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 incapable of giving useful predictions when detailed experiments are made, or simply are contradicted by more thorough observations:

• What goes up must come down.
• When you drop an object, it falls straight towards the core of the planet.
• An object is either at rest or moving, in an absolute sense.
• Two events are simultaneous or they are not.

These and similar ideas, in some cases too obvious for anyone to think of questioning them, were the basis for the first work in formulating physics, e.g., by Aristotle. In the modern science of physics, they were gradually contradicted by the work of Galileo, Newton and others. The final one survived until 1905, when it was debunked by the special theory of relativity.

See also

• Cartoon physics
• Folk mathematics
• Folk psychology
• Occam's Razor
• Weak ontology