crookes radiometer
Definition
- Noun:
- A scientific instrument: The Crookes radiometer is a device that demonstrates the conversion of light energy into mechanical motion. It consists of a glass bulb containing a partial vacuum, inside which a set of vanes (small paddles or blades) are mounted on a spindle. When exposed to light, particularly sunlight or strong artificial light, the vanes rotate.
Usage
- The Crookes radiometer is often used as a decorative scientific demonstration piece.
- It is placed in a well-lit area, such as a windowsill, to observe its operation.
- Example:
Advanced Usage
- Scientific Principle: The rotation is primarily caused by a combination of effects: the transfer of momentum from light photons (radiation pressure) and the movement of gas molecules from the warmer (darkened) side of the vanes to the cooler (lighter) side (thermal transpiration or thermal creep).
- Common Misconception: It is a common but incorrect belief that the device is powered solely by the pressure of light (radiation pressure); the thermal effect from the residual gas inside the bulb is a significant factor.
Variants and Related Words
- Radiometer (n): A general device for detecting or measuring radiant energy.
- A microwave radiometer is used in satellite weather observation.
- Light mill: Another name sometimes used for the Crookes radiometer.
Synonyms
- Light mill: A less formal synonym.
- Vane radiometer: A descriptive synonym focusing on its components.
Related Phrases/Idioms
- The term "Crookes radiometer" is a specific technical noun and is not typically used in idiomatic expressions.
Noun
-
electromagnetic radiometer consisting of a small paddlewheel that rotates when placed in daylight
Khám phá thêm
Các từ liên quan
Từ đồng nghĩa
