts without an intervention by human beings .This distinction does not apply to...
- Common senseCommon senseCommon sense is defined by Merriam-Webster as, "sound and prudent judgment based on a simple perception of the situation or facts." Thus, "common sense" equates to the knowledge and experience which most people already have, or which the person using the term believes that they do or should have...
- Cartoon physicsCartoon physicsCartoon physics is a jocular system of laws of physics that supersedes the normal laws, used in animation for humorous effect. Normal physical laws are referential , but cartoon physics are preferential ....