principle of relativity
Noun: 1. A fundamental postulate in physics: The principle of relativity states that the laws of physics are the same in all inertial frames of reference. This means that no experiment performed entirely within an inertial frame can determine whether that frame is "at rest" or in uniform motion. 2. A cornerstone of modern physics: This principle, when combined with the constancy of the speed of light, forms the foundation of Albert Einstein's theory of special relativity.
The term is used almost exclusively in scientific and academic contexts to discuss the foundational rules governing motion, space, and time in physics. * It is often introduced with the definite article "the" (e.g., the principle of relativity). * It can be specified as the Galilean principle of relativity (pertaining to Newtonian mechanics) or the Einsteinian principle of relativity (pertaining to special relativity).
- The principle of relativity implies that the concept of absolute rest is meaningless.
- Einstein's great insight was to assert that the principle of relativity must also apply to the laws of electromagnetism.
- A key consequence of the principle of relativity is time dilation.
- Galilean principle of relativity: The classical form, applicable to Newtonian mechanics, which states that the laws of motion are the same in all inertial frames. It assumes that time and space are absolute.
- Einstein's principle of relativity (Special relativity): The modern form, which extends the principle to include all laws of physics, including electromagnetism, and is consistent with the constant speed of light in a vacuum. It leads to the relativity of simultaneity, time dilation, and length contraction.
- Relativity (n): The broader theory or concept based on the principle of relativity (e.g., ).
- Special relativity (n): Einstein's theory based on the principle of relativity and the constancy of the speed of light.
- General relativity (n): Einstein's theory of gravitation, which generalizes the principle to include accelerated frames of reference (equivalence principle).
- Relativity postulate: A more technical synonym emphasizing its axiomatic nature.
- First postulate of special relativity: Specifically refers to the principle as one of the two foundational postulates of Einstein's 1905 theory.
- Inertial frame of reference: A key concept required to define the principle; a coordinate system in which a body with zero net force remains at rest or in uniform motion.
- Lorentz invariance: The property that the equations of physics take the same form in all inertial frames, which is a mathematical expression of the principle of relativity.
- Covariance: In physics, the requirement that the form of physical laws is unchanged under transformations between inertial frames.
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(physics) a universal law that states that the laws of mechanics are not affected by a uniform rectilinear motion of the system of coordinates to which they are referred
